United States       Air and          EPA/400/1-91/019
              Environmental Protection  Radiation         June 1991
              Agency          (ANR-445)
&EPA      Alternatives for CFC-113
              And Methyl Chloroform in
              Metal Cleaning
                                        Printed on Recycled Paper

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 ALTERNATIVES FOR  CFC-113 AND  METHYL CHLOROFORM
                                IN METAL CLEANING
                                               by
                             ICOLP Technical Committee*
                                   Earl Groshart (Chairman)
                                        George Bohnert
                                       Charles Carpenter
                                        Stephen Evanoflf
                                         John Golden
                                      Greg Hollingsworth
                                         Stewart Holm
                                        Michael Oborny
                                          lrarzan Riza
                                      Ronald Stephenson
                                     Stephen O. Andersen
                            U.S. Environmental Protection Agency
• ICOLP ii the Industry Cooperative for Ozone Layer Protection. ICOLP corporate member companies include AT&T. Boeing Company,
British Aerospace, Compaq Computer Corporation. Digital Equipment Corporation. Ford Motor Company, General Electric. Hitachi
Limited. Honeywell. IBM. Matsushita Electric  Industrial Company. Mitsubishi Electric Corporation. Motorola. Northern Telecom.
Sundstrand. Texas Instruments, and Toshiba Corporation.  Industry association affiliates include American Electronics Association.
Electronic Industries Association. Japan Electrical Manufacturers Association and Halogenated Solvents Industry Alliance (U.S.).
Government organization affiliates include the City of Irvine.. California, the State Institute of Applied Chemistry (U.S.S.R.), the Swedish
National Environmental Protection Agency. U.S. Air Force, and U.S. Environmental Protection Agency (EPA).

Earl Groshan. John Golden and Ronald Stephenson are employed by Boeing; George Bohnert is employed by Allied Signal Aerospace
Stephen  Evanoff is ^employed  by General Dynamics: Stewart Holm is employed by Halogenated Solvents Industry Alliance:  Greg
Hollingsworth is employed by Honeywell: Farzan Riza is employed by ICF Incorporated: Michael Oborny is employed by Sandia National
Laboratories: and Charles Carpenter is employed by the U.S. Air Force. We would like to thank the many individuals and companies that
provided insight and information that helped produce this manual. This manual was funded bv the US. EPA and ICOLP.

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                                                                                      lit
                                Disclaimer
The U.S. Environmental Protection Agency (EPA1, the Industry- Cooperative for Ozone Layer
Protection (ICOLP), the ICOLP committee members, and ihc companies that employ the
ICOLP committee members do  not endorse the cleaning performance, worker safety, or
environmental  acceptability of any of the technical  options discussed.  Every cleaning
operation requires consideration of worker safety and proper disposal of contaminants and
waste products generated from cleaning processes.  Moreover, as work continues, including
additional toxicity testing and evaluation under Section hi2 fSafc Alternatives Policy) of the
Clean Air Act  Amendments  of  1990 and elsewhere, more information on  the  health.
environmental and safety effects of alternatives will become available for use  in selecting
among alternatives discussed in this document.

EPA and ICOLP. in furnishing or distributing this information, do not make any warranty
or representation, either express or implied, with respect to its  accuracy, completeness or
utility, nor does EPA and ICOLP assume any liability of any kind whatsoever resulting from
the use  of. or reliance upon,  any information,  material, or procedure contained  herein.
including but not limited to any claims regarding health, safety, environmental effects  or fate,
efficacy,  or performance, made by the source of the information.

Mention of any company or product in this document is for informational purposes only, and
does not constitute a recommendation of any such company or  product, cither express or
implied by EPA. ICOLP. ICOLP committee members, and the companies that  employ the
ICOLP committee members.

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iv

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                             Table of Contents



List of Exhibits	vii

Foreword	.	*....•	1

      U.S. Clean Air Act Amendments	.1
      Excise Tax	6
      Other International Phaseout Schedules	6
      Cooperative  Efforts	7

Structure of the Manual	9

Introduction to Metal Cleaning	;  . . .	  n

Existing Cleaning Process Characterization	13

      Characterize Solvent Use	  13
      Determine if Solvent Cleaning is Necessary  	  13
      Characterize the Soils and their Sources	15
      Characterize the Substrate ... I	. . . . „	  17

Alternative Method Overview	19

      Organizational	  19
      Technical	;	.19
      Economic	;	23
      Environmental. Health, and Safety	23

Review of Existing Program	25

Alternative Materials and Processes .	^27

      Aqueous Cleaning	28
      Semi-Aqueous Cleaning		34
      Hydrochlorofluorocarbons		38
      N-Methyl-2-Pyrrolidone	44
      Aliphatic Hydrocarbons	46
      Miscellaneous Solvents		48

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 VI
                         Table of Contents (Continued)
 Wastewater Minimization and Treatment	53

       Contaminants	  	53
       Wastewater Minimization	 54
       Wastewater Treatment Technologies  	55
       Conceptual Design of a Wastewater Treatment System	.;.']] 58
       Contract Hauling of Wastewater			.'.'.".* 58

 Summary and Review	        gj

 Case Studies of Industrial Practices	            53

       Case Study #1:  Evaluation of Aqueous Cleaning for Aluminum and
       Ferrous Alloys	"	_      65
       Case Study #2: Selection of Aqueous Process for Cleaning Components
       for Solenoid Valves	59
       Case Study #3: A Five-Phase  Program for Developing Alternative
       Cleaning	72
       Case Study #4: Program to Eliminate  Wipe Solvents Containing
       CFC-113	74
       Case Study #5: Biodegradable Replacements for Halogenated Solvents
       and Cleaners	~	75
       Case Study #6: Replacement of Solvent Degreasing for Engineering
       Prototype Parts. Precision Machine Pans, and Various Cleanroom Items  	79
       Case Study #7: Program to Eliminate Methyl Chloroform Use in
       Steel Chair Manufacturing Operations	80

References	;	g3

List of Vendors for CFC-113 and Methyl Chloroform Solvent Cleaning Substitutes .. 85

Glossary	89

Appendix A - Industry Cooperative for Ozone Layer Protection	93

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                                                                               VII
                               List of Exhibits
Exhibit 1    Montreal Protocol Participants	1
Exhibit 2    Corporate Policies on Cl-C-113 Reduction Schedule	2
Exhibit 3    Phaseout Dates for CFC-113 and Methyl Chloroform Under the
            U.S. Clean Air Act and the Montreal Protocol	4
Exhibit 4    CFC-113 and Methyl Chloroform Usage Profile	14
Exhibit 5    Methods to Eliminate the Need for Cleaning	 16
Exhibit 6    Aqueous Cleaning:  Advantages versus Disadvantages  	29
Exhibit 7    Configuration  of Aqueous Cleaning  Process  in  the  Metal
            Cleaning Industry	,.,..-	30
Exhibit 8    Aqueous Cleaning Process Equipment .		32
Exhibit 9    Semi-Aqueous Process for Immiscible Hydrocarbon Solvent	35
Exhibit 10   Physical Properties of HCFCs and Other Solvent Blends  ........... 40
Exhibit lla  Advanced Design Degreaser for Use with Low Boiling Point
            Solvents	41
Exhibit lib  Stacked Low Emission Degreaser with Solvent Saving
            Features	42
Exhibit lie  Advanced Design Degreaser for Use with Low Boiling Point
            Solvents	.....-	43
Exhibit 12   Summary of Properties of N-Methyl-2-Pyrroiidone  	44
Exhibit 13   NMP Cleaning Processes	45
Exhibit 14   Properties of Aliphatic Solvents	— 47
Exhibit 15a  Properties of Ketones	49
Exhibit 15b  Properties of Alcohols ..	50
Exhibit 16   Properties of Other Chlorinated Solvents	51
Exhibit 17   Semi-Continuous Wastewater Treatment Process .	 59
Exhibit 18   Aqueous Process for Carbon Steel Chair Part  	82

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VIH

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 FOREWORD
The 1987 Montreal Protocol on Substances that
Deplete  the Ozone Layer, and subsequent 1990
amendments and adjustments, restricts the produc-
tion and consumption of ozone-depleting chemi-
cals.   Two such chemicals, chlorofluorocarbon
1.1.2-trichloro- l.Z2-trifluoroethane   (commonly
referred to as CFC-113) and 1.1.1-trichloroethane
(commonly referred to as methyl chloroform or
MCF), will be completely phased out in developed
countries by years 2000 and 2005 respectively, and
ten years later in developing countries.

Exhibit 1 lists the countries that are Parties to the
Montreal Protocol as of April  1991.  In addition.
many companies worldwide have corporate policies
to  expedite the  phaseout  of ozone  depleting
chemicals.   Exhibit 2  presents  the corporate
policies on CFC-113 reduction for some of these
companies.

In addition to providing regulatory schedules for
the phaseout of ozone-depleting  chemicals, the
Montreal  Protocol  established a  fund  that will
finance the incremental  costs of  phasing  out
ozone-depleting substances by developing countries
that are Partv to the Protocol.              :
U.S.  Clean Air Act
Amendments

The U.S. Clean Air Act (CAA) was amended in
1990, and contains several provisions pertaining to
stratospheric ozone protection. Section 602 of the
CAA presents a list of ozone-depleting substances
that are restricted under the CAA.  These ozone-
depleting substances are defined as Class I and
Class II substances. Class I substances include all
fully  halogenated chlorofluorocarbons  (CFCs)
including CFC-113, three halons. MCF. and carbon
tetrachloride.  Class II substances are defined to
include  33  hydrochlorofluorocarbons (HCFCs).
The sections of the CAA that are of importance to
users of this manual are discussed below.
              Exhibit 1
MONTREAL PROTOCOL PARTICIPANTS
Argentina
Australia
Austria
Bahrain
Banetadcsh
Belgium
Brazil
Buleara
Burkina Faso
Cameroon
Canada
Chile
Czechoslovakia
Denmark
Ecuador
Egypt
European
  Community
Finland
Fiji
France
Germany
Ghana
Greece
Guatemala
Hungary
Iceland
Iran
Ireland
Italy
Japan
Jordan
Kenya
Libya
Liechtenstein
Luxembourg
 Malawi
 Malaysia
 Maldives
 Malta
 Mexico
 Netherlands
 New Zealand
 Nigeria
 Norway
 Panama
 Poland
 Portugal
 Singapore
 South Africa
 Spain
 Sri Lanka
 Sweden
 Switzerland
 Syrian Arab Rep.
 Thailand
 The Gambia
 Trinidad and
 Tobago
 Tunisia
 Uganda
 USSR (includes
 Byelorussia and
 Ukraine)
 United Arab
 Emirates
 United Kingdom
 United States
 Uruguay
Venezuela
Yugoslavia
Zambia
Non-Ratifying Signatories:  Congo, Indonesia,
Israel. Morocco. Philippines. Senegal, Togo

                       Date: April, 1991

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                               Exhibit 2
CORPORATE POLICIES ON CFC-113 REDUCTION SCHEDULE
                      Company
  American Electronics Association Member
  Companies. U.S.
  AT&T. U.S.
  Canon.Japan
  Digital Equipment Corporation. U.S.
  Hitachi Corporation. Japan
  Honeywell. U.S.
  IBM, U.S.
  Intel Corporation. U.S.
  Matsushita. Japan
  Motorola. Inc.. U.S.
  Nissan Motor Corp., Japan
  Northern Telecom. Canada
  Seiko-Epson. Japan
  Sharp Corporation. Japan
  Texas Instruments, U.S.
  Toshiba Corporation. Japan
  Volvo, Sweden
'Reduction Schedule
    CFC-113
 Phaseout 2000

 Phaseout 1994
 Phaseout 1994
 Phaseout 1995
 Phaseout 1993
 Phaseout 1997
 Phaseout 1993
 Phaseout 1992
 Phaseout 1995
 Phaseout 1992
 Phaseout 1993
 Phaseout 1991
 Phaseout 1993
 Phaseout 1995
 Phaseout 1994
 Phaseout 1995
 Phaseout 1994

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 Section 604 and Section 605:
 Phaseout of Production and
 Consumption of Class I and Class II
 Substances.                    -     •

 These  provisions  of the CAA present phaseout
 schedules for Class I & Class  II substances.  The
 phaseout dates  for ozone-depleting  substances
 listed in the  CAA are more  stringent than  the
 Montreal  Protocol.    Exhibit  3  presents  the
 phaseout schedule for CFC-113 and MCF. Other
 substances with ozone-deleting potential are also
 regulated under the Montreal Protocol and  the
 CAA.  While they are not used in solvent cleaning
 applications, these substances  are used  in or.hcr
 applications.  Section  605  of  the CAA presents
 provisions for the phaseout of HCFCs. The CAA
 freezes the production of HCFCs  in 2015  and
 phases  them out by 2030. Since these restrictions
 focus on production limitations, to the extent that
 these chemicals can be recovered, recycled, and
 reused, they may continue  in commerce past  the
 applicable phase-out dates.
 Section 608:  National Emissions
 Reduction Program

 This  section   calls  for  EPA  to  promulgate
 regulations by July 1992 requiring emissions from
 all  refrigeration  sectors  (except  mobile  air
 conditioners that are covered in Section 609) to be
 reduced  to  their  "lowest  achievable  levels.*
 Regulations affecting emissions from all other uses
 of Class I and Class II substances including solvent
 cleaning  are  to take effect by November 1995.
 This  section also  prohibits  any  person from
 knowingly venting any of the controlled substances.
 including HCFCs, during servicing of refrigeration
 or  air  conditioning  equipment  (except  cars)
 beginning Jury  1, 1992, and  requires the safe
 disposal of these compounds by that date.
Section 610: Nonessential Products
Containing Chlorofluorocarbons •

This  provision  directs  EPA  to  promulgate
regulations that prohibit the sale or distribution of
certain "nonessential' products that release Class I
& Class  II substances during manufacture,  use,
 storage, or disposal. In the CAA. Congress defined
 several produce as nonessential including CFC-
 containing  cleaning  fluids  for noncommercial
 electronic and photographic equipment, and CFC-
 propelled plastic parry streamers and noise horns.
 In addition. Congress established  guidelines to
 identify additional  products that are nonessentiaL
 Regulations  tanning  nonessential  products that
 release Class I substances must be promulgated by
 November 15,1991 and become effective Novem-
 ber 15, 1992. In addition, the CAA bans the sale
 and distribution of certain products releasing Class
 II substances, including aerosols and  pressurized
 dispensers and noninsulating foam,  by January 1,
 1994.  Exemptions can be granted from the ban on
 aerosols  and  pressurized   dispensers  due   to
 flammabili'ty aid worker safety concerns.
 Section 611: Labeling

 This  section  of  the  CAA  directs   EPA to
 promulgate regulations by May 15,1992 requiring
 labeling  of  products  that  contain   or  were
 manufactured vhh Class I or Class II substances
 and containers containing these substances.  The
 label will read "Warning:  Contains or  manufec-
 tured with [insert name of substance], a substance
which harms poblic health and environment by
destroying ozone in the upper atmosphere".

The CAA defines three types of products that must
be labeled awf specifies the time frame  by which
these  products  must  be  labeled.   The  three
products  and time frame are as follows:

• Effective May 15, 1993,  containers in which a
  Class  I or  Class  II substance  is  stored or
  transported, and products containing Class I
  substances must be labeled;

• Effective May 15, 1993, products manufactured
  with Class  I  substances  must  be  labeled.
  However, products manufactured with Class I.
  substances can be temporarily exempted from
  the labeling requirements of this section if EPA
  determines that there are no substitute products
  or manufacturing processes that (a) do not rely
  on the  use of the Class I substance, (b) reduce
  the overall  risk to human  health  and  the
  environment, and (c) are currently or potentially
  available. If EPA temporarily exempts products

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                                   Exhibits
PHASEOUT DATES FOR CFC-113 AND METHYL CHLOROFORM
                  UNDER THE U.S. CLEAN AIR ACT
                  AND THE MONTREAL PROTOCOL
 CFC PHASEQUT

   Clean Air Act

    Reduce from 1986
    levels by:      :
      1991 - 15%   '-•
      1992-20%"
      1993-25%
      1994 - 35%
      1995 - 50%   •
      1996-60%
      1997 - 85%
      1998 - 85%
      1999 - 85%
     2000 - 100%
                               Montreal Protocol
                               Freeze at 1986 production and consumption levels by July
                               1989
                               20% reduction from 1986 levels by January 1993
                               50% reduction from 1986 levels by January 1995
                               85% reduction from 1986 levels by January 1997
                               100<ฃ reduction from 1986 levels by January 2000

                               Also call for future assessment to determine if an earlier
                               complete phaseout by January 1997 is achievable
METHYL CHLOROFORM PHASEOUT
                              Montreal Protocol
                              Freeze at 1989 production and consumption levels by
                              January 1993
                              30% reduction from 1989 levels by January 1995
                              70% reduction from 1989 levels by January 2000
                              100% reduction from 1989 levels bv January 2005
   Clean Air Act

     Freeze at 1989 levels
     by 1991
     Freeze at 1989 levels
     continues in 1992
     Reduce from 1989
     levels by:
      1993-10%
      1994 - 15%
      1995 - 30%
      1996 - 50%
      1997 - 50%
      1998-50%
      1999 - 50%
      2000-80%
      2001-80%
      2002-2004*
      2005 - 100%

•New authority would be given to EPA to authorize, to the extent consistent with the Protocol, the
production of methyl chloroform in an amount not to exceed 10% of baseline per year in 2002,2003,
and 2004 for use m essential applications for which no safe substitutes are available.

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 manufactured with  Class I substances from  the
 labeling  requirement  based  on  the  lack  of
 substitutes, the  products  must be  labeled  by
 January 1, 2015: and

 •  No  later  than  January  1.  2015.  products
   containing  or manufactured with a  Class II
   substance must be labeled.  EPA may require
   such products to be labeled as early as May 15.
   1993  if it  determines,  after  notice  and
   opportunity for public comment, that there  are
   substitute products or manufacturing  process
   available.

 The CAA allows for petitions to be submitted to
 EPA to apply the requirements of Section 611 to
 products  containing Gass  II substances or a
 product manufactured with Class I or II substances
which  are   not   otherwise  subject   10   the
 requirements.  This  petition process will operate
 between May  15. 1993 and January I. 2015.  Fror
 products manufactured with Class I substances, a
 successful petition would result in the labeling of
 a product previously determined by EPA to  be
exempt. For products containing or manufactured
with Class II substances, the petition process could
 lead to labeling of a product that  had been left
unlabeled bv default.
Section 612: Safe Alternatives Policy

'Section 612 establishes a framework for evaluating
the environmental  impact  of current and future
potential alternatives.  Such regulation ensures
that the substitutes for ozone-depleting substances
will not create environmental problems themselves.
The key provisions of Section 612 require EPA to:

•  Issue rules by November 15, 1992 which make
   it unlawful to replace any Class I  and Class II
   substances with a substitute that  may present
   adverse  effects  to  human   health  and  the
   environment  where  EPA  has  identified an
   available or potentially available alternative that
   reduces  the overall risk to human health and
   the environment.

•  Publish  a  list   of   prohibited   substitutes,
   organized  by use  sector, and  a   list of the
   corresponding alternatives:
 •  Accept petitions to add or delete a substance
    previously listed as a prohibited substitute or an
    acceptable alternative:

 •  Require  any  company  which  produces a
    chemical substitute for a Class I substance to
    notify EPA 90 days before any new or existing
    chemical  is  introduced  into  commerce as a
    significant  new  use of  that  chemical.   In
    addition,,  EPA  must  be  provided  with  the
    unpublished health and safety studies/data on
    the substitute.

 To implement Section 612 EPA will (1) conduct
 environmental risk characterizations for substitutes
 in  each  end  use and (2) establish the Significant
 New Alternatives Program (SNAP) to evaluate the
 future  introduction of substitutes for  Class  I
 substances. EPA has also initiated discussions with
 NIOSH.  O'SHA. and  other governmental  and
 nongovernmental  associations  to  develop  a
 consensus process  for establishing  occupational
 exposure limits for the most significant substitute
 chemicals.

 The environmental risk characterizations for the
 substitutes will involve a comprehensive analysis
 based on the following criteria:  ozone-depleting
 potential, flammability, toxiciry, exposure effects,
 energy efficiency, degradation impacts, air, water,
 and solid waste/hazardous waste pollution effects,
 and global warming potential.  Economic factors
 will also be considered. EPA will organize these .
 assessments   by   use   sector   (i.e.   solvents,
 refrigeration, etc). The risk characterizations will
 result  in  risk-management  strategies  for each
 sector and substitute. EPA will then categorize a
 substance  as   unacceptable,  acceptable  with
 limitations on use or quantity, acceptable without
 comment,  or  delayed pending  further  study.
 Petitions will be allowed to change a substance's
status with the  burden of proof on the petitioner.

The SNAP program, effective November 15,1992,
will review future substitutes not covered  in the
initial risk characterization process.  SNAP will  '
evaluate   a substitute  based  on the  criteria
established for  the  risk characterization and will
classify it similarly.

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    Excise  Tax


    Congress has also placed an excise tax on ozone-
    depleting chemicals manufactured or imported for
    use in the United States.  This tax provides  a
    further incentive to use alternatives and substitutes
    to CFC-113 and MCR The tax amounts are based
   on each solvent's ozone depleting potential.

Calendar Year

1991
1992
1993
1994
1995
Tax Amount
Per Pound
CFC-113 MCF
S1.096 S0.137
S1336 SO. 167
S2.120 S0.265
S2.120 S0.265
S2.480 S0.310
The tax will increase bv S0.310 per pound
for CFC-113 and S0.045 per pound for
MCF each year after 1995.
  Other International Phaseout
  Schedules
 European Community Directive

 Under the Single European Act of 1987. the twelve
 members of the European Community (EC) are
 now subject to various environmental' directives
 The members of the EC are Belgium. Denmark!
 Germany, France, Greece, Great  Britain, Ireland,
 Italy, Luxembourg, the Netherlands. Portugal, and
 Spam.   Council Regulation number 594/91 of
 Mtrch 4, 1991 provides regulatory provisions for
 the  production of substances  that deplete the
 ozone layer. The EC phaseout schedule for CFC-
 113  production is  more  stringent  than  the
Montreal Protocol,   it  calls  for a 50 percent
reduction of CFC-113 by the end  of 1993  a 67.5
percent reduction by the end of  1995  an  85
percent  reduction  by  the end  of 1996  and
complete phaseout by June 30,  1997. For MCF
    the production phaseout schedule is as follow!!: 30
    percent reduction by the end of 1995, 70 percent
    by the end of 2000. and a complete phaseout bv
    the end of 2004. While all members must abide by
    these dates. Council Regulation number 3322JSS of '
    October 31.1988 states that EC members may lake
    even more extensive measures to protect the ozone
    layer.
   Other Legislation

   Several other countries have adopted legislation
   that  is more stringent  than  the terms of the
   Montreal  Protocol:  Environment Canada, the
   federal environmental  agency  responsible for
   environmental protection in Canada, also has a
   reduction  program in place that is more stringent
   than the Montreal Protocol. All production and
   import of CFCs. for use in  Canada,  must  be
   eliminated by no  later than 1997.  Environment
   Canada has also announced a series of target dates
   for the phaseout of CFCs in specific end uses. For
  solvent cleaning applications, such  as metal and
  precision cleaning, it mandates a phaseout of CFC-
  113  by  the  end of  1994.    Pending  final
  consultations  with  end-users and producers of
  MCF, the target date for the phaseout of MCF will
.  be 2000.

  Japan  has ratified the  revised Montreal Protocol.
  The recent Ozone Layer Protection Act gives the
  Ministry of International  Trade  and Industry
  (MITI) the authorization to promulgate ordinances
  governing the use of ozone-depleting compounds.
  MITI  and  the  Environmental  Agency have
  established   the  "Guidelines   for   Discharge
  Reduction and Use Rationalization." Based upon
  these guidelines,  various  government  agencies
 provide administrative guidance and advice to the
 industries  under their respective  jurisdictions"
 Specifically. Mm, the ministry overseeing several
 aspects  of  Japanese  industry  including  the
 production  and  trade  of controlled substances,
 prepares and distributes manuals, and encourages
 industry to  reduce  ozone-depleting  compounds
 consumption through economic measures such as
 tax incentives to promote the use of equipment to
 recover and  reuse solvents.

