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I.   Introduc t ion




     Subtitle  C  of  the  Solid  Waste Disposal Act, as amended




by the Resource  Conservation  and Recovery Act of 1976 creates




a comprehensive  "cradle-to-grave" management control systea




for the disposal of  hazardous waste designed to protect the




public health  and the  environment from the improper disposal




of such waste.   Section  3001  of  that Subtitle requires EPA to




identify the  characteristics  of  and list hazardous wastes.




Wastes identified or listed as hazardous will be included in




the management control  system created by Sections 3002-3005




and 3010.  Wastes not  identified or listed will be subject to




the requirements for non-hazardous waste imposed by the States




under Subtitle D.  The Agency has determined that reactivity




is a hazardous characteristic because improperly managed




reactive wastes  (i.e., explosives, etc.) pose a substantial




present or potential danger to human health and the environment




The purpose of this  document  is  to explain the Agency's




definition of  reactive wastes, to discuss the comments received




on the proposed  definition of reactive waste (43 FR 58956,




December 18,  1978) and  the changes subsequently made.




I1.  Proposed  Regulation




     Reactive  waste.   (1) Definition - A solid waste is a




hazardous waste  if a representative sample of the waste:




     (i)  Is normally unstable and readily undergoes violent




chemical change without  detonating;  reacts violently with




water,  forms potentially  explosive mixtures with water, or




generates toxic  gases, vapors, or fumes when mixed with water;
                              -2-

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or is a cyanide or  sulfide bearing waste which can generate



toxic gases, vapors, or fumes when exposed to mild acidic or



basic conditions.



     (ii) Is capable of detonation or explosive reaction but



requires a strong initiating source or which must be heated



under confinement before initiation can take place, or which



reacts explosively  with water.



     (iii) Is readily capable of detonation or of explosive



decomposition or reaction at normal temperatures and pressures



     (iv) Is a forbidden explosive as defined in 49 CFR



173.51, a Class A explosive as defined in 49 CFR 173.53, or a



Class B explosive as defined in 49 CFR 173.58.





     NOTESuch waste includes pyrophoric .substances,



     explosives, autopolymerization material and oxidizing



     agents.   If it is not apparent whether a waste is a



     hazardous waste using this description,  then the



     methods cited below or equivalent methods can be used



     to determine if the waste is hazardous waste.





     Identification method.  (1)  Thermally unstable waste



can be  identified using the Explosion Temperature Test cited



in Appendix II of this Subpart (waste for which explosion,



ignition,  or decomposition occurs at 125C after 5 ninutes is



classed as hazardous waste).



     (i)   Waste unstable to mechanical shock can be identified



using the Bureau of Explosives impact apparatus and the tests



cited in  49 CFR 173.53 (b), (c), (d),  or (f),  as appropriate.





                             -3-

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Ill. Rationale for Proposed Regulation



     A.   Rationale for proposing a reactivity characteristic






     Reactivity was chosen as a characteristic of hazardous



waste because improperly managed reactive wastes present a




danger to human health and the environment.  By definition,



reactive wastes are those which are capable of violently



generating heat and pressure, reacting vigorously with air or




water, reacting with water to generate toxic fumes, etc.  The



dangers which these wastes pose to transporters, waste disposal



personnel, and the public are thus for the most part obvious.




In the past, there have been a number of incidents of damage



to persons or property which have resulted from the improper



management of reactive wastes.  Some of these damage incidents




are listed and discussed in Appendix I.



     Because of their acknowledged danger, reactive materials



are often controlled by federal and state regulations and




suggestions for their safe use or management are often



published by public or private organizations.  Some of these




federal and state regulations and the guidelines for reactive



materials prescribed by the National Fire Protection Association



(NFPA) are listed and discussed in Appendix II.



