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<£ 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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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.
» 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 240°F, 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.
-------
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).
-------
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
-------
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
-------
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
-------
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
-------
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
-------
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;
-------
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*cycJ«
Clsamd
Parts
TrMtmtntor
T)DU»ettoOr«in
Decanter
-------
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 20-30°F 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 -30° to -20°F;
• Dehumidification condenser operating at -30 to
-20°F (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)
Vi5co«rty (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" "*"«»«"«"• recommend., blend of HCFC-Ulb/HCFC-
*" "" •r*Ctrop- °* 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
£2.
# t •
Dehumidifier Coll
-20° 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)
-20° F to-40° F
Main Condensor
35° 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 (20°C)
Viscosity (25"C)
Specific Gravity
Interfadal Surface Tension (25°C)
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
-24.4°C (-11.9°F)
202°C (395°F) @ 760 mm
• 0.29 mm
1.65 cp
1.027
40.7 dynes/cm
95°C (204°F)
93°C (199°F)
0.058 grams/filter - lower limit
2.18% vapor in air - JWF (182°C)
0323 grams/liter - upper limit
1234% vapors in air - 370°F (188°Q
719 K cai/mol
0.40 K cal/kg at 20°C
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 °F.
20 to 30 Psig.
SPRAY WASH CLEANING
(Spray under immersion recommended.)
Rinse Tanks
1 mm.
30 sec. ']
Daionized Water.
120°F.12Psig
Drying
Forced
Hot Air
or
• Vacuum.
IMMERSION TANK CLEANING
. Cleaning Tanks
WrWVWV
1-3 min..
WrWWW
rWrWrWV
WrWVWr
NMP
Ambient to 180° F.
With or without Ultrasonics
Rinse Tanks
1 min.
1 min;
Deionized Water.
200° F.
Drying
Slow Pull®
or Capillary
Drying.
Forced Hot
Air.
0 May be spray rinsed.
© 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 40°C (104°F) 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 15°C (27°F) 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
15°C 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.
60»F
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 0°F) 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
11£17
114.14
114.18
114.18
116.16
lb»
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 ©
68*F
In Water
•
26.8
3.4'°* f
4.3
2.3
2.0
M77"'
02.
•
0.6
0.4
«
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. @
68»F
Btu/(lb)(*F)
0.51
0.53
0.56
.
0.49
0.55
0.55
0.44"-'
.
.
.
O-SO**'
Latent
Heat
<§>
B.P.
Btu/16
224
191
163
180
»
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
3M»J 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
-------
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
25«*
None
X
Methylene
Chloride
-0
CH2Cl2
84.9
39.4-40.4
1.33 •
N/A
132
Medium
500*
None
-------
52
-------
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."
-------
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.
-------
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,
-------
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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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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Wastewater
Holding
Tank
i '
Enhanced
Gravity •£
Separator ^
Exhibit 17
SEMI-CONTINUOUS WASTEWATER
TREATMENT PROCESS
-> Ultra- _p
•^ Rltration £
\ \
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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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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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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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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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 14Q°F 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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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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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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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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• 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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180°F: 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 135°F. 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 135°F. 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
135°F 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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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 (100°F) 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 120° and 14Q°F.
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.
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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
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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-
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Chevez, A.A., et al. 1990 (November). Substitution of cleaners with biodegradable solvents, phase II,
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Cohen. L.E.. and J.A. Hook. 1987 (February). Corrosion of anodized aluminum by alkaline cleaners: causes
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Cohen. L.E. 1987 (November)i How clean is your 'CLEAN' metal surface? Plating and Surface Finishing:
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I
Daufin. G., J.P. Labbe, and J. Pagetti. 1977. Corrosion inhibition of an aluminum-silicon-magnesium alloy
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Jansen. G., and J. Tervoon. 1984 (November). Longer bath life in alkaline cleaning. Product Finishing: 6-12.
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Schrantz. J. 1990. Rinsing ~ a key part of pretreatment. Industrial Finishing: 24-29.
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Shukla, S.B. 1979 (June). Role of detergent raw materials. Chemical and Petro-Chemicals Journal 20-23.
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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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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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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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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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