The EFTA  (European  Free Trade Agreement)
countries (i.e., Austria. Finland, Iceland, Norway,

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  Sweden,  and Switzerland)  have  each adopted
  measures to completely phaseout fully halogenaied
  ozone-depleting compounds.  Some of the EFFA
  countries have  sector-specific  interim phaseout
  dates for certain solvent uses.  Norway and Sweden
  will  phaseout  their use  of  CFC-113   in  all
  applications except textile dry cleaning by July 1
  and January 1, 1991. respectively.   Furthermore.
  Austria will phaseout CFC-113 in  some  solvent
  cleaning applications by January 1.1992 and 1994.
  Austria. Finland.  Norway,  and Sweden will  all
  completely phaseout their use of CFC-113  in all
  applications by January 1,1995.  Sweden also plans
  an aggressive phaseout date of 1995 for MCF.  ,
 Cooperative  Efforts


 The U.S. Environmental Protection Acency i EPA1
 has been  working with industry to disseminate
 information on technically feasible, cost effective.
 and environmentally sound alternatives for ozone-
 depleting substances.  As pan of this  effort, the
 U.S. EPA is working with the Industry Cooperative
 for Ozone Layer Protection (ICOLP*)  to prepare
 a series of manuals  to provide  technical infor-
 mation on alternatives to CFC-113 and MCF. The
 manuals are based on actual industrial experiences
 that will serve as a guide to users of CFC-113 and
 MCF worldwide.  These manuals  will be updated
 periodically as technical developments occur.
                                            i
 The first manuals in the series are:

 •  Conservation and Recycling Practices for CFC-
   113 and Methyl Chloroform.
                                            (
 •  Aqueous and Semi-Aqueous Alternatives to
   CFC-113 and Methyl Chloroform Cleaning of
   Printed Circuit Board Assemblies.

 •  Inert  Gas Soldering/Low  Residue  Flux  and
   Paste Alternatives  to  CFC-113  and  Methyl
   Chloroform.
•  Alternatives   for   CFC-113   and
   Chloroform in Metal Cleaning.
Methvl
  • Eliminating CFC-113 and Methyl Chloroform in
    Precision Cleaning Operations.

  • Riveting  Without   CFC-113   and  Methyl
    Chloroform.

  This particular manual will take you. an individual
  in an  industrial organization involved  in metal
  cleaning operations, through  a simple structured
  program to help you eliminate use of  CFC-113
  and/or MCF-'. This manual:

  •  Provides you with some background on metal
    cleaning:

  •  Guides you through a characterization of your
    existing process:

  •  Outlines she criteria to consider as you develop
    and  select the appropriate  alternative for your
    operations:

 •  Introduces several alternative technologies; and

 •  Presents  detailed  case  studies  on actual
    industrial applications of these technologies.

 The alternatives to CFC-113 and MCF for metal
 cleaning discussed in the manual are:

 • Aqueous cleaning

 • Semi-aqueous cleaning

 • Alternative solvents.

 This manual will benefit all users of CFC-113 and
 MCF in metal cleaning.  Ultimately, however, the
 success  of your CFC-113 and MCF elimination
 strategies will depend upon how effectively you can
 coordinate  your  reduction  and   elimination
 programs. The development and implementation
of alternatives to CFC-113 and MCF for metal
cleaning  present  an exceptionally  demanding
challenge for your organization. The rewards for .
success   are   the   contribution   to   global
environmental protection and the increase in your
company's industrial efficiency.
• Appendix A presents more detailed information
about ICOLP.

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STRUCTURE OF THE MANUAL
This manual is divided into the following sections:
  •  INTRODUCTION TO METAL CLEANING

     This section provides a brief description of metal cleaning.


  •  EXISTING CLEANING PROCESS CHARACTERIZATION

     This section describes the tools to characterize metal cleaning operation.  It is
     important to understand the relationship between metal cleaning and the other
     aspects of manufacturing processes and how CFC-113 and/or MCF are used.
                                i

  •  ALTERNATIVE METHOD OVERVIEW

     This section highlights the criteria for developing and selecting a non-CFC/MCF
     strategy for metal cleaning.  Various technical and managerial considerations are
     discussed.


  •  ALTERNATIVE MATERIALS AND PROCESSES

     This section describes the operational principles and outlines the advantages and
     disadvantages of each technology.


  •  WASTEWATER MINIMIZATION AND TREATMENT

     This section presents methods to minimize and treat; wastewater from aqueous
     and semi-aqueous cleaning processes.


  •  CASE STUDIES OF INDUSTRIAL PRACTICES

     This section describes case studies that illustrate the successful implementation of
     alternative technologies.

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10

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  INTRODUCTION  TO  METAL  CLEANING
 Cleaning is an essential process in the production.
 maintenance, and repair of manufactured articles.
 As a surface preparation process, cleaning removes
 contaminants and prepares raw materials and pans
 for subsequent  operations such as machining,
 painting, electroplating, inspection, and packaging.
 Cleaning is used in furniture and  fixtures, primary
 metal  industries,  fabricated metal   products.
 machinery,  transportation equipment, and other
 miscellaneous manufacturing.

 Chlorofluorocarboh  113  (CFC-113) and  methyl
 chloroform (MCF)  have been  used  for  many
 solvent  cleaning  applications.   These solvents
 exhibit good solvency for a wide variety of oreanic
 contaminants  and are noncorrosive to the metals
 being cleaned.    They  have  low  heats  of
 vaporization and  high vapor pressures  that are
 beneficial in vapor cleaning processes and allow
 evaporative drying of cleaned pans. Additionally.
 these  solvents are  non-flammable, have  low
 toxicity,  and  chemically  stable  when  properly
 formulated with adequate stabilizers.

 Solvent cleaning may be  divided  into two types:
 cold cleaning and vapor decreasing. Cold cleaning
 is usually accomplished with solvents at. or sliehtly
 above, room temperature.  In cold cleanine. parts
 are  cleaned  by  being  immersed  and  soaked.
 sprayed, or wiped  with the solvent.

 Vapor degreasing is a  process that  uses the boiling
 solvent vapor  to remove contaminants.  A basic
 vapor degreaser consists of an open-top steel tank
 that has a heat source at  the bottom to  boil the
 solvent and cooling coils near the upper section to
 condense the vapors.

 Heat,  introduced  into  the  reservoir, boils  the
solvent and  generates hot solvent vapor which
displaces  the lighter air and forms a vapor zone
above the boiling solvent up to the cooling zone.
The hot vapor is condensed when it  reaches the
cooling zone by condensing coils or a water jacket.
thus maintaining a fixed vapor level and creating a
 thermal balance. The hot vapor condenses on the
 cool pan suspended in the vapor zone causing the
 solvent to dissolve or displace the contaminants or
 soils.

 Vapor decreasing is.  in most applications, more
 advantageous than  cold cleaning, because in cold
 cleaning  the  solvent  bath becomes  increasingly
 contaminated.   Although  the boiling  solvent
 contains the contaminants from previously cleaned
 parts, these usually hoil at higher temperatures
 than the solvent, resulting  in  the formation of
 essentially pure solvent vapors.  In addition, the
 high temperature of vapor cleaning aids in wax and
 heavy  grease removal  as  well as  significantly
reducing the time it takes for cleaned pans to dry.

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12

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                                                                                   13
EXISTING CLEANING  PROCESS
CHARACTERIZATION
To develop an effective program to reduce and
eliminate the use of CFC-113 and MCF. you must
first acquire a  good knowledge  of your plant
operations. The types of questions you should be
able to answer include the following:
   •   What  materials/substrates arc you
      cleaning?

   •   Where are the contaminants  coming
      from?

   •   What types of contaminants are you
      removing?

   •   Why are  you performing  metal
      cleaning at your plant?

   •   Is this cleaning step necessary?

   •   What are the effects of metal cleaning
      on  the upstream and  downstream
      aspects of your process?

   •   What processes are using CFC-113
      and MCF?

   •   Where  do   CFC-113  and  MCF
      emission losses take place?

   •   Who purchases CFC-113 and  MCF?

   •   Who accepts delivery of CFC-113 and
      MCF?

   •   How are CFC-113 and MCF handled
      from arrival to ultimate use?
Characterize  Solvent Use

The first step in addressing the use of CFC-113
and MCF is to designate a team to coordinate the
solvent reduction and elimination programs. Team
members should represent various plant functions
including   process   design,   production  and
production engineering,  environmental control.
occupational health and safety, quality control, and
purchasing. The team leader of the reduction and
elimination programs should conduct a survey to
determine the quantities of CFC-113  and MCF
used in every aspect of the plant's operations. An
example survey form that could be used for this
purpose is shown in Exhibit 4.  Material Safety
Data  Sheets are  useful  in identifying  the
composition, of solvents.
   The total quantity of CFC-113 and MCF
   used in your processing should be divided
   by the appropriate production unit for
   your operations  to obtain the ratio  of
   kilograms  or  pounds  of CFC-113 and
   MCF used per  production unit  This
   value  will be  your  benchmark  for
   reduction and elimination programs.
Determine if Solvent
Cleaning Is  Necessary

After identifying the processes where solvents are
being used, ihc next step is to determine whether
each cleaning  step is necessary.   The entire
production system should be viewed with a focus
on  improved  procedures,   housekeeping,  and
process changes to eliminate soiling of pans.

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14
                                      Exhibit 4
      CFC-113 AND  METHYL CHLOROFORM  USAGE  PROFILE
  A. Identification
  Name of Product:
  Manufacturer
  Purchase Number
  CFC or MCF Components:
                        Chemical Name
                                                         Percent, or Concentration
  B.  Quantification of Usage Patterns
  Quantity Purchased: .(specify units)
     1989:
     1990:
  C.  CFC and MCF Disposal
 Annual quantity shipped out as waste
 for disposal:  (specify units)
 Annual disposal costs:
 Annual quantity shipped out for
 reclamation:  (s'pecify units)
 Annual cost of reclamation:
 Annual quantity lost to the
 environment: (specify units)
    Through leakage:
    Through spillage:
    Through testing:
    Through dragout and
    evaporation:
    By other means (specify)
    Unaccounted for.
Source:  U.S. EPA 1990

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                                                                                                  T5
 A suggested hierarchy of options is:

    Reduce or eliminate soiling of parts:

 •  Improve housekeeping:

 •  Consolidate operations.

 For example, in a  number of metal  finishing
 processes, solvent cleaning is followed by alkaline
 cleaning.  The question to ask is whether alkaline
 cleaning can handle the soil  loading if the solvent
 cleaning step is eliminated. The answer may be yes.
 Or, if chip removal is desired,  can a  mechanical
 means (such as air  blow-off,  water spray/flush)
 replace solvent cleaning?

 Another useful step  is to evaluate the processes
 where  solvent is  being  used, and  determine
 whether alternative materials would make solvent
 cleaning unnecessary.  Exhibit 5 presents methods
 that could be considered.   For example, if the
 process  before the  solvent cleaning  step  was
 changed as  suggested in Exhibit  5.  could the
 solvent cleaning step be eliminated?  If the answer
 is no, it will be necessary to find alternative solvent
 cleaning methods. These alternatives arc discussed
 later.                                   .
 Characterize the Soils and
 Their Sources

 A critical part of the  initial stage of process
 evaluation is  characterizing the  soils and  their
 sources.   This  study  of existing materials  and
 procedures will help identify means of eliminating
 the need  for cleaning or reducing the amount of
 soil to be removed.

 Conduct a factory survey to characterize the soils
 and  identify their sources.   This survey  should
 include  visits  to  each   production  process,
 observation of existing procedures, interviews with
 operators of the equipment, and collection of soil
 samples  for preliminary laboratory  tests.   Tliis
 process will provide firsthand experience and also
 establish contact and develop  rapport with  the
 individuals who will ultimately be effected by the
 process change.  Their cooperation and input are
essential  to the success of the program.
 The general category of the soils that are removed
 needs to be determined. The types of soils can be
 generally classified into five groups:

 •  Pigmenitcd  drawing. compounds are used in
    process  steps  where  the metal is extruded
    through dies to  produce parts.   The most
    commonly used pigmemed compounds contain
    one or  more of  the  following substances:
    whiting, lithopone, mica, zinc oxide, bentonite,
    flour,   graphite,   white  lead,   molybdenum
    disulfidc.  titanium  dioxide, and  soap-like
    materials.

 •   Unpigmented oil and grease include common
   shop oils and greases such as drawing lubricants,
   rust preventive oils, and quenching oils.

 ป  Forminc:  lubricants  and  fluids  used  for
   machininc   tan  he  classified  into  three
   subgroups:  (1) hydrocarbon-based oils:  plain
   or  sulfuri/ed mineral and  fatty  oils  (or a
   combination  of the two), chlorinated mineral
   oils, and sulfurizcd chlorinated mineral oils, (2)
   soluble/emulsifiable oils: conventional or heavy
   duty soluble oils containing sulfur  or  other
   compounds,  glycol  ethers,  glycols  or  other
   emuisificrs   added,   and   (3)  water  soluble:
   chemical cutting fluids that are  water soluble
   and contain  soaps,  amines,  sodium salts  of
   sulfonated fatty alcohols, and alkyi  aromatic
   salts of sulfnnatcs.

•  Polishing and buffing compounds can also be
   classified into three subgroups: (1) liquids:
   mineral oils  and  oil-in-water  emulsions or
   animal  and  vegetable  oils  with  abrasive
   materials. (2) semi-solids: oil-based containing
   abrasives  and   emulsions   or   water-based
   containing abrasive and dispersing agents, and
   (3)  solids:   grease  containing   stearic  acid,
   hydrogenated fatty acids,  tallow, hydrogenated
   glyceride, petroleum waxes, and combinations
   that   produce   either    saponifiable   or
   nonsaponifiable  materials   in   addition  to •
   abrasive materials.

•  Miscellaneous  surface contaminants  such as
   lapping  compounds,  residue  from  magnetic
   panicle inspection, hand oils, shop dirt, chips,
  airborne dust, finger grease, ink marks, barrier
  cream,  or hand protective  cream and  metal
  pieces also exist.

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16
                                       Exhibits


        METHODS TO ELIMINATE THE NEED FOR  CLEANING
    Soil Presently Removed
    by Chlorinated Solvent
  Hydraulic Fluids - Phosphate
  Esters
  Magnetic Inspection Field
  Kerosene
  Hydrocarbon Greases and
  Oils
  Fats and Fatty Oils

  Polishing Compounds - Fats
 Machining Compounds -
 Cutting Fluids
 Corrosion Inhibiting
 Compounds
 Drawing Compounds

 Forming Compounds

 Ink Marks
 Fingerprints


 Mill Oils
             Methods Which Reduce Solvent Use
 Prevent spills and leaks.  Sorbcm materials can be used.
 Sorhcnt materials can be used. Water carriers to replace the
 orgamcs can be considered.

 Hand wiping stations can remove enough material to allow
 alkaline cleaning.  Water soluble compounds can be used.
 Handwipe or use alkaline cleaners.

 Water-soluble compounds may be substituted.  Cleaning at the
 polishing station should be considered.

 Water-soluble compounds should be considered.
Alkaline-soluble compounds can be considered.  Protective packaging
may eliminate cleaning need.

Water-soluble compounds can be used.

Water-soluble compounds can be used.

Water-soluble inks can be used and removed with water-based
cleaners.  Use labels or tags until final marking applied.

If all fabricated parts are handled with gloves, fingerprints will be
minimized. Hand alkaline wipe to remove.

Protective packaging eliminates cleaning need.  Sorbent materials
may be used to remove oils.

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                                                                                                 17
 The sources of the soils must be identified.  For
 example, are the soils:

 •  Received as raw material?         -

 •  Produced in forming/stamping operations?

 •  Produced in general machining operations?

 •  Produced in sub-assembly? and/or

 •  Received with vendor parts?

 Once the  soils and their sources  have  been
 identified, the solvent elimination process can be
 optimized.  For example, the type of soils can be
 consolidated  by   reducing   the   number  of
 processing/machining fluids and switchinc to water-
 soluble alternatives.  It is common practice to use
 a wide variety of processing fluids: in most cases
 this can be avoided. Review the Material Safety
 Data Sheets for all the processing fluids that are
 being used and select the acceptable ones.

 Try to  use water-soluble  and non-chlorinated.
 emuisifiable  machining  and  metal  forming
 lubricants.    These  products  require smaller
 quantities to perform a given task, and are  more
 compatible  with   alkaline  cleaners  than  with
 halogenated solvents and are generally emulsified
 and removed from substrates at lower temperature-
 concentration   conditions   than   are   neat
 hydrocarbon oils.    Lubricant  spray applicators.
 which discharge a  fine, well-controlled mist, can
 also decrease lubricant  usage  without affectine
 product quality.

 Other rypes of alternative metal forming lubricants
 under development include "dry* lubricants  and
 thin polymer sheeting which can be peeled  from
 the surface after the metal forming operation.

 The handling, packaging,  and routing of parts
 through  the  production  process  should  be
 reassessed to minimize the number of times a pan
 is soiled and cleaned. Put particular emphasis on
consolidating, if possible, cleaning operations into
a centralized unit or location. This step improves
control of waste, emissions, and usage.

Segregation  and  precleaning of parts can extend
bath  life and  make  cleaning  more  efficient.
Heavily soiled pans should be  routed separately
 through  a.  single  precleaning  system,  thereby
 concentrating soils in one cleaning process.
 Characterize the Substrate

 The  selection of the cleaning  process must be
 based not only on the soils being removed, but also
 on the substrates being cleaned.   In evaluating
 alternative cleaning processes, it is important to
 characterize  the substrate/material being cleaned.
 This  includes evaluation of:

 •  The type of substrate used:

 •  The  si/c  and geometry  of the  pan  being
   cleaned:

 •  The porosity of the part.

 Metals such  as aluminum  and alloys containing
 magnesium,  lithium, and  zinc require special
 consideration because of their sensitivity to attack
 by certain chemicals.  For example, cleaners for
 aluminum    are   generally  mildly  alkaline
 (approximately  9-10  pH),   while' those  for
 magnesium and steel arc best used above 11 pR
 Zinc  and cadmium are subject to  corrosion and
 pitting by alkaline solutions.

 Parts with excessive porosity such as coatings, parts •
 that have severely rough surfaces, parts that have
 permanent overlapping joints (i.e.. rivet joints, skip
welded,  and  crimp joints),  and parts  with  blind
holes  and tubing can retain solution - which can
cause, corrosion.

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                                                                                           19
 ALTERNATIVE METHOD  OVERVIEW
 In  developing  and  selecting  an  alternative
 technology for metal cleaning,  several criteria
 should  be considered.   These  considerations
 include:
    •   Organizational

    •   Technical

    •   Economic

    •   Environmental, Health, and Safciv
Organizational

Important considerations include:           ',

•  Compatibility   with   other  corporate  goals.
   Corporate policy  might  disallow the use of
   particular solvents because of their impact on
   product quality.

•  Feasibility given easting organizational structure.
   Environmental concerns  may already be  the
   responsibility of a particular task force within
   the company.   Some companies have made
   environmental  performance a  criterion  for
   evaluating managerial performance.

•  Compatibility with corporate environmental policy.
   Some alternatives generate other forms of
   emissions, effluents, or wastes that are also the
  subject of corporate environmental goals.   \
Technical

The technical feasibility of the alternative process
must be evaluated on a case-by-case basis.  The
first step is to develop criteria for evaluating the
alternative process taking into account applicable
federal,  state, and  local  regulations that might
apply. As discussed in the Foreword Section, the
Clean Air Act Amendments of 1990 have several
provisions  pertaining  to  stratospheric ozone
protection that must be considered before selecting
alternatives.  These include Section 608: National
Emissions  Reduction  Program. Section  611:
Labeline. and Section 612:  Safe  Alternatives
Policv.
   Important  technical  considerations  in*
   elude:

   •   Chemical cleaning ability

   •   Physical and chemical characteristics
      of cleaning process

   •   Compliance to specifications

   •   Material compatibility

   • '   Effect on subsequent processes

   •   Process control

   •   Production rate requirements

   •   Ease of new process installation

   •   Floor space requirements

   •   Operating and maintenance require-
      ments.

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   20
   Chemical Cleaning Ability

   The question of cleanability can be the source of
   many hours of meetings, discussions, and testine.
   The  degree of cleanliness required varies  from
   industry to industry and from process to process.
   In some  metal cleaning applications, cleanliness
   requirements   are  less  stringent   in  terms  of
   measurable residue  while in  industries  where
   critical   components   are   being   cleaned.
   requirements  may  be more stringent.   Meeting
   cleanliness standards in the aerospace industry may
   require the removal of all damaging contaminants.
   The high performance coatings and adhesives used
   on jet aircraft require, for example, a high degree
   of surface cleanliness  to insure the integrity of'the
   coatings and to guarantee  that adhesives are not
   adversely affected.

   The removal of contamination from a surface is
   not a  single property of a solvent, but a combined
   relationship of several characteristics.  Some of
   these  characteristics include wetting, capillarity,
  detergency, solubility, and emuisification.

  Several standard tests can be used to determine the
  cleaning ability of the alternative process. Some of
  these  tests can be run on the shop floor (visuals.
  tissue  paper test, water  break, and  acid copper
  test),  whereas  other  tests would   have  to  be
  performed in a laboratory.

  •  Visual Examination. This test is useful only for
    visible contamination, but it can be done in a •
    production/plant environment.

•• Tissue Paper Test.  The cleaned surface is rubbed
    with  white  tissue  paper  and the  tissue is
    observed for stains.  This test is simple and can
    be done in the production/plant environment.

 • Water Break.   If the last clean rinse  forms a
    continuous water film on the pan  as  it is
    removed, the surface can  be considered clean.

 • Add Copper Test.  A ferrous panel is immersed
    in a copper sulfate solution. On clean surface
   areas, copper will be  deposited by chemical
   activity, forming a strong  adherent, semi-bright
   coating that is spot free.

 • Atomizer Test.  Water mist is applied to a clean
   dry surface with an atomizer.  The cleanliness is
                    •
    determined  by the  value  of  the  advancing
    contact angle.

  • Contact Anrfe of Water Drop. A drop of water is
    placed on the test surface: the contact angle is
    then measured either photographically or by a
    contact angle goniometer.  Although this is an
    accurate method of determining relative surface
    cleanliness, it can only be used under laboratory
    conditions.

  •  Kerosene Viewing of Water Break.  The test panel
    is withdrawn from  water and is immediately
    submerged  in  a  transparent  container   of
    kerosene  that  is  lighted  from  the  bottom.
    Water   breaks  are  displaced  by kerosene.
    (Kerosene is  combustible, so  be careful  whem
    using this method.)

 •  Radioactive  Tracer.     A  radioactive  soiling
    compound is applied to the test piece, and the
    residual radioactivity is measured after cleaning.
    This is  the most sensitive of the quantitative
    tests now available.  Use standard precaution!!
    when working with radioactive materials.

 •  Fluorescent Dye.  An oil soluble fluorescent dye
    is  mixed with  an  oily soiling  material and
    applied  to the test panels. After the panels are
    cleaned, the  retained  soil  is  visible  under
    ultraviolet  or black  light.   Note  that some
   cleaners may  selectively  remove  tracer or
   fluorescent dyes.

 •  Gravimetric. The test panels are weighed before
   and after cleaning.    The sensitivity  of the
   method  depends upon  the sensitivity, of the
   balance  and the size of the panel.

•  Oil Spot.  A drop of solvent is used to degrease
   an area the size of the drop. The drop is picked
   up  with  a pipette and evaporated on ground
   glass. An evaporation ring indicates contamina-
   tion.

• Paniculate Contamination.   A thin film of
   polyvinyl chloride is  pressed  against the  test
  surface, heated to 240ฐF, and cooled. It is then
  carefully  stripped  from   the surface  and
  examined  under  the   microscope.     The
  paniculate contaminants will be embedded in
  the vinyl sheet.

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                                                                                                ZT
 • Particle Removal Test. Panicle removal can be
   tested by artificially contaminating surfaces with
   known  panicles of various sizes down to  and
   below the size of interest for removal.  Precision
   panicles from submicron to tens of microns in
   size can be obtained. Nephelometric methods
   and membrane  filtration  methods  such  as
   ASTM-F24 are useful low-cost techniques for
   evaluating general cleaning.               :

 • Chemical Analysis. Surface cleanliness can be
   evaluated and surface contaminants  identified
   and quantified by using a number of  analytical
   chemical techniques.  The techniques most often
   used are Auger electron  spectroscopy (AEiS),
   secondary ion mass spectroscopy (SIMS), x-ray
   photo-electron   spectroscopy   (XPSX  and
   microscopic   Fourier-Transform   infrared
   spectroscopy (micro FT-IR).

 •  Optical   Monitoring   and   Polarized   Light
   Microscopy. Visual inspection using microscopy
   is relatively inexpensive and gives fast results.