     B.   Rationale for proposed reactivity definition




     Reactive substances can be described as those which:



     1)   autopolymerize



     2)   are unstable with respect to heat or shock




     3)   are explosive






                             -4-

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      4)    are strong oxidizers




      5)    react vigorously with air or water




      6)    react with water to generate toxic  fumes






      As  can  be seen from this description, the  tern  "reactivity"




 encompasses  a diverse and somewhat loosely conjoined  class  of




 physical  properties or effects.   These effects  are not  mutually




 exclusive  and a particular substance might exhibit several  of




 the properties mentioned above.   For instance,  certain




 peroxides  would fall into four of the above six  categories.




 Additionally,  these categories overlap not only  with  each




 other, but also with the other characteristics.  For  example,




 the difference between flammabi1ity (conflagration)  and  ex-




 plosiveness  (deflagration)  is only one of degree --  an  illustra-




 tion  of the  fact  that the properties embraced by the  term




 "reactivity"  are,  like the term  "reactivity" itself,  relative




 properties which  have meaning only in a relative sense.




      The Agency has attempted where possible to  define




hazardous waste characteristics  in terms  of specific,




numerically  quantified properties measurable by  standardized




 and available  testing protocols.   This has proven difficult




in the case  of  reactive  wastes.   The first problen vith




constructing  a  numerically  quantified  definition cf  reactive




wastes arises  from  the fact  that  the term "reactivity" ecbraces




a wide variety  of different  (though overlapping) effects,




each  of which  can be  triggered by an equally wide variety of




initiating conditions  or  forces.   It would be cumbersome, if




not completely  impractical,  to construct  a numerically




                              -5-

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quantified definition which  included all these different

effects  and their potential  initiating  forces.  The second

problem  arises  from the  fact, as noted  above, that the

properties embraced by the term reactivity are relative

properties.  The determination that something "reacts vigorously

with air or water" or is  "unstable with respect to heat or

shock" is a relative determination, not an absolute one.  The

effects  being measured proceed along a  continuum.  Thus, it

is difficult to draw the  line at any particular point.

     These problems are  reflected in the testing methods

which might be used to identify reactive substances.  These

methods  suffer  from the  following generic deficiences:

     1.   The available tests are too specific and do not
          reflect the wide variety of waste management
          conditions.

     The available tests  are used to determine how a specific

aspect or manifestation of waste reactivity behaves under a

special  and specific type of stress.  For example, DTA

(Differential Thermal Analysis) measures how the rate of

temperature rise of the waste (one specific aspect of waste

reactivity) correlates with the slow input of thermal energy

(one special and specific type of stress).  This would not

indicate how the waste reacts to mechanical shock (a drop

test would be necessary to determine that), electrical shock,

whether  the waste is a strong oxidizer, or even what is

producing the rate of temperature change (pressure buildup,

toxic or nontoxic fumes,  heat of mixing, etc.).   The information

derived  from the available tests,  then, is too specialized
                             -6-

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and does not reflect the wide variety of stresses and initiating

forces likely to be found in a disposal environment.

     2.   Reactivity of a sample may not reflect reactivity of
          the whole waste:

     In the case of wastes which are thermally unstable, the

reactivity of the sample may not adequately reflect the

reactivity of the whole waste.  The kinetics of reaction are

not only a function of the available initiating sources and

ambient temperature, but are also a function of the mass,

configuration,  geometry, etc. of the sample.  For a "runaway"

reaction to occur, the system must transcend that steady

state where the energy (heat) produced by reaction is equal

to the energy transferred to the surroundings from the re-

acting mass.   When this critical temperature is reached, the

mass experiences catastrophic self-heating.  This heat

transfer phenomena is a function of sample size, density, and

geometry.   As demonstrated in equation 1:^

     Cdt/dt - QVp exp (-E/RT) + hS (T - To)       (1)

     C = me (m=mass and c = specific heat)

     T = Temperature of the material

     Q = Heat of decomposition

     V = Volume

     p = Density

     E = Activation energy

     R = Gas  constant

     h => Heat transfer coefficient

     S = Surface are of the material
                             -7-

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 As  can be  seen  from  this  equation the rate of temperature

 rise will  be affected both by the intensive properties of the

 waste, such as  density, and  the extensive properties of the

 waste, such as.  surface area  and geometry.  Since the extensive

 properties of the  sample  are likely to be different from the

 extensive  properties of the whole waste, the reactivity of

 the sample may  not reflect the reactivity of the whole waste.

     3.    The test results are in most cases subjective or
           not directly applicable.

     The ideal  test  to use in a regulatory program is usually

 one which requires minimal interpretation.  The majority of

 available  reactivity testing methods are not of the "pass-

 fail" type.  Rather, these testing methods usually produce

 test results which consist of a first order differential

 plotted against time or against a standard, from which relative

 reactivity can be assessed.  When a test of this sort is run,

 it is not run to determine "reactivity" per se but rather to

 elicit information concerning how "fast" a material reacts

 (i.e.  kinetic information) or how vigorously it reacts (thermo-

 dynamic information).  Thus,  the decision as to whether a

waste is reactive requires subjective interpretation of the

 test results.

     Additionally,  the information derived from such tests

may not be directly related to reactivity.  For example, the

test results might provide information on the activation

energy - a useful,  but potentially misleading bit of information

since it reflects the speed of the reaction rather than the
                             -8-

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 reaction's  effects.   The  inapplicability of some of the test

 results  emphasizes  the  indefinite  meaning of the term

 "reactivity",  a  term  which  draws  its  meaning from the context

 of  its use.  A chemist  might  think of a  "reactive" substance

 as  one with  a  small activation  energy (the energy difference

 between  the  reactive  substance's  initial and transition

 states),  i.e., one which  reacts  easily.   The Agency,  however,

 unlike the hypothetical chemist,  is  not  just interested in

 things that  react "easily"  but  also  in things  which react

 vigorously.  It  consequently  needs  to take into  account not

 just the  activation energy  of a  substance but  also the  heat

 of  reaction, the molecularity of  the  reaction  and other

 factors  - information which the  available tests  often do not

 supply.   It  is,  in other words,, not  really interested in

 performing a thermodynamic  measurement,  but  rather in observing

 if  a waste behaves in such  a  way  as  to pose  a  danger  under

 normal handling  conditions.

     4.   The  standardized  methods  that  do exist  were not
          developed for waste testing.

     Use  of  the  available testing  methods on waste materials

 often results  in the  application of  standardized  methods to

 non-standardized samples and  the application of  standardized

methods  to samples with physical consistencies the method  was

not designed for.  If such methods  are used, there suits

might be difficult to interpret with  certainty.

     The avai lable reactivity testing methods  are  individually
                             -9-

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 described  and  evaluated  in Appendix  3*.  As is evident from

 those  specific evaluations and  from  the preceeding discussion

 of  the generic shortcomings of  the available testing methods,

 none of these  "type" methods are suitable  for use to

 unequivocally.determine  if a waste presents a reactive hazard.

 For essentially the same reasons, a  numerically quantified

 definition of  reactive waste is not  feasible.  This is not as

 big a  problem  as might be thought on initial reflection.

 Most generators whose wastes are dangerous because they are

 reactive are well aware  of this property of their waste.

 Reactive wastes present  special problems in handling, storage

 and transprot.  Also, reactive wastes are  rarely generated

 from unreactive feed stocks or  in processes producing unreactive

 products or intermediates.  Furthermore, the problems posed

 by  reactive wastes appear to be confined to a fairly narrow

 category of wastes.  The damage incidents  show that the major

 problems seem  to be the  formation of hydrogen sulfide (H2S)

 from either soluble sulfides or biological degradation of

 sulfur  containing wastes, the formation of hydrogen cyanide

 (HCN)  from soluble cyanides,  and the explosion of some
*These evaluations are taken from "A Second Appraisal of
Methods for Estimating Self Reaction Hazards", E. D. Domalski,
Report No. DOT/MTB/OHMD-76-6,"Classification of Test Methods
for Oxidizing Materials", V.M.  Kuchta,  A. C. Furno,  and
A. C. Imof, Bureau of Mines, Report of Investigations 7954 and
"Classification of Hazards of Materials-Water Reactive Materials,
and Inorganic Peroxides", C. Mason and V. C. Cooper, NTIS No.
PB 209-422.  The evaluations are slightly modified so as to
determine applicability of test methods to waste materials.
                             -10-