 •  End Use Tests. These tests can be conducted to
   examine the effect of cleaning on subsequent
   process  steps  such  as  the  application   of
   protective coating (some of these are discussed
   later in this section).
Physical and Chemical Characteristics
of the Cleaning Process

Physical  and chemical  characteristics  include
viscosity, surface  tension, density,  boiling point.
freezing point, specific heat, and latent  heat of
vaporization.  These propenies  determine the
cleaning effectiveness.
Compliance to Specifications

In  instances where  cleaning  requirements  are
governed by military or other specifications, it is
necessary   to  either   verify  compliance   by
demonstrating  that  cleaning   is  adequate  or
renegotiate existing specifications before switching
to alternative technologies.
 Material Compatibility

 In the selection of an alternative process, material
 compatibility is important. Issues to be considered
 include corrosion problems and compatibility with
 various process materials, such as metals, plastics.
 elastomers,   composites,  and other sensitive
 materials.

 Compatibility problems  can  be  evaluated  by-
 performing a number of corrosion tests:

 •  Intergranular attack testing determines if the
   cleaning solution unacceptabty weakens the test
   metal by selectively removing  material along
   grain boundaries.

 •  Stress corrosion (ASTM-G38) cracking (SCC)
 -  of pans can occur when susceptible materials
   (from which the parts are made) are corrosion
   sensitized during cleaning and are subsequently
   aged in ii tension stress application.  In general
   SCC tests are run by subjecting a test specimen
   of the same composition and heat treatment as
   the pan, to a constant tension stress load after
   being exposed to the  corrosive medium.  A
   number of ASTM test methods specify complete
   test  details for specimen  configuration and
  stress loading.  See TM-01-69 MACE standard
  'Laboratory Corrosion Testing of Metals for the
  Process Industry.'

• Total immersion corrosion (ASTM 483) testing
  evaluates  the general  corrosive attack of a
  cleaner  which  can   cause   unacceptable
  dimensional changes in a  metal surface.  A
  number of specifications describe variations on
  this test (MIL-C-87936. ASTM  F483).  Metal
  cleaners for aluminum and aluminum alloys can
  be evaluated in accordance with ASTM D930.
  Cleaners for all other metals can be evaluated
  using ASTM D1280.  For example, the test can
  be conducted by completely immersing a tared
  specimen into the test solution so that there is
  no air/solution interface.    The specimen  is •
  allowed to  sit undisturbed for 24 hours after
  which  it   is  removed,  rinsed,  dried,  and
  reweighed.   Corrosion  is measured  as weight
  loss.  The amount of allowable loss  should be
  predetermined  depending  on  the kind  of
  material and use. but should be restricted to a
  few milligrams.

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  22
  • Sandwich corrosion (ASTM  FI110)  testing
    measures the corrosivity of a cleaner trapped
    between fraying surfaces and then periodically
    exposed to various temperature and humidity
    conditions.

  • Hydrogen  embrittlement (ASTM   F519-77)
    testing is conducted to determine if cleaners will
    adversely affect high strength steel. Testing can
    be conducted in accordance with ASTM F519,
    using both cadmium plated and unplated Type
    1A steel specimens.   The specimens  are
    subjected to 45 percent of their ultimate tensile
    strength while immersed  in the test  solution.
    The specimens must not break for a  minimum
    of 150 hours.
 Effect on Subsequent Processes

 Since cleaning is an integral part of manufacturing
 processes, it is critical that you examine the effect
 of cleaning  on  subsequent manufacturing steps.
 These include:

 • Application of Protective Coatings.  Cleaning is
   used extensively before and after the application
   of protective and/or decorative finishes.  For
   example,  surfaces  cleaned  before painting,
   enameling, or lacquering, give better adhesion
   of finishes.  Similarly,  cleaning is used to
   remove large amounts  of oil  contamination.
   prior to electroplating.

 •  Inspection.   Inspections may  be  numerous.
   making speed and ease of pan handling very
   important. Parts are cleaned to meet customer
   requirements  and  have  to  be inspected  to
   identify any defects.

•  Assembly.  Assembly requires that parts  be free
   from inorganic and organic contaminants. The
   cleaning process should leave the parts clean
   and dry, ready for assembly, and/or subsequent
   finishing.

•  Further Metal  Working or Treatment.  In many
   instances,   pans   must  be   prepared  for
   subsequent operations such as welding, heat
   treating,  or further  machining.    Cleaning
   between steps allows the operator to start each
   new step with clean,  dry pans.  Before heat
   treatment, all traces of processing oils should be
     removed  from  the surfaces:  their presence
     causes  smoking, nonuniform hardening,  and
     heat treatment discoloration on certain metals.

  •  Machining.  By starting a machining operation
     with a  clean  surface,  the chance of carrying
     imperfect parts through to other operations is
     minimized. Cutting oils used during machining
     give best results when applied to clean surface!.

  •  Packaging.  Final cleaning  prepares  pans for
     packing and shipping.


  Process Control

  Process control  is  part of a quality assurance
  program.  Being satisfied with a  process is key to
  a  successful  program.   One  example  of good
  process  control  is  checking  cleaner  solution
  strengths on a routine basis. Maintaining solution
  strength  by making small, frequent additions is;
  much  more effective than making a few  large
  additions.
 Throughput of the Cleaning Process

 Cleaning process throughput can be an important
 parameter, especially  if  cleaning is part of a
 continuous production process.   For  example,
 adhesion of finishes can be affected by moisture
 remaining on a surface to be coated. The rapid
 drying  time  associated   with  solvent  cleaning
 provides an advantage  in speeding up production
 processes. For batch cleaning processes, this factor
 may not be critical.' Some alternative process may •
 require   .slower  throughput   for  optimized
 operations.
 Ease of New Process Installation

 Another consideration  is whether the current
 manufacturing operation is flexible enough to
 allow installation of a new process.  Would it be
 easy or would it disrupt the current process?
Floor Space Requirements

Equipment must be compatible with the plan and
space constraints of your manufacturing floor.  A

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  new process might require rearranging subsequent
  processes to optimize the floor plan.   In some
  cases, alternatives take up more space than solvent
  cleaning processes.  For example,  most aqueous
  cleaning processes include  a  drying stage  that
  requires additional  floor  space.   Rearranging
  existing equipment or installing a new process  also
  may trigger permuting requirements.
 Operating and Maintenance
 Requirements

 Each  new process will  require  operating and
 maintenance procedures.  The new process mieht
 be more cumbersome to operate and may require
 special operator training.                   j

 Maintenance  of process equipment on a reeular
 basis is critical.  For example, cleaning of spray
 nozzles is necessary to remove soil contamination
 that would make them less effective.  Pumps and
 valves should  also be checked regularly.
 Economic

 Process economics is a key factor in the selection
 of alternative processes.   Initial costs associated
 with an alternative process include capital costs of
 equipment,  possible costs associated with waste
 treatment/handling equipment and costs for permit
 changes for new construction or new  operaiing
 procedures.  In addition, operating cost  equations
 include material, labor, maintenance, and  utility
 costs. Cost estimates for an alternative process can
 be developed through preliminary process design.

 One simple  approach is to calculate net present
 value (NPV) based on the discount rate and period
 of investment your  company uses.   The NPV is
 calculated as follows, where'(n) is the number of
years, and (i) is the discount rate.
   NPV = Cost0 + Costi/(l+i) +

    Cosu/(l+i)2 + ... + Cosy(l+i)n
                                                                                               23
  While traditional economic considerations such as
  rate of return and payback period are important.
  the CFC-113 and MCF reduction program can be
  justified  on a basis of environmental protection
  and  solvent  supply  reliability.   An important
  component of the  analysis should recognize that
  the  price of CFC-113 and  MCF will increase
  rapidly as supplies are reduced and then eliminated
  and   taxes  are  imposed.    Because   of  the
  considerable   difference  in   ozone-depleting
  potential, the price increases of CFC-113 and MCF
 will vary.  Include the cost savings resulting from
 savings in solvent consumption.   Some  new
 alternative processes are much less expensive than
 the current CFC and MCF processes being used.
 Environmental, Health, and
 Safety

 Important considerations include:

 •  Compatibility with appropriate federal, Pitt, and
   local regulations. State and local regulations on
   ozone-depleting chemicals. VOCs, effluents of
   waste  ran be more stringent than their federal
   counterparts.   For example, some cities have
   taken   steps  to  phase  out  ozone-depleting
   compounds (ODCs) more quickly than the U.S.
   Clean  Air Act requires.  In addition, to the
   phaseout requirements under the Clean Air Act
   there are a number of provisions that will  go
   into effect over the next few years that will also
   impact 'the selection  of alternatives.  These
   provisions   include Section 608:    National
   Emissions  Reduction  Program.  Section  611:
   Labeling, and  Section  612:  Safe  Alternatives
   Policy.   These and other provisions must be
   considered  before selecting alternatives.

•  CompatUiiUty with regulatory trends.  Since new
   environmental policy is emphasizing pollution
   prevention  and risk reduction,  it is prudent to
   move to cleaner products and processes that are
   less  polluting, less energy-intensive,  and less
  dependent on raw materials.

> Public perceptions.  Recent legislation, such as
  "right-to-know" laws has provided  the public
  with more information about the chemicals used
  by specific  plants and their associated risks.

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24
   Public  information has  made  plants  more
   accountable  to  the concerns of neighboring
   communities.

1  Potential of alternatives for ozone  depletion and
  global  warming.   Each alternative must be
   evaluated  for  its  contribution  to   ozone
   depletion and global warming. These issues will
  be  evaluated as  pan  of the  overall  risk
  characterization  that will be conducted by EPA
  under Section 612 of the Clean Air Act.

1 Energy efficiency.  As energy costs rise,  it  is
  important to consider the energy  requirements
  of each alternative. The use of energy efficient
  alternatives  is also  desirable from a  global
  warming perspective.   Energy  issues will be
  evaluated  as   part  of  the   overall   risk
  characterization  under  Section  612:     Safe
  Alternatives Policy of the Clean Air ACL

  Effects   on  emissions,   effluents,  and   wastes
  generated.  Determine whether  environmental
  problems are eliminated or merely transferred
  from one medium to another. Each alternative
  has  differing effects on water, air. and land
  pollution. Issues such as these will be evaluated
  as pan of the overall risk characterization  that
  EPA will conduct as pan of Section 612: Safe
  Alternatives Policy of the Clean Air ACL

  VOCconcerns. In many areas, switching solvents
  can take you from an existing to a new/modified
  source,  subject  to  repermitting  and  more
  stringent controls.   Limitations  on   VOC
  emissions  may  influence  your   choice   of
  alternative.   In the U.S.. for example, certain
  states have legislation that restricts the  use of
  solvents thai are  VOCs.  Some states also  ban
  the use of substances (e.g., methylene chloride
  in New Jersey) because of possible toxic health
  effects.   Application-specific exemptions and
  containment criteria  may also CXJSL so  VOC
  regulatory provisions should be  researched
  thoroughly.   The air toxics provisions of  the
  1990  Clean Air Act  Amendments target  189
  toxic air pollutants.  Of these, 149 are organic
  compounds.

  Taacity  and Worker Safety. Alternatives should
 minimize  occupational   exposure.     The
 Occupational  Health  Safety  Administration
 (OSHA)  has  set Personal  Exposure  Limits
 (PELs)  for  many chemicals and  should be
 considered  before selecting alternatives.   In
 addition,  the   American   Conference   of
 Governmental   and   Industrial   Hygienists
 provides  threshold  limit  values (TLVs)  for
 different   chemicals.     As  pan  of   the
 implementation strategy for Section 612 of the
 Clean Air Act Amendments. EPA has  also
 initiated discussions with NIOSH, OSHA, and
 other   governmental  and   nongovernmental
 associations to develop a consensus process for
 establishing occupational exposure limits forithe
 most significant substitute chemicals.

Flammabilitv.  Fire and explosion hazards  are
very  important  considerations.     In  some
 instances  changes in process  will  have to be
brought to the attention of insurance carriers.
Flammability will  be evaluated as  pan of  the
overall  risk   characterization  that  will  be
conducted by  EPA under Section  612 of  the
Clean Air ACL

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 REVIEW OF EXISTING  PROGRAM
 Following the recommendations presented so far for developing a non-CFC-113 and MCF
 cleaning program, the following sequence of activities should be performed/carried but next:
   •  Determine where and why CFC-113 and  methyl chloroform are consumed in
      metal cleaning operations:

   •  Characterize existing cleaning processes. This activity will help you understand
      how metal cleaning integrates v/ith other manufacturing processes and determine
      whether cleaning is necessary:

   •  Characterize the soils and their sources. Identify the type of soils being removed
      and the steps to be taken to reduce the soiling of pans;

   •  Characterize the substrate materials being cleaned.  This  step will assist in
      identifying the type, shape, and geometry of materials being cleaned;

   •  Establish criteria for selecting an alternative cleaning  process.  These criteria
      include organizational, technical, environmental, health, and safety issues that
      must be considered before selecting an alternative process.
The benefits resulting from these steps include a better understanding of cleaning needs,
elimination and consolidation  of certain cleaning  operations,  and development of a
systematic procedure for selecting an alternative cleaning process.  With this understanding,
the next section describes some major alternative processes to solvent based cleaning.

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26

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                                                                         27
 ALTERNATIVE MATERIALS AND  PROCESSES
 A number of alternative cleaning processes and alternative solvents to CFC-113 and MCF
 are now available for metal cleaning operations. The choice of an alternative depends on
 cleaning needs and process selection factors.
   Alternative Cleaning Processes:

      •  Aqueous

      •  Semi-Aqueous

   Alternative Solvents:

      •  Hydrochlorofluorocarbons

      •  Aliphatic Hydrocarbons

      •  N-Methyl-2-Pyrrolidone

      •  Miscellaneous Solvents
The following sections describe the major advantages, disadvantages, and key process issues
of several alternatives.

Provision of this material in no way constitutes EPA or ICOLP recommendation or approval
of any company or specific offering. These technologies should be evaluated on a case-by-
case basis. A list of vendors and references at the end of this manual may be a useful
additional source of information.

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28
AQUEOUS  CLEANING
Aqueous cleaners use water as the primary solvent.
Synthetic detergents and surfactants are combined
with special additives such as builders. pH buffers.
inhibitors, saponifiers. emulsifiers. deflocculants.
completing agents, antifoaming agents, and other
materials. These agents provide multiple degrees
of  freedom   in   formulation,   blending,  and
concentration,  and provide  useful  synergistic
effects.   Exhibit 6 presents an  overview  of the
advantages and disadvantages of aqueous cleaning.
   The key stages of an aqueous  cleaning
   process are (see Exhibit 7):

   •   Washing

   •   Rinsing

   •   Drying

   •   Wastewater Treatment and Disposal
Although each of these steps is an important and
integral part of the aqueous cleaning process.
rinsing and  drying may  not be  necessary in all
circumstances  and wastewater disposal may be
completely integrated into other steps through the
use of recycled baths.
Process  Design and
Implementation

To  implement an  aqueous  cleaning  process,
conduct an overall evaluation of the following:

• The cleaner's effectiveness (i.e., whether it has
  good cleaning chemistry for your needs);

• The  process equipment  (i.e..  mechanical
  considerations);
Process Chemistry

Aqueous cleaners are comprised basically of three
major types of components:  (1) the builders which
make up the largest portion of the cleaner, (2) the
organic and inorganic additives which promote
better cleaning or affect-a metal's surface, and (3)
the surfactants and wetting agents.

As  we  noted  earlier,  being able to  tailor  the
cleaner formulation gives aqueous cleaning great
flexibility.    Molecular  structure,  which   has
significant effects on the properties, can be varied
over a wide range.  For example, the number of
carbons on the molecule (whether straight chain,
branched chain, or ring structure) and the ratio of
the hydrophilic  to  hydrophobic moiety can be
tailored   in   achieve  the   desired   cleaning
requirements.

Builders arc the alkaline salts in aqueous cleaners.
They  are  usually  a  blend selected  from   the
following groups: alkali metal orthophosphates and
condensed  phosphates, alkali  metal hydroxides,
silicates, carbonates, bicarbonates, and borates. A
blend of two or more of these builders is typically
used in aqueous cleaners.

Phosphates are the best overall builders. However
discharge   of  cleaning   solutions   containing
phosphates is subject to environmental regulations.
Chelating agents such as  ethylenediamine tetra
acetic  acid (EDTA) and  nitrates can  be used
instead of phosphates. Silicates are sometimes;
difficult  to  rinse  and  may cause  trouble  in
subsequent plating operations  if not completely
removed.  Carbonates and  hydroxides are cheap
sources of alkalinity and are also effective builders.

Additives  are  either organic  or  inorganic
compounds that  provide  additional  cleaning or
surface modifications.  Chemical compounds such
as glycols.  glycol ethers, chelating  agents, and
polyvalent  metal  salts,  could be  considered!
add'itives.   Some of  these  materials  could  be:
subject to VOC concerns.
• Other process  characteristics  (e.g., wetting
  agents).

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                                                                                                                 23
                                                 Exhibit 6
                                    AQUEOUS  CLEANING
 ADVANTAGES

 Aqueous cleaning has several advantages over organic
 solvent cleaning.

      Safety - Aqueous systems have few problems with
      worker safety compared to many solvents. They are
      not flammable or explosive. Consult material safety
      data sheets for information on health and safety.

 •     Cleaning - Aqueous systems can  be designed to
      clean panicles ana films better than solvents.

 •     Multiple Degrees-oi-Freedom ~ Aaueous systems
      have multiple dezrces   Wastewater Disposal - In some instances use of aqueous
   cleaning may require wastewater treatment prior  to
   discharge.
i

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30
                             Exhibit 7

  CONFIGURATION OF AQUEOUS CLEANING PROCESS
            IN THE METAL CLEANING INDUSTRY
       Parts from
      Manufacturing
        Process
                 Wash
                 Stag*:
               Heated Detergent
               Solution: Spray.
               Immersion
               Ultrasonics, etc.
   Rinse
   Stage:

   Water:
Spray, immersion
  Dryer:

Room Temp Air
or Heated Air
Cleaned
Parts Ready
for Continued
Production
        Solution
     Reeirculation:
  Pillaring, Skimming
                   Periodic Removal
                Waste Treatment
 Source: EPAl989a

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                                                                                                  3t
 Surfactants are organic compounds that provide
 detergency, emulsification. and wetting in alkaline
 cleaners. Surfactants are unique because of their
 characteristic chemical structure.  They have two
 distinct structural components attached together as
 a single molecule.  A hydrophobic half has little
 attraction for the solvent (water) and is insoluble.
 The other half is hydrophilic and is polar, having
 a strong attraction  for the solvent (water) which
 carries the molecule into solution.  Their unique
 chemical structure provides high affinity for surface
 adsorption.  Surfactants are classified as anionic.
 canonic, nonionic, and zwitterionic (amphoteric).
 Surfactants  most useful in metal  cleaning are
 anionic and  nonionic.                     \

 In spray wash alkaline cleaning virtually zero foam
 can be tolerated, therefore, surfactants must  be
 selected   that  do not  foam under  the  selected
 process conditions.

 Nonionic surfactant  is generally the only type that
 results in minimum foaming and provides good
 detergency.  For immersion  cleaning all  types of
 surfactants can be used; however, in most cases the
 anionic or nonionic  type are used.
Process Equipment

Aqueous cleaning equipment can be characterized
as:

•  In-line equipment for high throughput cleaning
   requirements;                           !

•  Batch equipment for low throughput, such as
   maintenance applications or small production
   processes.

The in-line and batch equipment can be further
subdivided into immersion, spray, and ultrasonic
equipment.  Exhibit 8 presents an overview of the
advantages and disadvantages of these three types
of equipment.

Immersion equipment cleans the parts by immersing
them in a  solution  and  using some  form of
agitation to add the energy needed to displace; and
float away contaminants. Soil is removed from the
metal  surface  by  convection  currents  in  the
 solution, the currents are created by heating coils
 or by some mechanical action.

 Spray  equipment  cleans  parts with  a solution
 sprayed  at   medium-to-high  pressure.    Spray
 pressure can vary from as low as 2 psi to 400 psi or
 more.  In general, the higher the spray pressure,
 the more mechanical help is provided in removing
 soil  from metal  surfaces.  Spray cleaners  are
 prepared with low foaming detergents which are
 not  as chemically effective as  those used  in
 immersion cleaners, but are still effective because
 of the mechanical agitation.

 Although spray cleaning is effective on most parts,
 certain ran figurations such  as the interior of an
 automobile tail pipe  have soiled areas that are
 inaccessible to the sprayed cleaning solution.  In
 these instances, immcrsinn cleaners  are  more
 effective.

 A high pressure spray is an effective final rinse
 step.  Pressures may range  from 100 psi in less
 critical applications to 500 psi or even 2000 psi in
 critical applications. Optimization of nozzle design
 such as spray pattern, drop size  and formation,
 pressureArclotity, and volume are very important
 and have a major impact on effectiveness. A final
 spray is much cleaner than an immersion bath,
 since the final water touching the pan can be
 highly pure and filtered.

 Ultrasonics equipment works  well with water-based
 processes.   Because  the  captation efficiency  is
 high, the removal  of panicles  from  surfaces  is
 usually more  effective in  aqueous versus organic
 solvent media. Ultrasonic cavitation efficiency is
 typically lass effective in CFCs and MCF than with
 water-based chemistry.  Process design requires
 caution to insure that cavitation erosion of pan
 surfaces is not a problem.  Certain pan geometries
 are also ultrasonic sensitive.

 It  is  important   to  optimize  your  system's
 capabilities when using ultrasonic systems.  Since
 good ultrasonic cleaners have few standing waves,
 reflection from the surface and the walls is an
 important consideration. The number of pans and
 their  orientation  is  very  important  for  good
cleaning.  The fixturing should be low mass, low
surface   energy,  a'nd  nonabsorbing  cavitation
resistant material such as a stainless  steel wire
frame. Avoid using plastics for fixtures  because of

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32
     IMMERSION WITH
       ULTRASONIC
        AGITATION
                                     Exhibit 8

              AQUEOUS CLEANING PROCESS EQUIPMENT
      IMMERSION
  WITH MECHANICAL
      AGITATION
                                                            SPRAY WASHER
   ADVANTAGES
   Highest level of
   cleaning; cleans complex
   parts/ configurations

   Can be automated

   Usable with pans on
   trays

   Low maintenance
 Usable with parts on
 trays

 Will flush out chips

 Simple to operate

 Cleans complex parts
 and configurations

 Can use existing vapor
 degreasing equipment
 with some simple
 engineering changes.
 High level of cleanliness

 Inexpensive

 Will flush out chips

 Simple to operate

 High volume

 Portable

 Short lead time
   DISADVANTAGES
   Highest cost

   Requires rinse water for
   some applications

   Requires new basket
   design

   Long lead time

   Can't handle heavy oils

   Limits part size and tank
  volumes

  May require separate
  dryer
Requires rinse water for
some applications

Harder to automate

Requires proper part
orientation and/or
changes while in solution

May require separate
dryer
Requires rinse water for
some applications to
prevent film residues

Not effective in cleaning
complex parts

May require separate
dryer

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                                                                                                33
leaching and absorption of sonic energy. It is also
important to optimize the size of the load to the
size of the  tank.   Both  ultrasonic and  spray
equipment  can .be  used  to  great -advantage,
especially in rinsing.  There are benefits for both
immersion ultrasonics and spray using high-puriry
water. Low pressure (40-80 psi) at relatively high
volumes is good for initial rinsing.  It is critical to
keep the pan wet at all times prior to final drying.
The spray design should be able to reach all pan
surfaces by mechanically manipulating the pan or
the spray nozzles.    A  secondary  immersion-
ultrasonic rinse is especially useful for pans with
complex geometry or holes.

In some instances final rinsing with DI water or an
alcohol, such as isopropanol. can remove residues
and prevent water spots.
Other Process Considerations

Product design can have a significant influence on
cieanability.  The choice of materials and  pan
configuration should be reviewed for opportunities
to make changes that have a major influence on
the success of water-based cleaning.

Care should be  taken to prevent cleaning fluids
from being trapped in holes and capillary spaces.
Low surface tension cleaners sometimes penetrate
spaces and are not easily displaced by a higher
surface tension, pure water rinse. Penetration into
small  spaces is a function of both surface tension
and capillary forces.

Water-based cleaning is sometimes not as forgiving
as CFC-113 and MCF cleaning. Good engineering
and process control are more critical in preventing
problems.  Useful parameters for process control
include bath temperatures.  pH, agitation,  rinse
water  quality, and  cleaning bath  quality.   Pan
inspection  by a  method such as contact angle,
turbidity,  or ASTM  F24  can  be very useful.
Valuable bath and water quality  measurements
could  include  conductivity/resistivity,  particle
count, turbidity, and TOC (total organic carbon).

Drying presents  the   major  challenge  when
switching to aqueous cleaning.  For simple parts,
this obstacle may be minimal, but for complex
parts drying may require considerable engineering
 and experimentation. Solvent equipment that is
 currently in use has no real provision for drying:
 the  thermodynamics of CFC-113 and MCF are
 favorable to spontaneous evaporation.