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 "unidentified"  waste  material.   It  will  thus  only be in a

 rare  instance  that  a  generator  would  be  unsure  of the reactivity

 class  of  the waste, or  would  be unable  to  assess  whether the

 waste  fits  a prose  definition,  ,and  would require  the application

 of  testing  protocols  to determine  the reactivity  of  this

 waste.  Since  the available testing methods  are not  ideal

 for identifying  those wastes  categorized as  hazardous due to

 reactivity, the  approach  chosen is  to prescribe a prose

 description of  reactive waste for  self-determination by

 generators  and  to list  wastes which meet this description and

 have been identified  as  reactive.

     The  prose  definition  chosen is a paraphrase  of  the top

 three  of  the reactive classes of the  National Fire Protection

 Association (.NFPA)  reactivity classification  system.   The

 other  two classes in  the NFPA c1 assificat ion  scheme  are not

 included  since  these  would include  materials  which are  inert

 under  normal handlingconditions.   This  definition is used

 because it includes all  aspects  and types  of  reactivity which

 present a danger* and is already familiar  to  persons  handling

 reactive materials.    The Chemical Manufacturers Association^-

 uses this definition  to  classify reactive  wastes  in  its

 "Laboratory Waste Disposal Manual".   Also, a  paraphrase of

 this classification system is used  by the  Navy2 in. their

hazardous waste disposal guide  and  is used in other  hazardous

materials handling guides^>^ as  a classification  system.
*A11 wastes which have been identified as having caused
 damage are identified under this definition as are  all
 commonly defined types of reactivity.

                             -11-

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Furthermore, the States of California and Oklahoma use this



system to define reactive wastes.
                             -12-

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                          References
1.   "Laboratory Waste Disposal Manual" Chemical Manufacturers
     Association (1975).

2.   "NEPSS Hazardous Waste Disposal Guide", Naval Environ-
     mental Protection Support Service (1976).

3.   "Handling Guide for Potentially Hazardous  Materials",
     Material Safety Management Inc. (1975).

4.   Material Data Safety Sheets.

5.   E.  J. Domalski, "A Second Appraisal of Methods for Estimating
     Self-Reaction Hazards", DOT/MTB/OHHO-76/6,  G.P.O.  (1976).
                             -13-

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 IV.  Comments Received on the Proposed Characteristics
     and the Agency's Response to These Comments

     The Agency received approximately forty comment letters

 addressing reactivity.  These letters contained approximately

 sixty discrete recommendations or comments on the proposed

 regulation (in some letters more than one point was addressed).

 Several of the commenters felt that the proposed reactivity

 definition was adequate and provides desirable flexibility

 for the generator to use judgement.  However, the large

majority of comments expressed concern with the Agency's

 reactivity characteristic.  These comments have been categorized

by either content or the portion of the regulation addressed.

A discussion of these follows:


A.   A large majority of the comments dealt with the asserted

lack of specificity and ambiguity of the prose definition.

     0  A number of commenters argued that the prose definition

       employed by the Agency is, as a general matter,  too

       vague and should be replaced by a numerically quanti-

       fied definition accompanied by appropriate testing

       protocols.   This comment has been fully addressed in

       Part III above and need not be addressed further here.



     0  A number of commenters argued that the inclusion in

       the definition of wastes which "generate toxic gases,

       vapors,  or  fumes when mixed with water" and of "cyanide

       or sulfide  bearing wasteCs] which can generate toxic

       gases,  vapors,  or fumes when exposed to mild acidic


                             -14-

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or basic conditions" needs to be made more specific.




Several of the commenters suggested that a phrase



such as "in harmful quantities" be inserted into the



proposed regulations as follows: "...or generates




toxic gases, vapors, or fumes in hamful quantities



when mixed with water"; "or is a cyanide or sulfide



bearing waste which can generate toxic gases,  vapors,




or fumes in harmful quantities when exposed to mild



acidic or basic conditions."  The comments on the



cyanide and sulfide bearing wastes all pointed out




that everything contains sulfides and most things



contain cyanides (albeit in trace amounts) and many



of these can generate minute quantities of hydrogen



sulfide or hydrogen cyanide under mildly acidic or



basic conditions.  The Agency is sympathetic to these



concerns,  and, in anticipation of such problems, had



attempted to make clear in the preamble and background



documents that the Agency Was leaving the determination



of reactivity hazard up to the reasonable judgement



of the generator based upon the generator's past



experience with.the waste.   Taking this conmon sense



approach,  such material as soil or flyash with sulfides




contamination (examples of sulfide and cyanide bearing



wastes supplied by the commenters) would clearly not



meet the reactivity definition.  Despite this, the




point made by the commenters is certainly valid.  There-



fore, so that there will be no confusion, the  Agency has






                      -15-

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  changed the final regulation to make it more specific,  as




  follows:  "...or generates toxic gases, vapors  or fumes:




  in quantities sufficient to present a danger to public



  health or the environment when mixed with water; or is  a




  cyanide or sulfide bearing waste which can generate toxic




  gases,  vapors or fumes in quantities sufficient to present a




  danger to public health or the environment when exposed..."




  This would certainly better reflect our regulatory intent.








e A number of commenters advocated that the Agency specify



  what is meant by mildly acidic or basic conditions.   One




  commenter specified a pH range (5 to 9),  but offered no



  rationale as to  why this particular range should be used.




  Since a substantal percentage  of the commenters found the




  phrase  "mildly acidic or basic"  to be rather nebulous,  the



  Agency  has decided that a specific pH range should be speci-



  fied.   The pH range chosen is  that which  is considered  non-



  hazardous by the  corrosivity characteristic (2  <  pH <12.5).



  This range was chosen because  any liquid  outside  the range



  is hazardous and  requires  management within the Subtitle  C



  regulations.   Only liquid  wastes  inside this  range can  be



  landfilled without regard  to the  strictures  on  compatibility



  imposed by the Subtitle  C  regulations  and co-disposed with




  wastes  containing  soluble  cyanides  or  sulfides.   These  are



  then the most stringent  pH conditions  which a waste  could be



  subjected to outside  of  a  Subtitle  C facility.   (Natural



  waters  are unlikely  to be  outside  this  pH range).






                        -16-

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0 Several commenters suggested that the definition of



  cyanide bearing waste should distinguish between "free



  cyanide" and ferro cyanide" since the latter would not




  be available to generate hydrogen cyanide under mild




  acidic or basic conditions.  The Agency beleives that



  such a clarification is not necessary.   If the cyanide




  is unavailable under the specified acidic or basic



  conditions then toxic hydrogen cyanide fumes.cannot be



  generated and the wastes containing these unavailable




  cyanides are not reactive.   To specify these as exemp-



  tions would be redundant and by implication might lead



  generators to conclude that other unavailable sulfides




  or cyanides NOT specifically exempted,  do meet the



  reactivity characteristic.








0  A number of commenters advocated specifying the concen-



  tration of sulfide or cyanide needed to make cyanide



  or sulfide bearing wastes hazardous.  As explained above,




  the identity of wastes which generate toxic gases under



  the conditions specified in the Definition should be



  obvious to the generator and thus,  this level of sophi-




  stication is unnecessary.