 Aqueous cleaning requires careful consideration of
 drying materials.  Evaporative removal  of  bulk
 water is usually not practical from the perspective
 of energy use or process time.  Compact turbine
 blowers  with  filtered outputs can  mechanically
 remove 90 percent or more of the water.  Design
 options in blowers  include variation of pressure.
 velocity, and volume flow.  Other sources of air
 include dedicated compressors or plant ain great
 care must he taken to assure desired air quality by
 appropriate  filtration  of  oil.  panicles,  and
 moisture.  When using  such options, economics
 and  noise reduction are  other  considerations.
 Humidity sind air conditioning control,  and the
 associated economics, may be an issue for the
 equipment and the plant.

 Evaporative drying  following mechanical water
 removal   can  be  accomplished using   infrared
 heating,   clean  dry  air-heated  or   at  ambient
 temperature, or vacuum heated drying. Dryers can
 be designed, for either in-line or batch operations.
 Drying  design  should always be confirmed by
 experimentation.

 Wastewater  treatment   and  recycling   is  an
 important consideration.  Some detergents and
 surfactants are biodegradable, while others are not.
 In many applications the cleaning bath is changed
 infrequently  and a relatively low volume of
 wastewater is discharged.  In others, the water can
 be evaporated to leave  only a small volume of
 concentrated waste for recycling.

 Recycling or regeneration of the cleaner/detergent
solution is feasible and should be considered. .This
can be accomplished using a combination of oil
skimming techniques, coalescing separators, and
ultrafiltration (ceramic membranes).

Details on wastewater treatment and recycling are '
presented later in this manual

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   34
   SEMI-AQUEOUS
   CLEANING
  Hydrocarbon/surfactant  cleaners  are  emulsion
  cleaners that can be substitutes for CFC-113 and
  MCFin metal cleaning applications.  Hydrocarbon/
  surfactants have been included in many different
  cleaners formulated for different purposes. Hydro-
  carbon/surfactants are used in cleaning processes in
  two ways.  They are  either emulsified in water
  solutions  and applied in a manner similar to
  standard aqueous cleaners or they are applied in
  concentrated form and then rinsed with water.
  Because both methods use water in the cleaning
  process, the hydrocarbon/surfactant based process
  is commonly known as a semi-aqueous process (see
  Exhibit 9).


  Advantages

  The advantages of semi-aqueous cleaning solutions
  include the following:

  • Good cleaning  ability especially for  heavy
   grease, tar, waxes, and hard to remove soils:

  • Compatible with most metals and plastics:

  • Suppressed vapor pressure (especially if used in
   emulsified form);

 • Non-alkalinity  of process  prevents etchine of
   metals thus helping to keep metals out ofthe
   waste streams:

 • Reduced evaporative loss;

 • Potential decrease in solvent purchase cost;

 • A rust  inhibitor  can  be included  in the
   formulation to protect parts from rusting.
  •  Recycling or disposal cost of wastewater could
    make the process less economically viable;

  •  Flammabiliry concerns if a concentrated cleaner
    is  used  in spray  cleaners.    However, the
    flammability issue can be solved  with proper
    equipment design;

 •  Some cleaners have objectionable odors;

 •  Some of the cleaners are VOCs;

 •  Drying equipment may be required in some
    applications; and

 •  Some cleaners can auto-oxidize. For example,
   d-limonene (a type of terpene) can auto-oxidize
   from contact with air.  This  can  be reduced
   using an antioxidant additive.
Cleaning  Process

The  steps  in a typical  semi-aqueous  cleaning
process  are analogous to aqueous applications.
Equipment for use with semi-aqueous processes is
also  similar  to aqueous  cleaning  equipment
designs.
Disadvantages

The disadvantages include:
   The four major steps used in the cleaning
   process are:

   •   Wash  step  with  a  hydrocarbon/
      surfactant;

   •   Rinse step with water;

   •   Drying  process  .to  remove  excess
      water

   •   Wastewater disposal.
• Rinsability problems, because residues can be
  left;

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                   Exhibit 9
      SEMI-AQUEOUS PROCESS FOR
 IMMISCIBLE HYDROCARBON SOLVENT
Hydro carton/
 Surfactant
 Wash Stag*
Emulsion
 Rlnst*
Rinu
  Dryer
Forced Hot Air
Hydro caroon/
 Surfactant

  RMIM
 Dispose or
 R*cycJซ
                                          Clsamd
                                          Parts
                                         TrMtmtntor

                                        T)DUปettoOrซin
                 Decanter

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   36
   In cases where extreme cleanliness is required, the
   hydrocarbon/surfactant cleaning can be followed by
   a fiilly  aqueous  wash  step "with an  alkaline
   detergent and a deionized water  rinse.   AS in
   aqueous cleaning, it is important to note that both
   the  wash and the  rinse stage are recirculating;
   these solutions are not continuously discharged.

   In  the wash step, the  hydrocarbon/Surfactant
   cleaner is applied to the pan being cleaned with
   some form of mechanical energy.. Low flash point
   hydrocarbon/surfactant cleaners are generally not
   heated: however, some are slightly warmed when
   the cleaner is used in a diluted form.  High flash
  point  hydrocarbon/surfactant  cleaners  may be
  heated to  within 20-30ฐF of their  flash point to
  remove difficult soils.  Cleaners that are ignitable
  should not be used  in vapor or spray cleanine
  without an inert atmosphere or other protective
  equipment.    Application  methods  that  a%-oid
  misting such as spray-under immersion, spin-under
  immersion, or ultrasonics should be used. Dilute
  hydrocarbon  emulsion  cleaners  formulated with
  water may be heated.  Less mechanical energy is
  needed  when using  a  hydrocarbon/Surfactant
  solution than  when using an  aqueous  solution
  because of the  high solvency of  hydrocarbon/
  surfactant cleaners.

  A rinse with clean water removes the residues left
  by the wash step.  The rinse step is necessary when
  concentrated hydrocarbon/ surfactant cleaners are
  used because of their low volatility (which prevent
  them  from  evaporating from the "parts cleaned in
 the wash stage).   The rinse  step  may not be
 necessary when a dilute hydrocarbon/surfactant
 emulsion is used, if the level of cleanliness needed
 does not require removal of the residue from the
 wash stage.  In some instances, alcohol is used as
 a final rinse step. The rinse step may also serve as
 a finishing process and in some instances is used to
 apply  rust inhibitors to the parts.

 The drying step serves the same function as it does
 in aqueous  cleaning.  The  removal of remaining
 water  from  the  part prepares  it  for  further
 processing or prevents it  from rusting. Heated or
 high velocity   room  temperature  air  are  the
 principal drying agents.   As in aqueous cleaning
 the drying step may not be needed if the parts are
 rust inhibited, are not immediately needed, and/or
are moved immediately to another wet process.
   The  wastewater  disposal  step  is  always  an
   important part of the cleaning  process.  As  in
   aqueous cleaning most of the contaminants in the
   wastewater are removed by decanters and filters as
   the solution is recirculated in the tank.

   Some available hydrocarbon/surfactant cleaners cam
   be easily separated  from the rinse  water.  This
   allows the rinse water to be recycled  or reused.
   The waste  hydrocarbon/surfactant  can  then  be
   burned as fuel.  In such cases, contaminants, like
   oil and  grease, removed  from  the pan being
   cleaned are retained in the hydrocarbon^urfactanit
   phase, thereby greatly reducing the contamination
   loading in the water effluent.
  Process Equipment

  Equipment for use specifically with concentrated
  hydrocarbon/surfactants  is  available.   As with
  aqueous cleaning, this equipment can be classified
  as immersion or spray equipment, either batch or
  in-line equipment.

  Immersion equipment is the simplest design used
  in hydrocarbon/surfactant-based cleaning.   The
  immersion equipment works with but is not limited
  to the dilute emulsion solutions which do not
  present the combustion (flammability) danger  of
  the concentrated hydrocarbon/ surfactants.  These
  pieces of equipment may operate in batch or in-
  line  configuration.     Certain  solvent  vapor
 degreasers can be retrofitted to allow immersing of
 the parts into the bath of emulsion cleaner. The
 parts are simply dipped into the bath  which may or ••
 may not be heated. Because of the solvency of the
 hydrocarbon/ 'surfactants, little mechanical energy
 needs to be added to achieve adequate cleanliness.
 Higher cleanliness can  be achieved by adding
 agitation  to  the process, either mechanically or
 with  ultrasonics,  or by heating the cleaning
 solution.

 As with aqueous  cleaning, a mechanical  spray
 improves the cleaning performance of the solution.
 When using concentrated hydrocarbon/surfactants,
 the atomized solution is prone to combustion and
special care must be taken to prevent it  Nitrogen
blanketing displaces  oxygen  from  the spray
chamber which is enclosed to prevent  sparks from
entering.

-------
When using concentrated hydrocarbon/surfactant in
immersion  equipment, 'spray-under  immersion*
can  be performed.   In  this equipment,  high
pressure spray nozzles are placed below the surface
of the liquid.  This prevents the formation of
atomized solution  and decreases flammability.
Mechanical agitation, workpiece movement, and at
properly designed ultrasonic agitation may also be
used.

-------
   38
   HYDROCHLOROFLUORO-
   CARBONS

   Several HCFCs (e.g., HCFC-225ca. HCFC-225cb.
   HCFC-141b, and HCFC-123) have been proposed
   as possible CFC-113 and MCF substitutes. Exhibit
   10 presents physical properties of these chemicals.
     There are several issues to iceep in mind
     as you make your decision:

     •   HCFCs' have  an  ozone-depletine
         potential (OOP);  while  the OOP is
         significantly lower  than  CFC-113.
         HCFCs are subject  to  production
         control requirements imposed by the
         Clean Air Act Amendments of 1990.
         and are targeted for phaseout by 2030.

     •    HCFCs are also subject  to Section
        608:  National  Emissions Reduction
        Program   that  will  set   Lowest
        Achievable  Emission Levels (LAEL)
        for HCFCs, Section  611:  Labeling
        that  will  require  labeling of  all
        products   manufactured   with   or
        containing HCFCs. and Section 612:
        Safe  Alternatives  Policy  that  will
        conduct overall risk characterization
        and set occupational exposure limits
        for the use of HCFCs.

    •  Some HCFCs are currently available
       only in limited quantities for customer
       evaluation: commercial production is
       expected soon.

       These  solvents have  good cleaning
       performance.
Blends of  different HCFCs  are also  possible.
Several companies have now developed constant
boiling blends of HCFC-123  and HCFC-14ib.
These solvent blends are an acceptable alternative
to CFC-113 and MCF for removing heavy grease
and water-soluble oil residues. They are equivalent
   to CFC-113 and MCF for removing light oils, but
   far less effective for buffing compounds.

   If you choose blends.as an alternative to CFC-113
   and MCF, it is important to consider  possible
   process design changes. For example, conventional
   degreasers   require   modification   to   extend
   freeboards and lower condenser temperatures.  In
   addition, provisions such as superheated-vapor
   drying or increased dwell  times in  freeboard are
   desirable to reduce dragout  losses and can be
   incorporated into the design.

  The  high volatility of  HCFC cleaning solutions
  require special  equipment design  criteria.   In
  addition, the economic use of HCFCs may require
  special emission  control  features  for  vapor
  degreasers  (see  Exhibit lla.  b, and  c).   These
  include:

  • Automated work transport facilities:

  • Hoods and/or automated covers on top entry-
    machines:

  • Facilities  for  work  handling that minimize
    solvent entrapment:

  •  Facilities for superheated vapor drying;

  •  Freeboard deepened to width ratios of 1.0 to
    2.0;

 •  Main condenser operating at 458 to 55"F;

 •  Secondary condenser operating at -30ฐ to -20ฐF;

 •  Dehumidification condenser operating at -30 to
   -20ฐF (optional);

 • Seals and gaskets of chemically  compatible
   materials;

 •  Stainless steel construction: •

 •  Welded piping containing a minimum of flanged
   joints:

•  A gasketed  water separator or  refrigerated
   desiceam dryer for methanol blends;

•  A cool room to work in is  recommended;

-------
•  Controlled exhaust from  refrigeration unit to
   prevent  excessive  heat  from  reaching the
   separator chambers.

Material  compatibility  is  another  important
consideration.  The HCFC-123/HCFC-141b blends
require compatibility testing with magnesium, zinc
and other metals. In addition, the solvent blends
have shown some adverse effects with plastics such
as ABS, acrylic, and  Hi-Impact  Styfene.  lake
metals, plastics need to be tested on an individual
basis.

-------
40
                                Exhibit 10
                 PHYSICAL PROPERTIES OF HCFCs
                  AND OTHER SOLVENT BLENDS
                CFC-I13
MCF
                        HCFC-Wlb/1
                        HCFC-123/
HCFC-225ca    HCFC-225cb    MethanoJ
Chemical Formula
Ozone Deleting
Potential
Boiling Point <*C)
Vi5coซrty (cpa)
Surface Tension
(dyne/cm)
Kauri-ButanoJ
Value
Flath Point *C
Toricfty
CCtjFCCIFj CHjCCL, CFjCFjCHCL^
0.8 o.l -0.05
47-6 73.9 Si.i
0-68 0.79 0.59
17.3 25.56 16.3
31 124 34
None None None
Low Low Underway .
CC!F2CF2CHCIF
-005
56.1
0.61
17.7
30
None
Underway
CF CC1~H/
CH33OH
0.0&0.13
29.8
0.47
18.3
76
None
Near Completion
          w               at 'X"t Ch-"niC" "*"ซปซ"ซ"• recommend., blend of HCFC-Ulb/HCFC-
                      *" "" •r*Ctrop- ฐ* HCFC-141 b/HCFC-123/methanollor .emFtynthrtc and •ymhette
 o.

-------
                                                              41
                          Exhibit 11 a

       ADVANCED DESIGN DEGREASER FOR
    USE WITH LOW BOILING POINT SOLVENTS
     Hooded Work Transporter on Open-Top Degreaser
Hood
       ii   il
                Work Transporter
Source: DuPont
                        .Additional
                         Freeboard
, Diffusion
Control
Coll -20*F
                                 Free-
                                 board
                                 Depth
                       ฃ2.
  # t •
                                                   Dehumidifier Coll
                                                   -20ฐ F
J
                                      Main
                                     Condensor
                                     40"-50eF
                                           Dry
                                         Chamber
                                         iiiiii.
                                    Heating
                                    Coil
                                                           S16060-4
                                                                  S16I

-------
42
                            Exhibit lib

      STACKED LOW EMISSION DEGREASER WITH
               SOLVENT SAVING FEATURES
            Closing Lid
            Refrigerated
             Freeboard
            Inter Coil _
              Baffle
            Four Sided
             Cascade
            Condensing

o
o
o
21

Free
•- Board

F.B.R. = 1

o
o
o
li
           Convection
            Current
             Break
            Standby
            Mode

            Defrost
            Trough
                         X '//////////////.
  Source: ICI
Solvent Saving
Features
(not shown)

Screwed pipe joints
Correct sealing material
Correct pump seals .-..
Minimum number of
  pipe joints
Degreaser enclosure
Mechanical handling with
  optional rotation
Correct size basket
                                                             tistat-i

-------
                         Exhibit lie

        ADVANCED DESIGN DEGREASER FOR
     USE WITH LOW BOILING POINT SOLVENTS
  Tumed-ln
 Anti-Diffusion
    Lip
  Vapor Trap
  (optional in
 many cases)
-20ฐ F to-40ฐ F

Main Condensor
   35ฐ F
Vapor Generator
    Sump
                Heating Elements

 'Machine Width = w; w = 1 indicates 100% Freeboard
  Source: Allied-Signal
Gasketed
Desiccant
Dryer with
 P-Trap
                                     Freeboard
                                     Depth = 1'
                                                    Rinse Sump
                                                         115151-J

-------
 44
 N-METHYL-2-
 PYRROLIDONE
 N-Methyl-2-Pyrrolidone. also referred  to as M-
 Pyrola> or NMP is miscible with water and  most
 other organic  solvents  including  esters, ethers,
 alcohols,  ketones.  aromatic  and  chlorinated
 hydrocarbons, and vegetable oils.  It has powerful
 solvent  properties as evidenced  by its physio-
 chemical properties.  These properties  include a
 solubility parameter of 11.0. high purity,  hieh  flash
 point, and low volatility.

Testing of NMP for specific cleaning applications
is underway.  Initial results indicate that NMP is
         effective in ultrasonics applications and cavitates at
         both room temperature and elevated temperatures
         in its 100 percent active form.  Metal substrates
         that have  been successfully tested  with  NMP
         include carbon steels, stainless steel 304, 316, 317,
         Carpenter 20CB3 Admiralty brass, Cupro-Nickel
         and ferralium. Several polymeric materials such as
         Epoxy-Urethane are sensitive to NMP. Exhibit 13
         summarizes the solvent's  principal  properties.
         Exhibit  12  shows two typical process equipment
         designs  that have been used successfully for both
         batch and in-line operations.
                                       Exhibit 12

                         SUMMARY OF  PROPERTIES
                       OF N-METHYL-2-PYRROLIDONE
   Empirical Formula
   Molecular Weight
   Freezing Point
   Boiling Point
   Vapor Pressure (20ฐC)
   Viscosity (25"C)
   Specific Gravity
   Interfadal Surface Tension (25ฐC)
   Flash Point (open cup)
             (closed cup)
   Explosive limits
  Heat of Combustion
  Specific Heat
  Heat of Vaporization
  Miscibility with Other Solvents
  Source:  GAP Chemical
 99.1
 -24.4ฐC (-11.9ฐF)
 202ฐC (395ฐF) @ 760 mm
• 0.29 mm
 1.65 cp
 1.027
 40.7 dynes/cm
 95ฐC (204ฐF)
 93ฐC (199ฐF)
 0.058 grams/filter - lower limit
 2.18% vapor in air - JWF (182ฐC)
0323 grams/liter - upper limit
 1234% vapors in air - 370ฐF (188ฐQ
719 K cai/mol
0.40 K cal/kg at 20ฐC
1273 K cal/kg (230 BTU/lb)
Completely miscible  with water and  most organic
solvents including alcohols, ethers, ketones, aromatic
and chlorinated hydrocarbons and vegetable oils.

-------
                                  Exhibit 13

                  NMP CLEANING  PROCESSES
          Cleaning Tank
           { 1-3 min.;
             NMP
        Ambient to 180 ฐF.
         20 to 30 Psig.
                             SPRAY WASH CLEANING
     (Spray under immersion recommended.)

               Rinse Tanks
          1 mm.
30 sec. ']
              Daionized Water.
                120ฐF.12Psig
                 Drying
                                                                 Forced
                                                                 Hot Air
                                                                   or
                                                               • Vacuum.
                            IMMERSION TANK CLEANING
            . Cleaning Tanks
      WrWVWV
         1-3 min..
      WrWWW
rWrWrWV
WrWVWr
                 NMP
            Ambient to 180ฐ F.
         With or without Ultrasonics
                      Rinse Tanks
                  1 min.
      1 min;
                     Deionized Water.
                        200ฐ F.
                    Drying
 Slow Pullฎ
or Capillary
 Drying.
Forced Hot
   Air.
     0 May be spray rinsed.
     ฉ Slew incremental removal from Ol water.
       Effective on flat surfaces.
Source: GAP Chemicals Corporation
                                                         nstn-4

-------
 46
 ALIPHATIC
 HYDROCARBONS
 There is a wide range of aliphatic hydrocarbon
 solvents that can be used in metal cleaning (see
 Exhibit  14).    Petroleum fractions,  commonly
 known as mineral spirits or kerosene, are used
 extensively in  maintenance cleaning  (e.g., auto
 repair).  These operations are single stage, open
 top processes using ambient air drying.  In most
 cases such processes are not suitable for original
 equipment manufacturing cleaning.    Synthetic
 aliphatic hydrocarbons, which offer closer control
 of composition, odor, boiling range, evaporation
 rate, etc.. are employed in OEM cleaning processes
 and will be discussed below.

 The advantages of aliphatic hydrocarbon cleaners
 include:

 •  Good cleaning ability for a wide variety of soils,
   especially heavy grease, tar, waxes and hard to
   remove soils. Low surface tension allows good
   penetration.

 •  Compatible (non-corrosive) with most rubbers,
   plastics and metals.

 •  They employ no water, hence can clean water
   sensitive parts.

 •  Low odor and low toricity grades available.

 •  Reduced evaporative loss.

 •  No wastewater stream.

 •  Recyclable by distillation.  High stability and
   recovery.

The disadvantages include:

 •  Flammability concerns.    However,   these
   concerns can  be  mitigated  with  proper
   equipment design.

•  Slower drying times than halogenated solvents.

•  VOC  control may be required.   However,
   equipment, such  as  carbon  adsorption and
    condensers,  exist  to  recover  solvent  from
    effluent air.

 •  Some grades have  low Occupational Exposure
    Limits.

 The steps in a typical hydrocarbon cleaning process
 are  analogous to  aqueous  or  semi-aqueous
 processes.  Equipment designs for use with hydro-
 carbons arc modified aqueous equipment designs.

 The  major steps  in  the  cleaning  process are
 typically:

 •  Wash steps (1 to 3  stages depending on degree
    of cleaning needed) with a hydrocarbon cleaner;

 •  Drying sicp. using forced air;

 •  VOC recovery  from  sc-venr  laden  air,  if
    required: and

 •  Waste solvent recovery or disposal.

 The wash steps involve liquid-phase cleaning at
 temperatures sufficiently below the flash point of
 the fluid. Ultrasonics or other agitation processes
 such as immersion spraying, parts rotation or fluid
 pumparound can be  used to  augment cleaning
 action.  Spraying or misting processes, where fine
 droplets arc formed, should be employed only in
 an inert environment or with equipment with other
 protection  against  ignition conditions.    This
 protection is required because fine droplets can
 ignite at temperatures below bulk fluid flash point

 Fluids with flash points near 40ฐC (104ฐF) should
 be  operated in unheated equipment, at ambient
 temperatures.  For higher flash points, hot clean-
 ing can be employed to boost cleaning action. For
 systems with good temperature control (indepen-
 dent temperature sensors, cutouts, level indicators,
 etc.), a safety margin of  15ฐC (27ฐF) between the
 fluid flash point and the cleaning temperature is
 recommended.  For systems with poorer tempera-
 ture control, a larger margin should be employed.

 Each  wash  step should  be followed  by a drain
 period, preferably with  parts rotation, to minimjfcc
solvent dragout from stage to stage.

 In multistage processes, fluid from one bath is
periodically transferred to the preceding bath as its

-------
                                                                                             47
soil level builds up. Fresh solvent is added only to
the final bath to ensure the highest cleanliness of
parts, and spent solvent is removed only from the
first stage.

The drying step  normally uses forced air, which
may be heated. Either the dryer should operate at
15ฐC  below  the flash  point  of  the  fluid, or
sufficient air flow should be provided so that the
effluent air composition is well below the Lower
Explosive Limit of the system.

The VOC recovery step is an important part of the
cleaning process.  Depending on the solvent
chosen, either carbon adsorption or condensation
are the best  technologies for recovering solvent
vapors from  spent drying air and lip vent air.
Numerous vendors market this type of recovery
equipment.

In the waste  recovery area, the best reclamation.
technology for these products is usually filtration
and distillation.  One of the advantages of the low
olefin content and narrow distillation range is that
the recovery in distillation is  high.  Should some
disposal of residual  solvent  be  necessary, fuel
substitution or incineration are good routes.
                                           'Exhibit 14

                    PROPERTIES OF ALIPHATIC SOLVENTS
PRODUCT
Mineral Spirits
Odorless Mineral Spirits
140 Solvent
C10/C11 Isoparaffin
C13 N-Paraffin
C10 Cycloparatfin
Kerosene
Lb./GaJ.
60ปF
6.37
6.33
6.54
6.25
6,35
6.75
6.60
Sp. Gf.
60'/60*F
0.764
0.760
0.786
0.750
0.760
0.810
0.790
Boiling
Range "F
305-395
350-395
360-410
320-340
320-340
330-360
330-495
Fi. R.
•FTCC
105
128
140
107
200
105
130
KB
32
27
30
29
22
54
30
Evap.
Rate1
0.1
0.1
0.1
0.3
0.1
0.2
-
1 n-Butyl Acetates 1

Note:
KB = Kauri Butanol Value
Fl. Pt. = Flash Point

-------
  48
  MISCELLANEOUS
  SOLVENTS


  The metal finishing industry has used a wide ranee
  of solvents for cleaning.  Some of the solvents.
  commonly used, include:

  •  Ketones:

  •  Alcohols;

  •  Glycol Ethers:

  •  Esters; and

  •  Other chlorinated solvents.
 The ketones form a  group of very  powerful
 solvents (see Exhibit 15a). In particular, acetone
 (dimethyl  ketone)  and ethyl methyl ketone are
 good solvents  for  polymers  and adhesives.  In
 addition, acetone is an efficient dewatering agent.
 However, their flammability (note that acetone has
 a flash point of 0ฐF) and incompatibility with many
 structural  polymers  (e.g.,  stress  cracking  of
 poh/ether   sulphone,   polyether  ketone,   and
 polycarbonate) means that they should only be
 used with care and  in small quantities.

 Alcohols such as ethanol, isopropanol, and several
 glycol ethers are used for a number of applications.
 These solvents are  chosen for their high polarity
 and for their effective solvent power. The alcohols
 have a range of flash points and care  must be
 exercised while using the lower flash point alcohols
 (see Exhibit  15b).   Solvents  in  this  family,
 particularly certain glycol  ethers,  can  cause
 swelling, cracking,  and structural degradation of
 polymeric and elastomeric materials.

 Esters, such as dibasic esters and aliphatic mono
 esters, have good solvent properties.  They offer
 good cleaning for a variety of grimes and soils.
 Most of these  materials are readily soluble in
 alcohols,  ketones, ethers, and hydrocarbons, but
 are only slightly soluble in water.  Dibasic esters
 have high  flash  point  and low vapor pressure.
They are only slightly soluble in high paraffinic
hydrocarbons. Dibasic esters are so Tow in vapor
  pressure that  a residual film will remain on  a
  surface  after   application.    Aliphatic  esters,
  generally acetates, range in formula from ethyl
  acetate to  tridecyl acetate.  The higher grades
  (hexyl acetate and heavier) are commonly used in
  degreasing. They fall into the combustible or non-
  combustible flash point  range.    They  have
  acceptable  compatibility with  most  polymers.
  These esters can be dried from a surface by forced
  air drying with no residual film.

  Other   chlorinated  solvents   such   as
  trichloroethylene,   perchloroethylene,  and.
 methylene chloride also are effective cleaners.
 However, trichloroethylene and perchloroethylene
 have  been  shown  to  exhibit  photochemical
 reactivity and are regulated as smog precursors.
 These  substances also have  been shown to  be
 carcinogenic to animals, and care should be taken
 in  their use. Chlorinated solvents  are subject to
 hazardous waste  regulations under the  Resource
 Conservation and Recovery Act (RCRA).  Users
 of  these solvents must be aware of and  comply
 with  all  federal, state,  and  local  regulations
 governing use.  storage,  and disposal  of these
 materials.   In  addition  to being classified  as
 hazardous waste, these solvents are subject  to
 reporting  requirements  under  the  Superfund
 Amendments and Reauthorization Act (SARA)
 Title  III.  Occupational exposure standards have
 also been set for the  use of these solvents and
 must   be  considered   when  selecting   these
 alternatives.     Chlorinated  solvents  might  be
 selected substitutes for CFC-113 and MCF in some
 cases.  Recent developments in emission control
 technology as  described  in  the  discussion of
 HCFCs, might  mitigate  some effects  of these
substances. Exhibit 16 summarizes the properties
of these other chlorinated solvents.

-------
                                                                          49
                                  .Exhibit 15a



                        PROPERTIES OF KETOMES
KETONES
ACETONE
METHYL ETHYL KETONE
DIETHYL KETONE
METHYL n-PROPYL KETONE
CYCLOHEXANONE
METHYL ISOBUTYL KETONE
METHYL n-BUTYL KETONE
METHYL CYCLOHEXANONE
(Mixed Isomers)
ACETONYL ACETONE
DIISOPROPYL KETONE
METHYL n-AMYL KETONE
OIACETONE
Formula
CH3COCH,
Cr^COCsK,
C^CCCjH,
CHjCOCjlV
(CH,)SCO
(CHj)2CHCH.COCH,
CH-jCOCjH,
(CH3)C5H9CO
CHjCOCjH^OCH,
(CHj)2CHCOCH{CH,)2
CKsfCHj^COCH.,
(CH3)2C(OH)CH2COCH,
Mol. Wl.
58.08
72.10
86.13
86.13
98.14
100.16
100.16
11ฃ17
114.14
114.18
114.18
116.16
lbป
per
gal
6.58
6.71
6.80
6.72
7.88
6.68
6.83
7.67
8.10
6.73
6.81
7.82
B.P.
•f
132-134
174-177
212-219
214-225
266-343
234-244
237-279
237-343
365-353
237-2151
297-309
266-336
P.P.
•F
-138.6
•123.5
•43.5
•108.0
-49.0
-120.5
-70.4
-
15.8
-
-31.9
-65.2
Evap
Rate
CCI4
-100
139
97
.
66
12
47
32
7
1
-
15
4
Coefficient
of
Expansion
Per *F
0.00080
0.00076
0.00069
0.00062
0.00051
0.00063
0.00055
0.00042
0.00052
.
0.00057
0.00055
Surface
Tension @
68-F
Dy nee/cm
23.7
24.6
24.8
25.2
m
22.7
25.5
-
39.6
•
.
29.8
KETONES
ACETONE
METHYL ETHYL KETONE
DIETHYL KETONE
METHYL n-PROPYL KETONE
CYCLOHEXANONE
METHYL ISOBUTYL KETONE
METHYL n-BUTYL KETONE
METHYL CYO.OHEXANONE
(Mixed Isomers)
ACETONYL ACETONE
DIISOPROPYL KETONE
METHYL n-AMYL KETONE
D1ACETONE
Formula
CH,COCH,
CHjCOC^H,
CjHjCOCjH,
CH-jCOCjHT
(CHj)5CO
(CHJjCHCHjCOCHj
CHjCOC.H,
(CHJCsHgCO
CHjCOCjH^COCH,
(CH-jJ^HCOCHfCHjIj
CH3(CHj)4COCH,
(CH-^CfOH) CH2COCH3
Sol % by Wt ฉ
68*F
In Water
•
26.8
3.4'ฐ* f
4.3
2.3
2.0
M77"'
02.
•
0.6
0.4
ซ
O' Water
•
11.8
4.6
33
8.0
1.8
3.7"*F
3.0
•
-
1.5
-
Flaiih
Pt
fTCC)
•F
0
28
55
45
145
64
73
118
174
75
120
48
Flammable
Limits
% by Volume
in Air
Lower
2.6
1.8
.
1.6
1.1
1.4
1.2
-
.
.
.
-
Upper
12.8
11.5
.
8.2
.
7.5
8.0
•
.
-
.
-
Toxicrty
MAC
in ppm
1000
250
250
200
100
100
100
100
.
.
100
50
Spec. Heat
Lkj. @
68ปF
Btu/(lb)(*F)
0.51
0.53
0.56
.
0.49
0.55
0.55
0.44"-'
.
.
.
O-SO**'
Latent
Heat
<ง>
B.P.
Btu/16
224
191
163
180
ป
148
148
••
.
•
149
200
Source: DuPont Company. Handbook of Standards for Solvents

-------
 50
                                  Exhibit 15b
                       PROPERTIES OF ALCOHOLS
PRODUCT
Metnanol
Ethanol. Prop. Anhydrous
Ethanol, Spec. Industrial Anhydrous
Isopropanol. Anhydrous
n-Propanol
2-Butanol
fsobutanol
n-Butanol
Amyl Alcohol (primary)
Methyl Amyl Alcohol
Cyclohexanol
2-Ethylhexanol
Texanol
3MปJ i 1 1 "-A."-L .'I. i '• •-— j.^— i 	 ^^ _
Lb./Gal.
60' F
6.60
6.65
6.65
6.55
6.71
6.73
6.68
6.75
6.79
6.72
7.89
6.94
7.90
=====
Sp. Gr.
20'/20'C
0.792
0.799
0.795
0.786
0.806
0.809
0.803
0.811
0.815
0.808
0.949
0.834
0.950
======
Boiling
Range "F
147-149
165-176
167-178
179-182
205-208
207-215
225-228
241-245
261-282
266-271
320-325
360-367
471-477
=========
Fl. Pt.
•FTCC
54
49
50
S3
74
72
85
97
120
103
142
164
2482
1
Evap. Rate1
3.5
1.8
1.8
1.7
1.0
0.9
0.6
0.5
0.3
0.3
0.05
0.01
0.002
i •
1 n-Butyl Acetates 1
2 C.O.C.
Source: Southwest Chemical Company, Solvent Properties Reference Manual

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                                              51
                 Exhibit 16



PROPERTIES OF OTHER CHLORINATED SOLVENTS
Physical Properties
Ozone Depleting
Potential
Chemical Formula
Molecular Weight
Boiling Point ('C)
Density (g/cm3)
Surface Tension
(dyne/cm)
Kauri Butanol Value
Toxicity
OSHA PEL 8 hr.
TWA (ppm)
Flash Point (*C)
• Obtained from HS1A
Source: UNEP 1989.
CFC-113
0.8
CClgFCCIFg
187.38
47.6
1.56

17.3
31
Low
1000
None
White Paper 1989.

MCF
0.1
CH3CC!3
133.5 ;
72-88
1.34

25.4 i.
124 • ;
Low •
350* ;
None

Trichloro-
ethylene
0
CHCICCIj
131.4
86-88
1.46

29.3
130
Medium
50*
None

Perchlpro-
ethylene
0
CCfeCCfe
165.9
120-122
1.62

31.3
91
Medium
25ซ*
None
X
Methylene
Chloride
-0
CH2Cl2
84.9
39.4-40.4
1.33 •

N/A
132
Medium
500*
None


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52

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                                                                                          53
WASTEWATER  MINIMIZATION AND
TREATMENT
Wastewater generated from aqueous and semi-
aqueous based cleaning processes used in the metal.
cleaning industry might require pretreatment prior
to discharge to the sewer system to meet local,;
state, ^or federal regulations.   The amount of
pollutants  and  the  quantity of wastewater
generated depend on the cleaning process.  The
type of treatment technology used depends solely
on  the quality and  quantity of the wastewater
generated.
Contaminants

The wastewater generated from aqueous and semi-
aqueous based cleaning processes can contain
organic  contaminants  along with  dissolved  or
suspended   metals.    An  additional  problem
encountered with alkaline cleaners is the high pH
of the wastewater.
Organic Matter

Organic matter in  the wastewater results  from
removal of oil and grease from the parts being
cleaned and from the chemical constituents of the
cleaners.

Generally considered a single type of pollutant, oil
and grease are not categorized by any chemical
formula, but rather as a general type of semi-liquid
material that may contain fatty acids, fats, soaps,
and other similar materials. Oily wastewater can
be placed into five categories:

• Free oil:  oil which rises rapidly to the surface
  under quiescent conditions;

• Mechanical dispersions: fine oil droplets ranging
  in size from microns to  a few millimeters in
  diameter which  are  stabilized by  electrical
   charges or other  forces but  not through the
   influence of surface active agents;

   Chemically  stabilized emulsions:  oil droplets
   similar  to  mechanical dispersions  but with
   enhanced stability resulting from surface active
   agents at the oil/water interface;

•  "Dissolved* oil:  truly soluble  chemical species
   plus very finely divided oil droplets (typically
   less than  5 microns  diameter).   This  form
   generally defies removal  by  normal physical
   means;

•  Oil-wet solids: oil  adhering to the surface of
   paniculate material in the wastewater.

Organic matter such as oil and grease contribute to
visual  and  olfactory problems, interfere  with
normal oxygen transfer from air to water, and exert
both a biological oxygen demand (BOD)  and  a
chemical oxygen demand (COD).  The measure of
organic matter in a waste  stream is  generally
characterized by measuring the BOD and COD.
BOD is  a  measure of  the oxygen consuming
characteristic of organic matter.   COD measures
oxygen consuming pollutants in wastewater. COD
measures the  total  oxidizable   carbon in  the
wastewater and relates to the chemically bound
oxygen in the water. BOD relates to the dissolved
oxygen.

Most aqueous and semi-aqueous chemicals used in
cleaner formulations are biodegradable.  The term
"biodegradable* may be misleading, because it may
take too long for these chemicals to break down
into their constituent elements to be considered
"environmentally acceptable."

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  54
  Metals

  Metals can exist either in suspension or solution.
  Metals in suspension are metal chips and fines
  removed from the parts being cleaned. Dissolved
  metals are metals in solution.  Dissolved metals in
  aqueous-based wastewater generally arise  from
  metals that are etched off  as a result  of the
  alkalinity of the solution.
  PH

  A high pH, or alkaline content, can harm aquatic
  life. Aqueous cleaning wastewater generated in the
  metal cleaning industry is generally alkaline  (i.e.,
  has a pH greater than 7) and in most instances, it
  has  a  pH ranging from 9  to  12 and  must be
  neutralized prior to discharge.
 Wastewater Minimization

 Before discussing wastewater treatment options, we
 discuss methods for minimizing the amount of
 wastewater generated from aqueous  and semi-
 aqueous cleaning processes. One of the key factors
 in minimizing  wastewater is to  optimize  the
 cleaning process.

 Optimizing the cleaning process includes:

 • Avoiding unnecessary loading

 •  Removing sludge promptly

 •  Monitoring the cleaning solution

 •  Maintaining equipment

 •  Designing more efficient process features.


Avoid Unnecessary Loading

In addition to consuming  cleaner,  an excessive
amount of loading causes the soils removed from
the pans to interfere with cleaning.  These solids
form scale on the heating tubes and reduce heat
transfer efficiency.   Excessive  loading  requires
regular maintenance and increases  discharge of
wastewater.
  When  using alkaline cleaners, alkalinity may be
  reduced by the acidity of the soils being removed.
  reaction of the alkali with the carbon dioxide in
  the air -used  for  agitation, and  reaction of the
  cleaner components with the hard water  salts.,
  This reduction in  alkalinity consumes the cleaner
  and reduces bath life. Solutions to such problems
  include using  mechanical agitation,  soft water,
  demineralized  water,  or deionized water,  and
  frequent replacement of the used alkaline cleaner.
  Remove Sludge and Soils Promptly

  Removing sludge and soils promptly from cleaning
  tanks will reduce cleaner use by increasing the time
  before the entire tank needs to be cleaned out

  Alkaline  cleaners  are available that allow the
  separation of excess oily soils from the cleaning
  solution.  These formulations use surfactants that
  are  good  detergents  but  poor  emulsifiers.
  Agitation of the bath during cleaning keeps the
  soil  suspended.   After a  prolonged period  of
  inactivity, such as overnight, the oily soils float to
  the surface and can be skimmed off.  Although this
  method is effective with  mineral  oil,  it is less
 effective with fatty oils.

 Similarly there  are also semi-aqueous  cleaning
 systems that have  a  hydrocarbon phase that
 dissolves  the soils  but  does  not dissolve in the
 water phase.  When allowed  to stand  without
 agitation, this hydrocarbon phase easily separates
 out.
 Monitor Cleaning Solution Routinely

 If solution strengths are analytically checked on a
 routine basis, solution strength can be maintained
 more effectively by making small and  frequent
 additions rather than a few large ones. Analytical
 checks can be performed by the operator using
 simple  titration techniques  (for  example,  the
 addition of a given amount of reagent to  a known
 volume of cleaner and indicator can result in a
 color change).  Full scale titration tests may be
 performed by a laboratory on a less frequent basis.
An accurate log of all tests and cleaner additions
should be  kept.

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Maintain Equipment
Oil and Groase
All equipment should be regularly maintained.
Metal  tanks should  be .properly coated  with.
protective finishes.   Deionized water should be
used in tanks  with plastic lining.  Spray nozzles
should be inspected  regularly to avoid  clogging.
Another important item that should be maintained.
is float valves that supply make-up water. Leaks in
these valves can cause dilution of cleaner.  It is.
also important  to   determine  whether  plastic
material used in equipment is compatible with the
hydrocarbon material used in the semi-aqueous
process.
Consider Other Process Design       \
Features

Other   process  design  features  that   reduce
wastewater discharge include:

•  Use of demineralized water for cleaning needs
   that cannot tolerate minor residue on the parts.
   Rinsing   should   be  carried   out   using:
   demineralized water.  This water reduces the
   amount of sludge generated during wastewater
   treatment and may allow the direct use of rinse
   water as make-up water for the wash tank;
                                            I
•  Counterflow rinse  systems should  always be
   used to reduce overall water consumption and
   subsequent treatment requirements;

•  Fog  nozzles   use  much  less  water  than
   conventional spray systems.
Wastewater Treatment
Technologies

Wastewater  generated from  these processes can
have a wide range of pollutants; therefore, the
treatment technologies applied will depend on the
type of pollutant  present and the quantity  of
wastewater  being  generated.   The  wastewater
treatment equipment and  processes discussed
below  are  categorized  based  on the type  of
pollutant being treated.
Gravity Separator. This treatment technology takes
advantage of  the  difference  in specific  gravity
between  water and  oil  and  grease.   Gravity
separators are the most common devices employed
in waste treatment to separate grease and non-
emulsified oils.  The technique does not always
remove  very finely divided (colloidal)  oily  or
scummy material.  The process generates an oily
dispersion that may have to be treated prior to
disposal.  Relative energy requirements are low.
The treatment process involves retaining the oily
waste in a  holding  tank and allowing  gravity
separation of  the  oily  material which  is  then
skimmed from the wastewater surface.

In instances where the quantity of wastewater to be
treated is small, a simple skimmer  attached to a
tank can be used to remove the free floating oils -
a process commonly used in metal cleaning. The
oil skimmers  either  are operated  continuously
during cleaning or are operated once a day before
the cleaning  process is started. It should be noted
that during  the removal of oil, other suspended
solids, like metal fines and chips, are also removed.

Ultrafiltration. Ultrafiltration is a low pressure (10-
150 psi)  membrane process for separating high
molecular weight emulsified oils and paniculate
matter less than 0.2 microns in diameter. A semi-
permeable membrane, incorporated  in membrane
modules, performs the separation. The wastewater
feed  is  pumped  under  pressure  tangentialiy
through the  membrane modules.  Water and low-
molecular weight solutes such as salts  and some
surfactants,  pass orthogonal to the direction  of
flow through the membrane pores  as  permeate.
The solution may  be  reused  or further treated
prior  to disposal.   Emulsified oil and suspended
solids cannot pass  through the membrane pores
and are retained as a concentrate. Capital cost for
ultrafiltration  equipment  and  operating  costs
associated with  pumping the solution at elevated
pressure are  higher than other treatment methods.
Material and disposal cost savings can provide an
acceptable return on investment in  cases where
recycling of the permeate solution is possible.

Wastewater flows across the membrane surface  at
high velocity. This cross-flow characteristic differs
from the perpendicular flow of ordinary filtration,

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   56
   where  "cake"  builds  up  on  the  filter  surface.
   requiring frequent filter replacement and cleaning.
   Tangential-flow  prevents  filter  cake  buildup,
   resulting in high  filtration  rates  that  can be
   maintained continuously, eliminating the cost for
   frequent membrane cleaning.

   Data from aerospace industry investigators indicate
   thai a ceramic ultrafiltration system can be used to
   recover the entire cleaner (builder and surfactant
   package)  used  in aqueous cleaners and that the
   efficiency of  oil  removal  is  best  when using
   ultrafiltration. However, the ultrafiltration process
   must be closely tailored for the particular aqueous
  cleaner in  order  to  prevent  excessive  loss of
  specific components.

  Coalescing.  The basic  principle of coalescence
  involves the preferential wetting of a coalescine
  medium by  oil  droplets that accumulate on  the
  medium  and then  rise to the surface  of  the
  solution as they combine to form larger particles.
  The important properties of the coalescine media
  are its wettability for the oil and its Iarge~surface
  area.  Polypropylene and monofilament line  are
  sometimes used as  coalescing media.  Floating
  absorption blankets  or pillows  are available from
  a number of suppliers.   The  active material is
  generally a blown polypropylene, which is  highly
  oleophilic, but will not remove active ingredients
  from the cleaner.

  Because of its simplicity, coalescing provides high
  reliability and low capital and operating cost.  It
 cannot be  used, however,  to remove emulsified
-oils,  if they are present,  they must be pretreated
 before being sent to the coalescing unit.

 Chemical Treatment.  Chemical treatment is often
 used  to breakdown  stable oil-water  emulsions.
 Chemical treatment consists of three steps: (1)
 coagulation  -  breaking of  the emulsion, (2)
 flocculation -  agglomeration  of the  tiny oil
 droplets  to  form   larger  droplets,  and  (3)
sedimentation - the removal of oil from water.

Chemicals  ( e.g., polymers, alum,  ferric chloride,
and organic emulsion breakers) break emulsions by
neutralizing repulsive charges between panicles,
precipitating or salting out emulsifying agents, or
altering the interiaciai film between the oil and
witer. After the addition of the coagulant, another
chemical, called  the* flocculent. is  added to
   agglomerate the tiny oil  droplets into larger oil
   drops so that they can be easily separated. Typical
   floccuients are high molecular weight polymers.

   The disadvantage of this process is that  chemical
   treatments used to break the emulsions  generate
   sludge  that  has  to  be  disposed  of.   This
   requirement increases cost, particularly if the level
   of emulsified oil needs special chemical treatment.
  Organ/cs

  Organic present in the wastewater from aqueous
  and semi-aqueous  based  processes are generated
  from contaminants like the hydrocarbon chemicals
  and surfactants used in the chemical cleaners and
  finishing and pigment compounds  used  in  the
  processing of the metal parts in the metal industry.
  Although oil and grease are organic in nature, they
  are not  considered organic pollutants  under this
  definition.   It  is  known that  many oreanic
  compounds arc  eliminated during the treatment •
  steps for the removal of waste  oil and  grease.
  High molecular weight organic are much more
  soluble in oil than in the water and are skimmed
  off with the removed oil.

 Carbon adsorption.   This system involves passing
 the wastewater. through a chamber  containing
 activated carbon to remove the dissolved organic
 from the  wastewater. Carbon adsorption is one of
 the most  efficient organic  removal  processes
 available.    In  addition,  it is reversible,  thus
 allowing activated carbon to be regenerated by the
 application of heat and steam and then  reused.

 Some  general rules relating to  carbon adsorption
 capacity are:

 • Higher surface area gives a greater adsorption
   capacity:

 •  Larger  pore size gives  a greater  adsorption
   capacity:

•  Adsorptivity increases as the solubility of the
   solute decreases.  For hydrocarbons, adsorption
   increases with molecular weight;

•  Adsorption capacity decreases with increasing
   temperature:

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                                                                                                57
•  For solutes with  ionizable groups,  maximum
   adsorption is achieved at a pH corresponding to
   the minimum ionization.

The rate of adsorption  is  also  an  important
consideration.   For example,  while capacity is
increased with the adsorption of higher molecular
weight hydrocarbons, the rate of adsorption is
decreased.  Similarly, while temperature increases
decrease capacity, they may increase the rate of
removal of solute from solution,

Carbon  adsorption  requires  pretreatment  to
remove excess suspended solids, oil, and grease.
Suspended solids in the stream entering the carbon
adsorption bed should be less  than SO pans per
million (ppm) to minimize backwash requirement!..
Oil and grease should be less than 10 ppm.  High
levels of oil and grease can block the pores of the
activated  carbon, making  it  ineffective in  the
adsorption of organic matter.                  \

Activated carbon columns are typically placed in
series or parallel in  wastewater treatment plant;.
A minimum  of two  columns is generally used in
continuous operation:  when the activated carbon
in one column is used up and is being regenerated,
the other column removes the contaminants. An
economical treatment process, the major cost of
activated carbon is associated with regeneration.
pH

Aqueous cleaning wastewater is alkaline and can
have a pH ranging from 7 to 12. depending upon
the cleaning process, and in particular, on the type
and strength of the chemical cleaner used. Adding
sulfuric or hydrochloric acid adjusts the pH of
wastewater. The major investment cost associated
with this treatment is the cost of the mixing tank.
The operating costs, which are primarily the cost
of material, are low.                          ,
hydroxide. The treatment chemicals may be added
to a mix  tank or directly  to  the  sedimentation
device such as a clarifier. The major advantage of
a clarifier is the short retention time required for
settling  of the  metal precipitates.  However, the
cost of  installing and maintaining  a  clarifier are
high. The sludge generated has to  be disposed
according to Federal/staie/or local regulations.

The  performance  of  hydroxide  precipitation
depends on several variables. The most important
factors affecting precipitation effectiveness are:

•  Addition of sufficient excess hydroxide to drive
   the precipitation reaction to completion;

•  Maintenance of an alkaline pH throughout the
   precipitation reaction and subsequent settling;

•  Effective removal of precipitation solids.

In some instances flocculating agents are added to
enhance the sedimentation process.   Hydroxide
precipitation, however, produces sludge that needs
to  be  disposed  of —  a  fact  which  increases
treatment cost.
               This system  uses  the reversible
interchange of ions between a solid and a liquid so
that there is no permanent change in the structure
of  the  solid, the ion-exchange  material   Ion
exchange  is  used in  a number  of  wastewater
treatment  applications, particularly  in  water
softening  and deionization,  to -remove dissolved
metals from solution. The utility of ion exchange
rests with  the ability to reuse the ion-exchange
materials.  Eventually the resin beds will lose their
efficiency and have  to  be either regenerated or'
replaced,  thereby producing  either concentrated
wastewater or a volume of contaminated resin to
be disposed of properly. Relative energy costs for
this system  are low.   For example,  in  the
wastewater treatment reaction to remove lead (Pb):
 Dissolved Metals

 Precipitation. The most commonly used technique
 to  treat dissolved  metals consists of hydroxide
 precipitation followed by sedimentation.  Reagents
 commonly used to effect the precipitation include
 alkaline compounds  such  as  lime  and sodium
                                                        2 Na+ R + Pb
                ,2+
R2 4- 2 Na^
The exchanger R in the sodium-ion form is able to
exchange for lead and, thus, to remove lead from
the wastewater and to replace it with an equivalent
quantity of sodium. Subsequently, the lead-loaded
resin may be treated  with a sodium chloride

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  58	

  solution, regenerating the sodium form so that it       from semi-aqueous processes is a fuel source for
  is ready for  another cycle  of operation.   The       incinerators.
  regeneration  reaction  is  reversible:  the  ion
  exchanger is not permanently changed.



  Conceptual  Design  of a

  Wastewater Treatment

  System

  In  most  aqueous  and  semi-aqueous  cleaning
  systems the wash and rinse water is recycled  and
  reused for a certain  period of time before being
  discarded.  Because of stringent environmental
  regulations, high water costs, and high energy
 costs, recycling of wastewater is recommended.
 Exhibit  17 represents a conceptual design of a
 semi-continuous wastewater treatment system that
 treats  wastewater generated Tram  the  metal
 cleaning industry.

 The system consists of six unit operations.  Unit 1
 is a holding tank where the wastewater generated
 is periodically discharged. Unit 2 is an enhanced
 gravity separator that removes free floating oil and
 suspended solids.  Unit 3 is a ultrafiltration device
 that removes the emulsified-dissolved oils.  Unit 4
 is  an  ion-exchange  column  used to  remove
 dissolved metals. Unit 5 is an activated carbon bed
 used  to remove organic matter. Unit  6 is a pH
 adjusting tank. The  final wastewater discharged
 from this system can  be either reused as  process
 water for an  aqueous or semi-aqueous cleaning
 process  or discharged   to the  Public  Owned
 Treatment Works (POTWs).
 Contract Hauling of
 Wastewater

 For  small users  of  aqueous and semi-aqueous
 cleaning processes it might be more economical to
 contract waste treatment rather than treating it in-
 house.  In some cases, the volume of wastewater
 can be reduced to make it more economical for
shipment (hauling) by evaporating- excess water.
Most companies  that contract haul  the  waste
generally treat it in large treatment facilities such
as large wastewater  treatment plants or large
incinerators where it is burned as fuel.  Waste

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59

Wastewater
Holding
Tank
i '
Enhanced
Gravity •ฃ
Separator ^
Exhibit 17
SEMI-CONTINUOUS WASTEWATER
TREATMENT PROCESS
-> Ultra- _p
•^ Rltration ฃ
\ \
Removal of Removal of
Free OH & Dissolved-
Suspended Solids Emulsified Oil
Source: EPA1989a
Carbon _p^
^ Adsorption r\^ &
"I
Organics
pH

Ion Removal of
tchange Dissolved Metals
'$
Public/
Adiusting ^^. JgjjJ*11
Tank 2^^ Treatment
1 Facility
Reuse as
Process Water
I1S131-5

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60

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SUMMARY AND  REVIEW
The discussions presented in this manual  have described a  step-by-step approach  to
eliminating CFC-113  and methyl chloroform  in solvent cleaning  processes.  The steps
include:
   •   Determine where and why CFC-113 and methyl chloroform is used in cleaning
      operations:

   •   Characterize existing cleaning processes:

   •   Establish criteria for selecting alternative cleaning processes;

   •   Review alternatives that could be used to replace solvent cleaning and determine
      which alternative best suits the cleaning needs:

   •   Consider options for wastewater minimization and treatment.
The next section presents some case studies that provide examples of successful programs
on alternatives being implemented in industry. The case studies are followed by references
and list of vendors that mav be an additional source  of information.

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62

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                                                                      63
CASE STUDIES OF  INDUSTRIAL PRACTICES
The following section presents case studies of alternative technologies.

Mention of any company or product in this document is for informational purposes only and
does not constitute a recommendation, either express or implied, of any such company or
product by EPA, ICOLP, ICOLP committee members, and the companies that employ the
ICOLP committee members.
  The case studies presented include:           "              .     .

  •  Case Study #/:  Evaluation of Aqueous Cleaning tor Aluminum and Ferrous
     Alloys

  •  Case Study #2:  Selection of Aqueous Process for Cleaning Components for
     Solenoid Valves

  •  Case Study #3: A Five Phase Program for Developing Alternative Cleaning

  •  Case Study #4: Program to Eliminate Wipe Solvents Containing CFC-113

  •  Case Study #5:  Biodegradable  Replacements for Halogenated Solvents and
     Cleaners

  •  Case Study #6: Replacement of  Solvent Degreasing for Engineering Prototype
     Pans, Precision Machine Pans, and Various Cleanroom Items

  •  Case Study #7: Program to Eliminate Methyl Chloroform Use in Steel Chan-
     Manufacturing Operations

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64

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                                                                                          65
 CASE STUDY #1:
 EVALUATION  OF
 AQUEOUS CLEANING
 FOR  ALUMINUM  AND
 FERROUS ALLOYS
 Case  Study  #1  is an  overview of  the  work
 conducted by Boeing since mid-1987 to evaluate
 aqueous cleaners and the aqueous cleaning process.
 The current status of the program encompasses the
 use of aqueous cleaning for aluminum and ferrous
 alloys.  Work on titanium and magnesium allow.
 although virtually complete, is still in progress.
 Selection  of Cleaners for
 Evaluation

 An initial list of 10 cleaners was developed from
 vendor listings available through the literature, by
 selecting companies recognized as Boeing suppliers
 in other product areas.  Selection criteria of the
 cleaners for evaluation  include indicated cleaning
 effectiveness,   low   toxicity  materials,   and
 regeneration capability. As the project progressed.
 more contacts  were  made  both within   the
 aerospace industry  and  with other  chemical
 suppliers.   These contacts led to the eventual
 evaluation of 48 aqueous cleaner formulations, all
 meeting the initial selection criteria.
Cleaning Effectiveness
Testing

The evaluation of aqueous cleaners began with the
specification of the soil to be removed and the
determination of cleaning performance.   Most
industrial specifications require only that a cleaner
Heave no visible residue." Two specifications were
found that detail test soils to be removed (SAE
AMS  1536  and  1537)  and  the amount of soil
removal required, as measured by weight Cleaners
for the evaluation  were expected  to  remove ail
visible soils, so the measurement of soils removed
  by weight was not applicable.  In addition, vapor
  degreasers ai Boeing arc often  general cleaning
  operations that must remove a variety of soils from
  a  number  of  substrate  materials.   For these
  reasons,   no   particular  standard   cleaning
  specification appeared applicable.
 Immersion Cleaning

 Immersion  cleaning  effectiveness  tests  were
 conducted on aluminum, steel, and titanium test
 panels using as test soils "permanent" marking ink,
 general purpose lubricating grease, silicqne grease,
 general purpose lubricating oils, rust preventive
 compound, tar. lipstick (not a shop soil but a
 highly visible  hydrocarbon  mixture), solder flux,
 and machining wax.  Cleaners were made up in
 bench-scale  quantities (2 liters), and generally
 operated at two concentrations and over a temper-
 ature range based on suppliers' recommendations.
 Agitation was limited to  that necessary for
 temperature control. Immersion time was set at 20
 minutes with qualitative evaluation of the cleaning
 effects performed every five minutes.  Cleaning was
 followed by immersion rinsing in warm water.

 Degreasers were  described  as  vigorous  if a
 particular soil was completely removed within 10
 minutes.  Other terms were used to describe
 removal or visible effect on soils at particular time
 intervals. After the completion of testing, cleaners
 that indicated an ability to quickly remove a broad
 spectrum of soils were judged as "most effective."
 This judgment was made recognizing that, for a
 specific cleaning operation, degreasers that ranked
 lower in overall effectiveness may be appropriate
 choices for the removal of particular soils.
Spray Cleaning

A single-nozzilc spray tank was constructed for the
evaluation of spray cleaners.   Cleaners  were
evaluated using  the same soils and substrates
described for immersion  cleaning.   However,
cleaning time was limited to 15 minutes and some
evaluations were conducted at five seconds interval
for light hydrocarbon oils. Cleaning was followed
by spray  rinsing with  room temperature water.
Effectiveness was again based on broad spectrum
soils removal.

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  66
  Ultrasonic Cleaning

  Evaluation was conducted using a laboratory scale
  ultrasonic cleaning bath with a capacity of about
  two liters. Cleaners were evaluated using the same
  soils  and  substrates described for  immersion
  cleaning, but with the addition of some tubing
  materials for test substrates.  Cleaning time was
  limited to 15 minutes.  Cleaning was followed by
  spray  rinsing  with  room  temperature water.
  Effectiveness was again based oh broad spectrum
  soils removal.
 Results of Cleaning

 Effectiveness Tests

 Based on  the qualitative evaluation of cleaning
 effectiveness, a number of conclusions were drawn:

 • Several  cleaners  were  evaluated  that were
   determined to be highly effective cleaners. All
   cleaners tested showed at least some ability to
   remove   general   purpose  lubricating oils.
   However,  the vigorous cleaners were  readily
   apparent by their effects on the other test soils,
   ink, and silicone grease  in particular.  The
   vigorous cleaners were then permitted to enter
   the more extensive test phase of the program
   described in the following sections.

 •  The effect of substrate on cleaning effectiveness
   was not strong, some indication that soils were
   harder to  remove from  steel  than   from
   aluminum.

•  As expected  the  effect of temperature was
   significant   in  testing  at  room temperature,
   degreasers  that showed some effectiveness were
   generally  much  more  active  when  heated.
   Temperature  for  the  cleaning process was
   limited to  14QฐF to prevent flash drying onto
   substrate surfaces.

•  As expected the effect  of agitation was also
   significant.    Spray  cleaning  and ultrasonic
   cleaning generally  took half the time of low
   agitation immersion cleaning.
  Metallurgical Testing

  Metallurgical tests were conducted to assure that
  the aqueous cleaners did not cause any adverse
  effects on substrate materials.
  Etch Testing

  Etch testing was  conducted according to Boeing
  specifications. Test metals were immersed in the
  cleaners at operating concentration and tempera-
  lure for 24 hours. The amount of weight lost by
  the test metals determined the acceptability of the
  cleaners.  All vigorous cleaner candidates passed
  this  test.  Cleaners  that would not pass this test
  were apparent in immersion cleaning effectiveness
  testing, due to the staining and gassing observed.
 Intergranular Attack and End Grain
 Pitting

 Intergranular testing was carried out according to
 Boeing specifications.  Metal test specimens were
 exposed to cleaners at operating concentration and
 temperature for 30 minutes.  Specimens were  then
 cross-sectioned to determine that  intergranular
 attack in  excess of 0.0002 inches and end grain
 pitting in  excess of 0.001 inches had not occurred.
 All vigorous cleaner candidates passed this test
Sandwich Corrosion

Sandwich-corrosion testing was carried out using
Boeing  specifications.    Results  of sandwich
corrosion icsts indicate the corrosion  that  can
occur if, during the rinse cycle, the cleaners are not
adequately removed from the surface. In  general,
alkaline-based cleaners were marginal to failing on
this test  The terpene-based emulsion  cleaners
tested, however, did not indicate any corrosion
potential.

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                                                                                             67
Hydrogen Embrittlement of High
Strength Steel

Testing was conducted in accordance with ASTM
F519, using both cadmium plated and unpiated
Type  1A steel  specimens.   In  this test, the
specimens are subjected to 45 percent of their
ultimate tensile strength while immersed in the test
cleaner.  The specimens must not  break  for a
minimum of  150 hours.    The  terpene-based
emulsion cleaners passed all tests.  The alkaline-
based cleaners passed the test with bare steel but
failed with cadmium-plated steel due to caustic
driven cadmium reembrittlement of the steel test
specimen.
Effects on Subsequent

Processes

Substituting the aqueous  cleaning  process for
vapor degreasing must not adversely affect the
chemical  processes  that  follow.   What  was
unknown  was whether any  residue from the
aqueous   cleaners  would  affect  subsequent
processes.  The most straightforward method to
look for adverse effects was judged to be the
quality of subsequent finishes.  The following tests
were conducted by using the candidate  aqueous
cleaners prior to finishing aluminum, followed by
standard quality control tests  in accordance with
specification requirements:

• Chromau conversion  coating — 168-hour salt
  spray,

• Chromic acid anodizing - 336-hour salt spray;

• Chromau conversion  coating followed  by  epoxy
  primer ~ wet  and dry adhesion tests, impact
  resistance, 3,000-hour scribe line corrosion test,
  and 30-day  acidified salt  spray coupled with
  CRES;

• Chromic acid anodizing followed by epoxy primer ••
  wet and dry adhesion tests, impact resistance,
  3,000-hour scribe line corrosion test, and 30-day
  acidified salt spray coupled with CRES;

• Chromau conversion  coating followed  by  epoxy
  primer and epoxy enamel •• wet and dry adhesion
   tests, impact resistance, 3,000-hour scribe line
   corrosion test, and 30-day acidified salt spray
   coupled with CRES;

•  Chromic acid anodizing followed by epoxy primer
   and epoxy enamel — wet and dry adhesion tests,
   impact  resistance,  3,000-hour   scribe  line
   corrosion  test. 30-day  acidified  salt  spray
   coupled with CRES;

•  Phosphoric acid anodizing followed by adhesive
   bonding — crack extension test;

•  Phosphoric acid anodizing followed by epoxy primer
   -' wet and dry adhesion tests and 3,000-hour
   scribe line corrosion test

The following tests were conducted by using the
candidate aqueous cleaners prior to finishing steel.
followed by standard  quality  control tests for
specification requirements:

•  Stainless steel passivation - salt spray verification
   test;

•  Cadmium plating — adhesion;

•  Chromium plating — adhesion;

•  Cadmium-titanium alloy plating — adhesion.

None of  the tests for subsequent effects have
indicated a failure due to the use of the aqueous
cleaners.
lexicological and Industrial
Hygiene Analysis

Candidate cleaners were initially selected to be low
toxicity materials, based on supplier information.
However. Boeing requires that all new materials be
evaluated prior to their use. These evaluations are
still in progress for several of the effective cleaner
candidates.   Evaluations of d-limonene and the
glycol ethers  have been completed and  will be
made available to other organizations on request.

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 68


 Cleaner Regeneration

 All the cleaners selected for evaluation have some
 degree of soil rejection capability. Soil rejection
 capability  is  accomplished  by  the surfactant
 package included in the cleaner.  The surfactant
 package reduces  surface  tension  for effective
 contact by the cleaner's active ingredients, but then
 does not allow the removed hydrocarbon soils to
 be emulsified in the cleaner.  As  a consequence.
 oils and greases float on the top of a quiescent
 emulsion  cleaner  tank.    The  soil  rejection
 capability provides  an  opportunity to regenerate
 the cleaner, greatly extending operating life and
 reducing  the  volume  of  hazardous   waste
generation.  Rejected  hydrocarbon soils can be
removed .from an  operating aqueous cleaner  in
several  ways: skimming off the oil. absorption
using floating absorption blankets or pillows, usine
a coalescer, and through uitrafiltration. .

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                                                                                       69
 CASE STUDY #2:
 SELECTION  OF
 AQUEOUS PROCESS
 FOR CLEANING
 COMPONENTS  FOR
 SOLENOID VALVES
 Case Study #2 describes a program implemented
 at Honeywell to select an aqueous cleaning process
 for cleaning components of solenoid valves.

 Honeywell. Skinner Valve Division, produces
 solenoid valves for use in  fluid  control.  The
 majority of components are 300 and 400 series
 stainless steels with some brass and aluminum.
 Parts typically range in size from one-half inch in
 diameter  by one  inch long to two inches  in
 diameter   by  four inches  long.   Operations
 performed  include  turning,  milling,  drilling,
 threading, broaching, and welding. Valves are used
 in a variety of applications such as gasoline pumps,
 medical oxygen equipment, and photocopying
 equipment.
Current Process

The major cleaning objective is to remove cutting
oils and chips from blind holes.  Final cleaning is
performed prior to  welding and assembly.   Ail
work  moves  through  two  vapor degreasers
equipped   with  hoods,  programmable  hoists.
ultrasonics, and attached recovery stills.  Parts are
degreased  between  operations and  also before
assembly.    .Parts  are racked  in  metal trays
approximately 10 inches x 16 inches, loaded three
at a time into a rotating basket. Typical trays hold
40 to 200 parts depending  on size.  Total cycle
time is five minutes.  Annual volume is 1.2 million
valves. Each  valve contains five or six major
components and each component is degreased at
least two to three times. This results in over 16.5
million parts  passing through the degreasing
operations.  Consumption of CFC-113  for 1989
was 54,000.ibs.
 Alternative Selection
 Process

 In response to the concerns with CFC-113, the
 Environmental  Health  and  Safety  group  at
 Honeywell  issued a  policy for  all  divisions  to
 reduce usage and ultimately eliminate CFC-113. A
 central group was formed to study the problem and
 relay information and findings to other divisions.

 It was decided to avoid any replacement of CFC-
 113  with "in kind" HCFCs because of pending
 legislation thai would ultimately regulate these
 solvents.  In addition. HCFCs were not expected to
 be in production until 1992 and would require
 newer and more .expensive equipment.  Costs of
 HCFCs were expected to be at least equal to or
 greater ihan CFC-113.

 Because there were  no  tight spaces to trap a
 cleaning  fluid (as there might  be  for  surface
 mounted electronic components)  the low surface
 tension and high evaporative rate of CFC-113 were
 not  a  factor.  The cleaning of parts  between
 machining operations did not require a high degree
 of cleanliness; removal of the bulk of the oil and
 all of the loose chips would be sufficient.

 Health and safety factors were considered. No
 substance that was more toxic or presented a
 greater health risk than the current process would
 be accepted.

 Lastly, cost was a large factor.  It was established
 through vendor tests that relatively  inexpensive
 equipment could fill the cleaning needs and still
 achieve a less than two-year payback.

At Skinner  Valve, two engineers  were given the
 task of meeting the corporate goals.  Using both
corporate  resources  and  cleaning  equipment
vendors, these engineers  outlined the following
steps to replace CFC-113 as a metal cleaning fluid.

• Develop an objective and guidelines;

• Identify information sources;

• Identify baseline what, why, where, how, cost;

• Establish current material flow,

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  70
  •  Identify equipment options:

  •  Run test on vendors equipment:

  •  Compare test results between different type of
     cleaning machines;

  •  Identify cleaning solution options:

  •  Identify waste handling options:

  •  Perform financial analyses;

  •  Order Phase I equipment:

  •   Install and debug equipment:

  •  Review results of Phase I equipment:

  •  Order Phase II equipment:

  •  Install Phase II equipment: and

  •  Obsolete vapor degreasers.


 Cleaning Requirements

 The factory  has  been restructured into a cell
 concept with Just in Time (JIT) manufacturing.
 This structure required decentralized degreasing
 operations, preferably units small and inexpensive
 enough  to place one at every work station.

 Several different levels of cleaning  are required.
 These were broken down into three  levels:

 Level 1  includes  those  parts   that  must  be
 completely  cleaned with  no  oil or  chips  and
 completely dry with no residue. "Oxygen service"
 parts are the  most demanding since they will be
 used in oxygen regulators and medical equipment.
 No  hydrocarbons can be allowed.  Inspection is
 done under ultraviolet light and the cleaned pans
 are  handled  with  cotton  gloves and placed in
 plastic bags until final assembly.

 Level 2 includes normal cleaning prior to assembly
 or welding.  Parts must be free of dirt and oil, with
 no chips, and dry.

 Level  3  includes  pans   primarily  between
operations and is intended to remove the bulk of
   the oil and chips so that a pan can be handled and
   located for the next operation.  Depending on the
   next operation, it is not necessary for the pan to
   be dry, for example, tumbling and passivation.

   Ranking  the work  by levels provided a  better
   breakdown of the numbers involved and how many
   locations and types of machines would be required.
  Tests were performed on representative samples of
  the different types of parts and the different levels
  of cleaning required.

  After the decision was made to use an aqueous
  system, the question of waste material was still a
  major concern.  Options included shipping waste
  solution and  rinse water off site; this was rejected
  as being  too expensive. On-site  treatment was a
  less costly answer.

  Honeywell  considered on-site  treatment  and
  disposal   into the sewer  which  would require
  constant  monitoring  and would become  more
  difficult as more facilities attempted to discharge
  aqueous wastes to the sewer.  Other treatments
  considered included ultrafiltration and evaporation.
  Evaporation  was  chosen  for  this  application
  because rinse water volumes were low and tiie
  absence of a liquid waste stream limited the risk of
 spills  and avoided the possibility of exceeding
 treatment  limits.
 General Description

 The approach taken was to select the equipment
 first and then find the best cleaning solution for"
 each  application.   The  selection of  cleaning
 solutions is still in progress.   The preference of
 this team  is to use one  of  the npnemulsifying
 cleaners to facilitate oil separation.' '

 Three separate systems were selected: mechanical
 agitation, spray washers, and ultrasonics.
Mechanical Agitation

In general  these units consist of a tank with a
movable rack.  The rack is set to submerge the
work piece in a heated solution and move the work
piece  up and  down a set frequency.   Working
temperatures range from  room  temperature to

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                                                                                               71
180ฐF: agitation can  be varied with  respect to
length and  speed of the stroke.   One system
purchased also  contains  a  heated rinse.   Oil
skimmers are either belt or disk type units with a
separate secondary oil-water separator.  Trays are:
filled at the rate of one every IS  minutes: the
operator places the tray onto the work rack andl
starts a five-minute cycle. Solution temperature is;
set at 135ฐF.  The parts are oriented  to  prevent
cupping and dragout.  At the  end of the  wash
cycle, trays are either put through a rinse  cycle or
are allowed  to dry and cool.                    ,
Spray Washers

Units consist of a small conveyor that passes pare;
under a series of high  pressure spray nozzles,,
After washing, parts are passed under an air knife
to blow off excess  solution.   Parts  are then
dropped into  baskets  and  moved  to  the next
operation.  The bulk of these parts continue on to
other  Vet' operations  such as tumbling  and
passivation. Working  temperature  is 135ฐF.  A,
disk  type oil separator is  utilized.
URrasonic

Ultrasonic cleaners are reserved for the highest
level of cleanliness. For critical pans, a prewash in
an agitating washer is used.  An immersion tank
with bottom mounted transducers providing 1,400
watts input is used. A four- to five-minute cycle at
135ฐF followed by a three-bath counter flow rinse
is utilized.  Parts are then dried in a heated tunnel
or a top loading oven.

Key items necessary to implement technology

•  Upper management support.                ;

•  Shop support It was  necessary to work with
   operators  and  supervisors  to  integrate the
   aqueous cleaning process.

•  Time allocation.  Sufficient  time was allocated!
   to  do   the   necessary   research   and
   experimentation  to find the best available
   technology.
Costs of Technology

Total costs  for  the existing CFC-113  cleaning
system and a projected cost for the replacement
system was established. Material costs were based
on current consumption  and price of CFC-113.
The consumption estimate incorporated reductions
in CFC-113  use. resulting  from  conservation
practices adopted at Skinner Valve. However, the
CFC-113  price calculation did  not  take into
account the  future price  increase and the excise
tax.

Additional costs items included waste removal and
utility costs.  Labor costs were assumed not to
change.   Salvage value of vapor  degreasers was
taken as zero, since it was difficult to determine
what if any market value they might have.

Cycle times  lor aqueous processes are usually
longer and throughput rates are lower. However,
aqueous machines costs less than vapor degreasers.
thus allowing the purchase of multiple units.

The  largest  savings  occur  in  material  costs.
Cleaner cost  for one machine were estimated at
S35 to S50. This is based  on the utilization of the
cleaner  for up to one month.  Actual use shall
depend  on the  volume and type of soils being
removed.  Costs of the aqueous cleaner  is about
the costs of two gallons of CFC-113.

Based on  the project equipment list and current
CFC-113 cost., Skinner Valve expects  to have a
payback period of less than one and half year.  If
existing vapor degreasers can be sold or transferred
to another division, payback will be even  shorter.

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 72
 CASE STUDY #3:
 A FIVE-PHASE PROGRAM
 FOR DEVELOPING
 ALTERNATIVE CLEANING
 Case Study #3 is an overview of the progress made
 by  General Dynamics  Fort  Worth Division
 (GD/FW) to eliminate halogenated solvent vapor
 degreasing and MCF ambient immersion cleaning.
 After  establishing  a  working  team  with
 representatives from all functional departments in
 1987,  criteria  were  established  to  identify
 acceptable alternatives and concrete  goals and
 milestones were set. The project was divided into
 the five phases discussed below.
 Phase I - Soil, Cleaner, and
 Parts Identification/
 Characterization

 In Phase I, the soils and production operations
 that generate parts requiring degreasing  were
 characterized.  Concurrently, the chemist on the
 team  began  identifying  alternative  cleaning
 materials and  processes.   Formulations  that
 contained any hazardous or restricted constituents
 were excluded as well as materials which could
 emit VOCs or toxic air emissions.
Phase II - Cleaner

Evaluation and  Optimization

The  Phase  II evaluation focused on  cleaning
capability using a combination of water break,
ultraviolet light, and acid copper immersion to
determine cleanliness.  Over fifty commercially
available aqueous detergent and emulsion cleaners,
nine terpene hydrocarbon formulations, and several
CFC-113 blends (for comparative purposes) were
screened.  Concentrations and temperatures were
varied for three fixed immersion periods. Cleaners
were also tested for any gross corrosion or adverse
effects on materials. Six products were selected by
mid-1988. Five were selected as general degreasing
 substitutes. The sixth, a terpene hydrocarbon, was
 selected as an option for removing high-molecular-
 weight (asphaltic or paraffinic) soils.
 Phase  HI - Performance

 Confirmation and  Materials

 Compatibility  Evaluation

 In Phase III. the five general degreasing substitutes
 were evaluated in detail for compatibility with
 substrate materials,  surface coatings, adhesfves,
 bonding materials, and downstream metal finishing
 processes.   (These evaluations were similar to
 those shown in case study #1.) Compatibility with
 a  variety  of honeycomb core materials  and
 laminates was also examined.   Three  material;
 were  selected  as   candidates'   for   further
 investigation as  general  degreasing substitutes.
 Additional options for heavy asphaltic soil removal  .
 were developed, and ultrasonics was investigated to
 facilitate cleaning of tubes and heavy  asphaltic
 soils.
 Phase IV - Pilot-Scale
 Performance, Factory
 Evaluation

 The Phase IV factory evaluation and pilot study of
 the final three candidate materials began in mid-
 1989.  In Phase IV,. laboratory performance was
 confirmed on production-sized parts, longer-term
 operational  stability  of  the  solutions  was
 investigated,   foaming  characteristics  were
 examined, operating and maintenance procedures
 were  developed,  an  economic analysis  was
 conducted, and a lexicological and environmental
 impact assessment was  performed.
Phase  V — Development of
Recycling Process

In Phase V, several engineers screened oil removal
technologies and selected a recycle process based
on a ceramic membrane ultrafiltration for further
investigation. The three products were approved

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                                                                                                 73
for  full-scale  implementation  in  early  1990.
Development   of  the   ceramic   membrane
ultrafiltration technology operating parameters was
completed in 1990. One product was identified as
being   completely   recyclable   at   operating
temperatures and concentration. Process emissions
would be limited to an oily emulsion and solution
from the membrane cleaning procedure.

Full-scale implementation is scheduled for 1992-95
and  will  include  an ultrafiltration  system  to
facilitate the recycling of heavily soiled solutions.

Overall, the project has achieved a number of its
objectives:

•  Identified several commercially available water-
   based  cleaners  as effective  substitutes  for
   haiogenated solvent degreasing;

•  Identified alternative cleaners and cleaning
   methods for heavy asphaltic and paraffinic soils
   not cleaned in aqueous immersion cleaners;
                                               i
•  Established  a data  base  to tailor  optimum
   operating conditions for particular degreasing
   requirements:

•  Concluded that efficient cleaning systems can be
   designed  for ail parts configurations, including
   long narrow tubes, using  a variety of off-the-
   shelf equipment; and

•  Demonstrated"  that   using  a   specific
   ultrafiltration technology cleaning solutions can
   be recycled at operating concentrations and
   temperatures.

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  74
  CASE STUDY #4:
  PROGRAM  TO
  ELIMINATE WIPE
  SOLVENTS  CONTAINING
  CFC-113
  Case Study #4 is an overview of how Air Force
  Plant #4. Fort Worth, Texas, developed a way to
  eliminate CFC-113 use by formulating a low vapor
  pressure wipe solvent  and by finding a different
 .technique for the disposal of wipe solvent cloths.

  Currently, Volatile Organic Compound (VOC)
  emissions from wipe solvent are controlled at Air
  Force Plant #4 by using CFC-113  blended with
  hydrocarbon  solvents.  CFC-113  blends reduced
  wipe solvent  VOC emissions by over 60 tons per
 year (tpy).   However,  because of  the CFC-113
  blends, the wipe solvent operations are emitting
 over 230 tpy of CFC-113.

 Air  Force Plant  #4  is located in an ozone
 nonattainment area. Air Force Plant #4 does not
 want to continue to have CFC emissions from the
 wipe solvent operations. Commercial low vapor
 pressure wipe solvents would result in an estimated
 40 tpy increase in VOC emissions.

 Air Force Plant #4 is planning wipe solvent
 operations that would not increase VOC emissions
 over that currently emitted using the  CFC-113
 blends.

 General Dynamics/Fort Worth Division developed
 a plan which involves capturing a patent-pending
 low vapor pressure wipe  solvent before it
 evaporates. Cloths are  used in conjunction with
 the  solvent  in the wipe  solvent (cleaning)
 operations. Most of the solvent  will evaporate
 from the cloth if the cloth is left exposed to the air
 for longer than 15 to 30 minutes. Placing solvent-
 laden cloths in bags immediately after use in the
 cleaning operation prevents solvent evaporation.

 Laboratory evaluation of the bagging concept using
 metallized plastic bags showed that  a maximum of "
94 percent of the solvent could be captured.  When
the bagging concept was evaluated  in the factory,
  there were mixed results depending on the attitude
  of the individual.  A  highly responsible worker
  could achieve about 90 percent capture. A worker
  with no  interest in cooperating can  lower the
  capture to 30  percent.   Typically, the factory
  evaluations resulted in a 60 to 70 percent capture.

  The solvent used is a new. proprietary, lower vapor
  pressure solvent blend that has no CFCs. General
  Dynamics/Fort Worth Division is seeking to patent
  this blend.   When other solvents are used in
  conjunction with the bagging concept, the capture
  rate  is  much  lower  because more  solvent
  evaporates  from the  cloth  during use  in  the
 cleaning operation.

  If the bags are tied off by the  end of the an eight-
 hour shift  and  placed  in  the disposal  cans
 designated for solvent-laden cloths, then the initial
 capture can  be  retained with  less than  a  one
 percent loss.  The disposal cans are emptied daily,
 and bagged  cloths  compacted directly into fibre
 drums.   A  gasketed drum lid prevents solvent-.
 evaporation   from  the  drum  contents.    The
 compaction of the solvent-laden cloths into drums
 is planned to occur within  2 days after its initial
 use in the cleaning operation.

 The compacted  solvent-laden cloths will have
 sufficient energy value to be used as supplemental
 fuel in cement kilns. If the drums of compacted
 cloths are not used for energy recovery,  they  will
 be  incinerated   at  a  commercial  hazardous
 incinerator.

 If the  overall solvent  capture rate exceeds 40
 percent, the Air Force Plant #6 will achieve lower
 VOC emissions than the current  CFC-113  blend
wipe solvent  operations.   Since the new wipe
solvent contains no CFC-113, most of the CFC-113
emissions will be eliminated.

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                                                                                       75
CASE STUDY #:5
BIODEGRADABLE
REPLACEMENTS  FOR
HALOGENATED SOL-
VENTS AND CLEANERS
Case Study  #5 is an overview of the work
conducted since 1987 by the Air Force Engineering
and Services Center,  Tyndall Air Force Base,
Florida, to determine biodegradable substitutes for
halogenated solvents and cleaners used in depot-
level  maintenance  operations.    All  of  the
preliminary testing, including full-scale screening,
necessary to  begin  implementation of non-
halogenated  solvents  and  cleaners  for  metal
finishing throughout the Air Force has been
completed.
Background

Solvents and cleaners are used at the Air Force:
Air Logistics Centers (ALCs) to remove wax,
grease, oil, and carbon from aircraft parts before
repairing or electroplating. Most of these solvent*;
are, or contain ozone-depleting agents. Many are
classified  as  toxic,  and cannot  be treated  in
industrial waste  treatment  plant (IWTPs) than
remove organic chemicals by biological processing,
The process wastes must be shipped to approved
landfills for disposal.
Purpose

The purpose of this program is to:            .

• identify halogenated solvents for removing wax,,
  grease, oil and burnt-on carbon  that can be
  replaced with biodegradable solvents;

• identify the biodegradable solvents that can be
  used:

• develop  procedures for, and implement, their
  use; and                               i
 •  develop procedures for testing future solvents.

 The program has been conducted under contract to
 EG&G Idaho.  Incorporated  by scientists and
 engineers  of the  Idaho National  Engineering
 Laboratory. The program had three phases: Phase
 1 - Solvent Selection and Performance Evaluation;
 Phase  II - Extended  Performance Testing; and
 Phase III - Full Scale Testing.
 Phas& 1 • Solvent Selection and
 Performance Evaluation

 Phase I included five major tasks:

 •  identification of the industrial processes at the
   Air  Force   Depot-Level   maintenance
   organizations  in which  solvents/cleaners  are
   used, the procedures for their use,  and  the
   processes following their use such as inspection.
   electroplating, etc.;

 •  development of quality assurance methods and
   procedures;;

 •  identification of enhancement methods; and

 •  screening   of   solvents  to   evaluate   the
   performance of the biodegradable solvents for
   (a) removing wax, oil. grease, and carbon, (b)
   biodegradahility, and (c) corrosiveness.

 If a solvent  passed the first  three screening
 evaluations, it was then tested for corrosiveness.
 The product v/as required to biologically degrade
 within six hours. Cleaning efficiency, equivalent to
 current processing, was required.
Phase II
Testing
Extended Performance
Extended performance tests on solvents passing the
screening tests, in Phase I, were conducted at the
field test faciiiity at Tinker AFB, Oklahoma. Tests
included  enhancement  methods  (effects  of
temperature,  mixer agitation,  and  ultrasonic
agitation);  cleaning capacity for wax, oil,  and
grease as a function  of solvent loading; rinsing and
drying requirements; and impact on the biological
treatment  plant   at  Tinker  AFB's  IWTP.

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 76
 Information   on   the   toxicity   of  selected
 biodegradable solvents  was obtained  from the
 manufacturers and entered in a database.

 The  solvents  were  tested  to determine  their
 cleaning efficiency.  Preliminary tests showed that
 process enhancement was  needed if aircraft parts
 are to pass the "white glove'  test.  Hence, tests
 were  conducted   using  ultrasonic  and  mixer
 agitation at various temperatures, with and without
 rinsing.  To test solvent performance, the selected
 solvents were loaded with  various amounts of
 masking wax, carbonized oilxylene, or hydraulic
 fluid, and their cleaning efficiency was measured as
 a function of solvent loading.

 Biological acclamation tests were started on Exxon
 Exxate 1000 loaded with oil/xylene.  In the pilot-
 scale solids contact clarifier at Tinker AFB. the
 metal sludge floated to the surface.  Subsequent jar
 tests showed that all of the selected solvents either
 float or disperse the sludge. However, flotation of
 the metal sludge  can be prevented  by adding
 aluminum sulfate,  ferric ion, or magnesium  ion.
 Additionally, magnesium ion addition  caused the
 plant to  be  more susceptible to  upsets  from
 influent   changes,  and  as  a result, is   not
 recommended.  A product, Fremont 776,  was
 added to the  program during Phase   III.  The
 product  passed all the screening  tests that the
 others had,  and did  not  float or  disperse the
 sludge.  Extended corrosion testing indicated that
 general corrosion occurred  in some cases  with
 enhancement   techniques,  especially  with  the
 aqueous  solvents.   In all cases,  no  hydrogen
 embrittlement occurred.

 An ASTM  guideline  is  being developed  for
 determining  biodegradability.  The guideline is
 based on the Phase I screening procedure and an
 eight-day protocol that was completed. Protocol
 testing began by examining  the selection of phenol
 as a.  test control  compound.  Also,  tests were
 conducted to  define  the percentage  of  error
 associated with chemical oxygen demand (COD)
 measurements. The relative error increases as the
 lower  limit  of detection  is  approached  and
decreases  at higher COD analyses.  The error
 appears to be linear. Repeatability tests were also
 conducted, and COD and adenosine triphosphate
 (ATP) averages were plotted. The data from the
TIC/TOC (total inorganic/total organic carbon)
analyses had less variability than the data from
 COD and TOC analyses.  A set of guidelines is
 being developed by  the Air Force and will be
 submitted for review to the ASTM task group on
 biological effects  and  environmental fate.   An
 ASTM set of guidelines will be developed by the
 ASTM  task  group  on  Biological Effects and
 Environmental  Fate.  The set of guidelines will
 include  the screening  test,  the eight-day test
 protocol and the 21 day test as steps in a series of
 logical events that industry can use in determining
 the  biodegradability  of  solvents  for  use in
 individual waste treatment plants.
    The solvents to be used in the full-scale
    Phase  III  tests were selected.   They
    included:

    •   Exxon Exxate 1000:

    •   Bio-Tck # 140 Saf-Solv;

    •   Orange-Sol De-Solv-It:

    •  3-D Supreme; and

    •  Fremont 776.
Phase III • Full Scale Testing

Phase III  testing included cleaning Air  Force
production  parts in an  intermediate scale 100-
gallon agitated tank in a cabinet spray washer and
in a full-scale cleaning tank at Tinker AFB.
Results

Each of the solvents tested in  the full-scale test
program could be applied in cleaning processes at
Tinker AFB.  As expected from earlier testing, the
solvents differed greatly  in their  performance
depending on soil type. Specific recommendations
for solvent use are included below.

3-D Supreme. The cabinet spray washer and full-
scale tests both indicated that 3-D Supreme was an
effective cleaner for Air Force parts.  Applied in
an agitated tank, it would provide an acceptable

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                                                                                                77
 alternative  to  vapor degreasers  now  in service.
 The solvent is effective in  removing oils, grease
 and carbon deposits but should not be considered
 for wax removal.  For both 3-D  Supreme  and
 Fremont 776 rinsing the pans with steam"or high
 pressure spray at  intermediate  points  in  the
 cleaning cycle  would  enhance  the cleaning
 substantially and reduce the overall cleaning-cycle
 time.

 The major drawback in using 3-D Supreme is the
 impact of disposal of used baths  on the solids
 contact  clarifier (SCC) sludge bed  at the I\VTP.
 The 3-D Supreme causes the SCC sludge to float.
 Several solutions to this problem  are the addition
 of small amounts of ferric chloride (FeCI3) to the
 IWTP  process stream:  or  replace the current
 polymer addition with an iron bearing polymer.
 The operator time and chemical and equipment
 expenses involved could be costly.

 It  is  necessary,  when disposing of  used  3-D
 Supreme through an activated  sludge system, to
 maintain a constant feed source to acclimate the
 bacteria to the material. The microorganisms in
 the activated sludge (AS) basin  feed  mostly ori
 phenol and to a lesser extent  on other organic
 constituents in the wastewater. As long as phenol
 is intermittently available, the organisms will feed
 on it and will  not acclimate to  removing other
 organic constituents as efficiently or completely.
 Given the  constant availability of 3-D Supreme,
 the organisms would acclimate, as  evidenced by
 reduction in COD and TOC  concentrations in the
 eight-day tests.   However,  large  fluctuations of
 phenol   concentrations  would   hamper   thai:
 adjustment. If the solvent were stored and fed into
 the  system  continuously,   the  microorganisms;
 should acclimate and degrade the  material.

 Fremont  776.  The Fremont 776 is in  use in a.
 cabinet spray washer, which has  been  used  for
 cleaning fuel control assemblies.  The solvent did
 not remove molybdenum disulfide grease or wax:
 and did not seem to emulsify the hydraulic oil The
 full-scale test results showed Fremont 776 being
 less effective than  3-D Supreme as a cleaner.
 However, the product  performed adequately on
oils, grease and carbon soil. The major advantage
of Fremont 776 is that it can be  released to the
industrial wastewater system and  treated at the
 IWTP without modification  of the processes in
that facility.
 Orange  Sol De-Solv-lt.    When enhanced with
 agitation and elevated temperature. Orange SoU
 De-Soly-lt  is a moderately effective wax remover.
 The jar  tests  demonstrated  that  neither  ferric
 chloride nor aluminum sulfate could prevent the
 SCC sludge from floating when Orange-Sol was
 present.  For this reason. Orange-Sol should not
 be added to ihe Tinker AFB wastewater systems
 unless the oil and water separator can be shown to
 remove  the material.   Attempts to emulsify the
 Orange-Sol  in the jar tests using a high-speed
 blender were ineffective.  Being that resistant to
 emulsification speaks well for its removal by the oil
 and water separation system. A study to determine
 how De-Solve-lt effects the oil-water separatorwffl
 be conducted!.   Another  consideration is that
 Orange Sol Dc-Solve-It is expensive, S14.90 per
 gallon.

 Exam Exrate 1000. Exxatc 1000 proved moderately
 effective for removing wax and could be used in
 applications such  as  those  described for the
 Orange-Sol. Application of Exxon's Exxate 1000
 has several drawbacks.  First, floating the sludge of
 the metals  treatment system occurred,  the same
 problem as  wiith the Orange-Sol.  Concentrations
 of ferric chloride, high enough to ensure the SCC
 sludge would settle, lowered the pH to a level that
 was harmful to the activated sludge.  Unless the
 ferric chloride treatment were coupled with a pH
 adjustment downstream for the SCC, the activated
 sludge system would be upset. Low pH conditions
 would  also  shift   the  metal   precipitation
 equilibrium, raising  the concentration  of heavy
 metals downstream  from the SCC  For  these
 reasons,  the ferric  chloride  treatment is not
 recommended for use with Exxate 1000.

 Aluminum sulfate was successful in preventing the
 floatation of ithe SCC sludge, with Exxate 1000
 present  in  the waste stream, but the method is
 costly. The chemical and its handling would be
 expensive, and the amount of SCC sludge would be
 increased substantially.

 Additionally, considerations are:  the distinctive
odor  of  the solvent resulted in complaints of
 headaches and other discomfort and may require
special ventilation considerations: like Orange-Sol,
 the De-Solv-lt,  the Exxon product  is expensive,
36.24 gallon: the pilot-scale run data demonstrated
that the solvent biologically degraded and did not
disrupt the activated sludge basin operation.

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78
Bio-Tek # 140 Saf-Solv.  The Bio-Tek produa was
dropped  because   full-scale   testing  showed
inadequate cleaning of aircraft pans.
Conclusions
The major conclusions of this case study
are:
 > The Bio-Tek produa was eliminated after the
  100-galIon tank  test  due to  poor  full-scale
  cleaning efficiencies.

 • 3-D Supreme outperformed Fremont 776 in the
  cabinet spray washer tests.  The cabinet spray
  'washer operators stated that the 3-D Supreme
  cleaned better than detergents currently in use.

  The organic-based solvents.  Orange-Sol  De-
  Solv-It and Exxon Exxate 1000. were not tested
  in the cabinet washer due to explosion hazards.

  Orange-Sol proved to be the best wax remover
  in the  100-gallon tank test.  Exxate  1000 was
  also moderately effectively for wax removal.

  3-D Supreme cleaned parts very well in the full-
  scale tests, removing oil, grease and carbon well
  enough for 81  percent on the parts to pass
  normal Air  Force  inspections.    Eight-one
  percent equals  or exceeds current standards.
  One hundred percent of the parts with only oil
  and grease passed.

  When soiled with oil.  grease  and  carbon.  64
  percent of the parts cleaned with the Fremor.;
  776 passed the inspections.  The organic-based
  solvents did not  remove the  oil,  grease and
  carbon  as well as the water-based solvents.

  Twenty percent of the Orange-Sol parts and 20
  percent of the Exxate  1000 parts  passed  the
  inspections.  The organic-based solvents  did
  remove wax moderately.

  Some parts were successfully  painted  without
  blasting, a normal  paint preparation step.
                  When introduced in quantity, the Fremont 776
                  product is the only product which will not affect
                  the industrial waste treatment plant The other
                  solvents while biodegradable, require corrective
                  measures  to prevent sludge flotation, and in
                  some  cases to  initiate biodegradation in the
                  activated sludge system.

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                                                                                79
CASE STUDY #6:
REPLACEMENT OF  SOL-
VENT DEGREASING  FOR
ENGINEERING  PROTO-
TYPE PARTS, PRECISION
MACHINE PARTS, AND
VARIOUS CLEANROOM
ITEMS
At Company A, CFG-113 in a number of different
applications is  being replaced.  This  results in
annual CFC-113 reductions of 136.000 Ibs.  The
following  are  examples  of  some  of  these
operations.
Engineering Model Shop
Prototype Parts

Aqueous spray cleaning has replaced CFC-113
vapor degreasing and cold cleaning of engineering
model shop prototype pans.  A glove box spray
cabinet removes water soluble and solvent-soluble
lubricants from parts. A hand held spray wand
operating at 400 psi and a flow rate of 2J gpm
recirculates a  heated  (100ฐF)  solvent-assisted
alkaline cleaner.  Dilute concentrations of the
cleaner are used to reduce foaming.

Corrosion of the mild steel spray cabinet has been
eliminated by  the  use  of a  liner.   Slight
discoloration of some aluminum pans has occurred
because of inadequate final rinsing.

Total  equipment cost was  less  than  55,000.
Annual CFC-113 savings amount to 24,000 Ibs.
($67,200 at 1990 prices).
machine lubricants (water and solvent soluble)
using bench top ultrasonic cleaners at each work
station  has replaced sloshing pans in CFC-113
solvent.

The cleaner is maintained between 120ฐ and 14QฐF.
Cleaning time is 10 to 30 seconds at a frequency of
40 kHz. A deionized water rinse and air dry follow
the cleaning step. Emphasis is placed on thorough
rinsing and drying.

Total capital equipment cost for 75 bench top
ultrasonic units was 526,000.  Annual CFC-113
savings  amount to 86,000 Ibs. (5240,800 at 1990
prices).
Various Cleanroom Items

CFC-l 13 used in wiping and rinsing applications in
cleanrooms wan replaced with a volatile aqueous
cleaner.  The cleaner is a blend of high purity
water, isopropyl alcohol, ammonium hydroxide and
two surfactant!;.   It is  essentially 100 percent
volatile and leaves ultra-low cleaner residue. Items
cleaned include gloves, finger cots, and clean bench
work surfaces. Wet cleaning was necessary because
dry wiping and blow-off were determined to be
inadequate for the desired cleanliness level.

After nonvolatile residue testing, minor surface
tests, cleanroorn  wipe evaluation, corrosion and
electrical contact checks all showed positive results.
this technology was implemented. However, some
rusting  of  tool steel  fixtures has  occurred.
(Rusting is prevented with proper drying.)

The  cleaner is packaged  and  dispensed  in
precleaned spray bottles.   The cleaner costs
approximately SI  per gallon for materials. Annual
CFC-113 savings from this technology amounts to
26,000 Ibs. (S72..800 at 1990 prices).
Precision  Machined Parts

Ultrasonic cleaning with a solvent assisted alkaline
cleaner has replaced CFC-113 cold cleaning of
precision machined  piece  pans.  Removal of

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 80
 CASE STUDY #7:   PRO-
 GRAM TO ELIMINATE
 METHYL  CHLOROFORM
 USE  IN STEEL CHAIR
 MANUFACTURING
 OPERATIONS
 Case Study #7 is an overview of how LA-Z-BOY,
 Monroe,  Michigan,  a large  manufacturer  of
 furniture, convened a methyl chloroform vapor
 degreasing  process to a  semi-aqueous  based
 process. The company previously had used methyl
 chloroform to clean oil and metal  fines  from
 stamped carbon steel chair parts prior to painting.
 LA-Z-BOY decided to switch to a semi-aqueous
 based process using Bio T Max (a citrus terpene
 based cleaning agent). LA-Z-BOY is satisfied with
 the new semi-aqueous based cleaning process and
 has found  considerable  improvement  in paint
 adhesion compared to their old system.
 Process Description

 Installing the Bio T cleaning process  involved
 modifying the existing vapor degreaser tank so that
 it could be used as a dip tank for the wash stage.
 The capacity of this tank is  1458 gallons.  The
 rinse tank used for the semi-aqueous process is an
 old wash tank that had been previously utilized in
 the facility. The rinse tank has a capacity of 1,100
 gallons. Both the wash and rinse tanks were fitted
 with  spray nozzles and 95 gpm feed pumps to
 recirculate the water.

The wash and rinse stages are operated at room
 temperature  using DI water  as the cleaning
medium. The concentration of Bio T in the wash
tank is maintained at 8-10 percent concentration.

Pans to be cleaned are placed on  hooks on a
monorail, and undergo the following sequence of
steps (see Exhibit 18):
 •  Parts are processed through the wash and rinse
   stages. The wash and rinse cycles last about 5-
   10 minutes  depending on the level of soil
   loading and the throughput required. The time
   in the wash and rinse tanks is set by adjusting
   the speed of the monorail.

 •  Next, the parts are painted by processing them
   through a water based paint tank and a paint
   rinse tank.  Parts are painted using an electro-
   deposition process using water based  paints.
   The paint process is the same as that used with
   the old vapor degreasing process.

 •  After painting, the parts are passed through a
   dryer.  The dryer is also the same as that used
   with the old vapor degreasing process.

 •  After the parts exit the dryer, they are unloaded
   and  new  parts are loaded onto the monorail.
   The loaded parts then enter the wash stage and
   repeat the above sequence of steps.

 The semi-aqueous system is  set up so that the
 permeate from  the rinse  tank that contains the
 cany over of Bio T from the wash tank is fed back
 to the wash tank. Both tanks are made up with DI
 water to maintain the tank water level.  This is.
 necessary to make up for water loss due to drag
 out and evaporation.

 The semi-aqueous cleaning system is equipped with
 an on-line filter used to remove residue metal fines
 and chips, and  an  oil absorbent filters used  to
 remove free floating oil.  It has been noted that
 during the night when the system is shut down, oil
 separates and  floats to the top.   This  oil  is
 skimmed o'ff before the unit is turned on in the
 mornings.
Capital and Operating Costs

LA-Z-BOY estimates  that  the  capital  costs
associated with this process is 58,211.  This  is
based on costs for:

• Two sock type filtering systems (100 gpm);

• Two bottom feed pumps (3,450 rpm, 95 gpm);

• Sandblasting and painting of rinse tank;

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                                                                                                  81
 • Miscellaneous pans, pipe fittings, etc:

 • 5 drums (each 55  gallons) initial fill for  the
   semi-aqueous process; and           4  ,

 • Labor.

 LA-Z-BOY estimates  that the operating costs of
 the semi-aqueous based process is about half that
 of the methyl chloroform based process.  This is
 based of the fact that  one drum of Bio T is used
 per month.  At a cost of Si6.5 per gallon, this
 results in monthly costs of S907.5. The monthly
 cost of the solvent process was estimated at SI.836.
 This includes cost  of virgin solvent & costs of
 disposal of waste solvent. The cost calculations for
 the solvent  and  semi-aqueous process do  not
 include  energy costs  of  operating the  vapor
degreaser and the recirculating pumps respecuvcly.
 However, it is believed that the aqueous process
energy costs are  not higher  than the solvent
process energy costs.

-------
82
                         Exhibit 18

       AQUEOUS PROCESS FOR CARBON STEEL
                     CHAIR PARTS
  I
       Wash
       Tank
   Parts Load/
    Unload
Rinse
Tank
Monorail
Paint
Bath
Paint
Rinse
      Dry
      Parts
                                                Dryer
                                                    t
                                                     I
                                                     , Wet
                                                     'Parts
 I
 I


 I
 I
_L
                                                      (1S1314

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                                                               	83

                                          References


Bailey, P.A. 1977. The treatment of waste emulsified oils by ultrafiltration.  Filtration and Separation: 53-55.

Bansal. I.K. 1975. Ultrafiltration of oily wastes from process industries. AICHE Symposium Series: 93-99.

Baran. Yu,. V., A.M. Ovsyankin. V.V. Ushakov, and G.M. Franchuk.  1986. Cleaning metal surfaces with
electroaerodynamic aerosol jets.

Bhattacharyya, D., A.B. Jumawan. R.B. Grieves, and L.R. Harris. 1979. Ultrafiltration characteristics of oil-
detergent-water systems:  membrane fouling mechanisms. Separation Science and Technology, 14(6): 529-549.

Chevez, A.A., et al.  1990  (November).  Substitution of cleaners with biodegradable solvents,  phase  II,
extended performance testing.  Draft. ESL-TR-93.  Air Force Engineering and Services Center, Engineering
and Services Laboratory.                      ;

Cohen. L.E.. and J.A. Hook. 1987 (February).  Corrosion of anodized aluminum by alkaline cleaners: causes
and cures.  Plating and Surface Finishing: 73-76.

Cohen. L.E. 1987 (November)i  How clean is your 'CLEAN' metal surface?  Plating and Surface Finishing:
58-61.                                     ' ,
                                             I

Daufin. G., J.P. Labbe, and J. Pagetti.  1977. Corrosion inhibition of an aluminum-silicon-magnesium alloy
in alkaline media. Corrosion Science 17: 901-912.

Jansen. G., and J. Tervoon.  1984 (November).  Longer bath life in alkaline cleaning.  Product Finishing: 6-12.

Kaliniichuk. E.M.,  LA. Makarov.  and I.I. Vasilenko. and N.A,  Sukhovukhova.   1973.   Purification  of
petroleum-refinery waste waters by coagulation and regeneration of the coagulant sludge. Consultants Bureau:
756-761.

Lee, S.. Y. Aurella. and H.  Rogers. 1984. Concentration  polarization, membrane fouling and cleaning  in
ultrafiltration of soluble oil. Journal of Membrane Science 19: 23-38.

Unford, H.B. and E.B. Saubestre. 1950 (December). Cleaning and preparation of metals for electroplating.
Plating and Surface Finishing: 1265-1269.

Lipp, P., C.H. Lee. and CJ.D. Fell. 1988. A fundamental study of the uitrafiltration of oil-water emulsions.
Journal of Membrane Science 36: 161-177.

American Society for Metals.  1964. Metals Handbook, Volume 2.  pages 317-325.

American Society for Metals.  Surface Cleaning Finishing and Coatings, in American Metals Handbook, 9th
Edition, Volume 5.

Priest, W. 1978 (March). Treatment of waste oil emulsions by ultrafiltration. Water and Waste Treamenr. 42-
43.                                          :

Schrantz. J. 1990. Rinsing ~ a key part of pretreatment. Industrial Finishing: 24-29.

Seislowski, S.  1990 (February).  Cleaning basics part 2 - soils.  Metal Finishing: 43-46.

-------
 84



 Shukla, S.B.  1979 (June). Role of detergent raw materials. Chemical and Petro-Chemicals Journal 20-23.

 Spring, S.  1974. Industrial Cleaning.  New York: Prism Press, pages 25, 150, and  188.

 United Nations Environment Programme (UNEP). June 30,1989. Electronics. Decreasing and Dry Cleaning
 Solvents Technical Options Report.

 US. Environmental Protection  Agency.    1989a  (December).   Technical assessment of  aqueous and
 hydrocarbon/surfactant based cleaning processes in the electronics, precision instruments, and metal cleaning
 industries - Draft Report. Office of Toxic Substances.  Washington. D.C

 U.S. Environmental Protection Agency. 1989b (August). Waste minimization in metal parts cleaning. Office
 of Solid Waste. Washington, DC

US. Environmental Protection Agency. 1990 (March). Manual of practices to reduce and eliminate CFC-113
use in the electronics industry.  Office of Air and Radiation. EPA 4W/3-90-003. Washington, D.C

Wikoff. P.M.. et al.  1989 (September).  Substitution of wax and grease cleaners with biodegradable solvents:
phase I.  ESL-TR-89-04.   Air Force  Engineering and Services^Center. Eneineering and"Services  Center,
Engineering and Services Laboratory.

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                                                                                         85
             List of Vendors for CFC-113 and Methyl Chloroform
                           Solvent Cleaning Substitutes*
 Alternative Solvents
 Allied-Signal
 PO Box 1139 R
 Morristown, NJ 07960
 Tel: (201)455-4848
 Fax: (201)455-2745

 Dow Chemical
 2020 Dow Center
 Midland. MI  48674
 Tel: (517) 636-8325

 Daikin Industries. Ltd.
 Chemical Division
 1-1 Nishi Hitotsuya
 Settsu-Shi, Osaka 566
 Japan
 Tel: 81-6-349-5331

 GAP Chemicals Corporation
 1361 Alps Rd.
 Wayne. NJ 07470
 Tel:  (201)628-3847

 Aqueous Cleaners

 Ardrox
 16961 Knott Avenue
 LaMirada. CA 90638
 Tel: (714)739-2821
DuBois Chemicals, Inc.
511 Walnut Street
Cincinnati, OH 45202
Tel:  (513)762-6839
 Arco Chemical Company
 3801 West Chester Pike
 Newton Square, PA 19073
 Exxon Chemical Company
 P.O. Box 3272
 Houston. TX 77001
 Tel: (800) 231-6633

 DuPont Chemicals
 Customer Service
 B-15305
 Wilmington. DE 19898
 Tel: 1-800-441-9450
 ICI America.'; Inc.
 P.O. Box 751
 Wilmington. DE 19897
 Tel: (302) 886-4469
Brulin
2920 Dr. Andrew J. Brown. Ave.
PO Box 270
Indianapolis. IN 46206
Tel:  (317)923-3211

Freemont Industries. Inc
Valley Industrial Park
Shakopee. MN 55379
Tel: (612) 4415-4121
* This is not an exhaustive list of vendors.  For more names check the Thomas Register.  Vendors can be
cited in subsequent editions of this document by sending information to ICOLP.  ICOLP's address is provided
in Appendix A.  Listing is for information purposes only, and does not constitute any vendor endorsement by
EPA or ICOLP, either express or implied, of any product or service offered by such entity.

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  86
  Hubbard-Hali. Inc
  P.O. Box 790
  Waterbury, CT 06725
  Tel: 203-754-2171

  Modern Chemical Inc.
  P.O. Box 368
  Jacksonville, AR 72076
  Tel: (501)988-1311
  Fax: (501)682-7691

  Parker-Arachem
  32100 Stephenson Highway
  Madison Heights, MI 48071
  Tel: (313)583-9300
 W.R. Grace & Co.
 55 Hayden Avenue
 Lexineton. MA 02173
 Tel: (617)861-6600

 Aqueous Cleaning Equipment

 American Metal Wash
 360 Euclid Avenue
 PO. Box 265
 Canonsburg, PA 15317
 Tel:  (412)746-4203
 Fax: (412)746-5738

 Branson Ultrasonics Corp.
 41 Eagle Road
 Danbury, CT 06813-1961
 Tel:  (203)796^)400
Electroven Corp.
4330 Beltway Place
Suite 350
Arlington, TX 76017
Tel: (817)468-5171

Jensen Fabricating Engineers
P.O Box 362
East Berlin, CT 06023
Tel: (203) 828-6516
  Intex Products Co.
  P.O. Box 6648
  Greenville. SC  29606
  Tel: (803) 242-6152

  Oakite Products, Inc.
  50 Valley Road
  Berkeley Heights. NJ 07922
  Tel: (201)  464-6900
 Qual Tech Enterprises, Inc.
 1485 Bayshore Blvd.
 San Francisco. CA 94124
 Tel:  (415) 467-7887
 Fax:  (415) 467-7092

 3-D Inc.
 2053 Plaza Drive
 Benton Harbor. MI 49022
 Tel:  (800) 272-5326
 Bowden Industries
 1004 Oster Drive NW
 Huntsville. AL 35816
 Tel:  (205)533-3700
 Fax:  (205)539-7917
 Crest Ultrasonics Corp.
 Scotch Rd.
 Mercer County Airport
 P.O. Box 7266
 Trenton. NJ 08628
 Tel: (609) 883-4000

 Graymills
 3705 N. Lincoln Ave.
 Chicago,  IL 60613
 Tel: (312) 268-6825
J. M. Ney Company
Neytech Division
Bloomfield. CT 06002
Tel:  (203)342-2281
Fax:  (203)242-5688

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                                                                                             8T
  Stocking Inc.,
  502 Highway 67
  PO Box 127
  Kiel, WI 53042
  Tel: (414)894-2293
  Fax: (414)894-7029

  Hydrocarbon/Surfactant

  Crest Ultrasonics Corp.
  P.O. Box 7266
  Scotch Road
  Mercer County Airport
  Trenton. NJ 08628
  Tel: (609)883-4000

  DuPont Chemicals
 Customer Service
 B-15305
 Wilmington. DE 19898
 Tel: 1-800-441-9450

 Golden Technologies Company, Inc.
 Biochem Systems Division
 15000 W. 6th Avenue
 Suite 202
 Golden, CO 80401
 Tel: (303)277-6577
 Fax: (303)277-6550

 Penetone Corporation
 74 Hudson Avenue
 Tenafly, NJ 07670
 Tel: (201)567-3000
Union Camp
P.O. Box 37617
Jacksonville, Fl 32236
Tel: (904)783-2180

Alcohol Cleaning Equipment

Electronic Control Design
13626 South Freeman Road
Milwaukie, OR 97222-8825
Tel: (503)829-9108
Fax: (503)659-4422
  Unique industries
  11544 Sheldon St.
  P.O. Box 1278
  Sun Valley, CA 91353
  Tel: (213) 875-3810
  Detrex Corporation
  P.O. Box 569
  401 Emmett Ave.
  Bowling Green, KY 42102
  Tel:  (502)782-1511
 Electroven Cbrp.
 4330 Beltway Place
 Suite 350
 Arlington. TX 76017
 Tel:  (817) 468-5171

 Orange-Sol Inc.
 Dennis Weinhold
 P.O. Box 306
 Chandler. AZ; 85244
 (602) 497-8822
 Petroferm
 5400 East Coast Highway
 Fernandina Beach, FL 32034
 Tel: (904) 261-8286
 Fax: (904) 261-6994
Herbert Streckfus GmbH
Elektronik-Sondermaschinenbau
7814 Eggenstein 1
Kruppstrabe 10
Germany
Tel:  (0721) 70222-24
Telex:  7826566
Ttx:  721119
Fax:  0721/785966

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KLN Ultraschall GmbH                             Streckfuss USA. Inc.
Siegfriedstr. 124                              .       3829 W. Conflans
D-6I48 Heppenheim                                 P.O. Box 153609
Germany                                           Irving. TX 75015-3409
Tel:  6252/14-0                                      Tel: (214) 790-1614
Teletex: 625290
Fax:  6262/14-277

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                                           GLOSSARY


 Acute toxicity - The short-term toxicity of a product in a single dose: Can be divided into oral, cutaneous and
 respiratory tontines.

 Adsorption - Not to be confused with absorption. Adsorption is a surface phenomenon which some products
 can exhibit, whereby they can form a physicochemicai bond with many substances.

 Alcohols - A series of hydrocarbon derivatives with at least one hydrogen atom replaced by an -OH group.
 The simplest alcohols  (methanol, ethanol. n-propanoi, and isopropanoll) are good solvents for some organic
 soils, notably rosin, but are flammable and can form explosive mixture!, with air:  their use requires caution
 and well-designed equipment

 Aqueous cleaning - Cleaning parts with water to which may be added suitable detergents, saponifiers or other
 additives.

 Azeotrope - A mixture of chemicals is azeotropic if the vapor composition is identical to that of the liquid
 phase.  This means that the distillate of an azeonrope is theoretically identical to the solvents from which it
 is distilled. In practice, the presence of contaminants in the solvent slightly upsets the azeotropy.

 Biodegradable - Products in wastewater are classed as biodegradable  if they can be easily broken down or
 digested by, for example, sewage treatment.

 BOD — An abbreviation for biochemical oxygen demand.

 CFC - An abbreviation for chlorofluorocarbon.

 CFC-IU - A common designation for the most popular CFC solvent. 1.1.2-trichloro-l,2^-trifluoroethane,
 with an ODP of approximately 0.8.

 delation - is the solubilization of a metal salt by forming a  chemical complex or sequestering. One way of
 doing this is with ethylenediaminetetra-acetic acid (EDTA) salts which hzive a multi-dentate spiral ligand form
 that can surround metallic and other ions.

 Chlorofluorocarbon -  An organic chemical composed of  chlorine,  fluorine  and carbon atoms, usually
 characterized by high stability contributing to a high ODP.

 Chronic toxicity - The long-term  toxicity of a product in small, repeauxi doses. Chronic toxicity can often
 take many years to determine.

 COD - An abbreviation for chemical oxygen demand.

 Detergent - A product  designed to render, for example, oils and greases soluble in water, usually made from
synthetic surfactants.

Fatty acids - The principal pan of many vegetable and animal oils and greases, also known as carboxylic acids
which embrace a  wider definition. These are common contaminants far which solvents are used in their
removal. They are also used  to activate fluxes.

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 Greenhouse effect ~ A thermodynamic effect whereby energy absorbed at the earth's surface, which is normally
 able to radiate back out to space in the form of long-wave infrared radiation, is retained by gases in tne
 atmosphere, causing a rise in temperature. The gases in question are partially natural, but man-made pollution
 is thought to increasingly contribute to the effect The same CFCs that cause ozone depletion are known to
 be 'greenhouse gases", with a single CFC molecule having the same estimated effect as 10,000 carbon dioxide
 molecules.  ,

 HCFC — An abbreviation for hydrochlorofluorocarbon.

 HFC - An abbreviation for hydrofluorocarbon.

 Hydrocarbon/surfactant blend - A mixture of low-volatile hydrocarbon solvents with surfactants, allowing the
 use of a two-phase cleaning process. The first phase is solvent cleaning in the blend and the second phase is
 water cleaning to remove the residues of the blend and any other water-soluble soils.  The surfactant ensures
 the water-solubility of the otherwise insoluble hydrocarbon. Terpenes and other hydrocarbons are often used
 in this application.

 Hydrochlorofluorocarfoon - An organic chemical composed of hydroccn. chlorine, fluorine and carbon atoms.
 These chemicals are less stable than pure CFCs. thereby having generally lower ODPs..

 Metal cleaning - General cleaning or dcgreasing of metallic componcn ts or assemblies, without specific quality
 requirements or with low ones.

 Methyl chloroform - See  1,1,1-trichloroethane.

 ODP — An abbreviation for ozone depletion potential.

 Ozone — A gas formed when oxygen is ionized by,  for example,  the action of ultraviolet light or a strong
 electric field.  It  has  the  property of blocking the  passage of dangerous wavelengths of ultraviolet light
 Whereas it is a desirable gas  in the stratosphere, it is toxic to living  organisms at ground level (see volatile
 organic compound).

 Ozone depletion - Accelerated  chemical destruction of the stratospheric ozone layer by the presence of
 substances produced, for the most part, by human activities.  The  most depleting species for the ozone layer
 are the chlorine and bromine free radicals generated from relatively stable chlorinated, fluorinated, and
 brominated products by ultraviolet radiation.

 Ozone depletion potential ~ A relative index indicating the extent to which a chemical product may cause
 ozone depletion. The reference level of 1 is the potential of CFC-11 and CFC-12 to cause ozone depletion.
 If a product has an ozone depletion potential of 0.5, a given weight of the product in the atmosphere would,
 in time, deplete half the ozone that the same weight of CFC-11 would deplete.  The ozone depletion potentials;
 are calculated from mathematical models which take into account factors such as the stability of the product,
 the rate of diffusion, the quantity of depleting atoms per molecule, and the effect of ultraviolet light and other
 radiation on the molecules.

 Ozone layer - A layer in the stratosphere, at an altitude of approximately 10-50 km, where a relatively strong
concentration of ozone shields the earth from excessive ultraviolet radiation.

Saponider - A chemical designed to react with organic fatty acids, such as rosin, some oils and greases etc,
in order to form a water-soluble soap. This is a solvent-free method of defluxing and degreasing many pans.
Saponifiers are usually alkaline and may be mineral (based on sodium hydroxide or potassium hydroxide) or
organic  (based on water solutions of monoethanolamine).

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Solvent - Although not a strictly correct definition, in this context a product (aqueous or organic) designed
to clean a component or assembly by dissolving the contaminants present on its surface.

Surfactant — A product designed to reduce the surface tension of water.  Also referred to as tensio-active
agents/tensides.  Detergents are made up principally from surfactants.

Terpene — Any of many homocyclic hydrocarbons with the empirical formula CTOH16, characteristic odor.
Turpentine is mainly a mixture of terpenes. See hydrocarbon/surfactant blends.

Volatile organic compound (VOC) ~ These are constituents that will evaporate at their temperature of use
and which, by a photochemical reaction, will cause atmospheric oxygen to be converted into potential smog-
promoting tropospheric ozone under favorable climatic conditions.

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                                                                                        93
                                   APPENDIX A

                        INDUSTRY COOPERATIVE
                 FOR OZONE  LAYER  PROTECTION
The  Industry  Cooperative  for  Ozone  Layer
Protection (ICOLP) was formed by a group of
industries to protect the ozone layer. The primary
role of ICOLP is to coordinate the exchange of
non-proprietary   information  on   alternative
technologies,  substances,   and   processes   to
eliminate ozone-depleting solvents.  By working
closely  with solvent users, suppliers, and other
interested organizations worldwide, ICOLP seeks
the widest and most effective dissemination of
information  harnessed  through  its  member
companies and other sources.                •
   ICOLP corporate members include:

      AT&T
      Boeing Company
      British Aerospace
      Compaq Computer Corporation
      Digital Equipment Corporation
      Ford Motor Company
      General Electric
      Hitachi Limited
      Honeywell
      IBM
      Matsushita Electric Industrial
        Company
      Mitsubishi Electric Corporation
      Motorola
      Northern Telecom
      Sundstrand
      Texas Instruments
      Toshiba Corporation
In addition. ICOLP has a number of industry
association and government organization affiliates.
Industry association affiliates include American
Electronics   Association   (AEA),   Electronics
Industries   Association,  Japan   Electrical
Manufacturers  Association  and  Halogenated
Solvents Industry Alliance (U.S.).  Government
organization  affiliates include the City of Irvine,
California, the State Institute of Applied Chemistry
(U.S.S.R.'), the Swedish National Environmental
Protection Agency, the U.S. Air Force, and the
U.S. Environmental  Protection  Agency (EPA).
The American  Electronics  Association,  the
Electronic Industries  Association, the City of
Irvine.   California,  the   Japan   Electrical
Manufacturers Association, the Swedish National
Environmental  Protection Agency, the U.S. EPA,
the U.S. Air Force, and the U.S.S.R. State Institute
of  Applied   Chemistry  have  signed  formal
Memorandums  of Understanding with ICOLP.
ICOLP  will  work  with  the  U.S.  EPA  to
disseminate  information  on technically feasible,
cost effective,   and   environmentally  sound
alternatives for  ozone depleting solvents.

ICOLP is also working with the National Academy
of Engineering  to hold a series of workshops to
identify promising research directions and to make
most efficient use of research funding.

The goals of ECOLP are to:

•  Encourage  the prompt  adoption  of safe,
   environmentally  acceptable,  nonproprietary
   alternative  substances,   processes,  and
   technologies to replace current ozone-depleting
   solvents;

•  Act  as  an  international  clearinghouse  for
   information on alternatives;

•  Work with  existing  private,  national,  and
   international trade groups, organizations, and

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  94	      •

    government bodies to develop the most efficient
    means of creating,  gathering, and distributing
    information on alternatives.

  One  example  of  ICOLP's  activities  is  the
  development  and support  of an  alternative
  technologies  electronic  database  "OZONET.'
  OZONET is accessible worldwide and has relevant
 information on the alternatives to ozone-depleting
 solvents. OZONET not only contains technical
 publications, conference papers, and reports on the
 most recent developments of alternatives to the
 current uses of ozone-depleting solvents, but it also
 contains:

 • Information  on   the   health,   safety  and
   environmental effects of alternative chemicals
   and processes:

 • Information supplied by companies developing
   alternative chemicals and technologies;

 • Names, addresses, and telephone numbers for
   technical   experts,   government   contacts,
   institutions  and associations,  and  other key
   contributors to the selection of alternatives;

•  Dates and places of forthcoming conferences,
   seminars,  and workshops;

•  Legislation that has been enacted or is in place
   internationally, nationally, and  locally.

Information about ICOLP can be obtained  from:

   Mr. Steven B. Hellem
   Executive  Director
   ICOLP
   1440 New York Avenue, N.W.
  Suite 300
  Washington, D.C 20005
  Tel:  (202)737-1419
  Fax:  (202)639-8685

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