0  One commenter suggested that the Agency specify a



  rate of evolution of toxic  gas,  but included no sugges-



  tions as to how to do so.  The Agency is unsure of how



  a laboratory test method measuring  gas  evolution rate






                        -17-

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        could be developed which could then be meaningfully

        related to field conditions.  Therefore, an evolution

        rate of toxic gas will not be included in the final

        regulat ions.



        One comtnenter argued that sulfides and cyanides should

        not be singled out in the regulations and further

        stated that all other potential toxic fume generators

        be  included or, alternatively, that no toxic fume gen-

        erators be  included.   The Agency  disagrees.   According

        to  information which  the Agency has in its possession

        (see  Appendix I),  the primary vastes  implicated in the

        generation  of toxic  gas  are  sulfides  and cyanides.  Thus,

        the Agency  would  be  remiss  if it  did  not specify thase

        types  of wastes.   If  others  are identified,  they will

        be  included also.


B.   A  number  of commenters  argued  that  the  test protocols

proposed in  Section  250.13  (c)(2)  of the  regulations  were

expensive, unreliable  and not specific enough.   Additionally,

several other  commenters had  problems  with specific  test

protocols.   (For instance, some  commeaters argued  that  the

125C temperature  adopted for the Explosion Temperature Test

was not a  reasonable  temperature and that  decomposition,  as

used in this test, needs to be defined.)

     As a  result of  some preliminary work  undertaken  by the

Agency on  the Explosion Temperature  Test*  and  after  revieving
*Evaluation of Solid Waste Extraction ?rocedures  and  Various
 Hazard Identification Tests  (Final Report)",  NUS  Corporation,
 September, 1979, (see Appendix IV).

                              -18-

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 the  comments  received  on these test protocols* (and in view of the

 generic  problems  with  such  tests,  discussed above and in Appendix

 III),  the  Agency  has  decided  to remove the test protocols from

 261.23  of the  regulations.   The Agency agrees in general that

 they  are are  unsuitable  in  defining a "reactive" waste for RCRA

 regulatory purposes.   The Agency has accordingly removed the des-

 ignated  test  protocols  from  the regulations except to the extent

 that  the Department  of  Transportation's definition of Class A

 explosiv.es -requires  use  of  the shock instability test.  As a result

 of this  decision,  the Agency  does  not believe it is necessary to

 discuss  the individual  concerns on the various test protocols.


 C.    A number of  commenters  argued that only under landfill con-

 ditions will  a  waste be  subjected  to strong initiating sources

 or heated  under confinement.   Therefore,  they stated that since

 no landf.illing  of  explosive waste  is permitted, these conditions

 will  never occur  and Section  250.13(c)(1) (ii ) is unnecessary.

      This  argument is completely circular.   If Secti'on 250.13

 (c)(l)(ii) were removed  from  the regulations, explosive wastes

 would not  be  considered  hazardous  and could be disposed of in

 a sanitary landfill, thus subjecting the  wastes to the very

 conditions which  the commenters contend will cause the waste

 to explode.   In any event, the'Agency.does' not agree that a

 landfill is the only place in  which strong  initiating forces
*Comments were received from.the  public  on  the  proposed
 reactivity test protocols both during  the  90-dav  comment
 period on the proposed 3001 regulations  (43 FR 58956) and
 in response to the solicitation  of  corn-merits  on the  NUS report
 (Evaluation of Solid Waste Extraction  Procedures  and Various
 Hazard Identification Tests) which  was  noticed in the Federal
 Register on December 28, 1979. (44 FR 75827-76828)

                             -19-

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or heating under  pressure  can  occur.   Pressure  increase  can




be caused by  confinement  (e.g.,  a  drum)  together  with




temperature increase  (e.g.,  caused  by  mixing) or  gas  generation




(e.g., desolubilization of  gases or  deconposit ion into  gases).









D.  A number  of commenters  advocated exempting  emergency




situations (i.e., homemade  bombs)  from coverage of  RCRA  so




that emergency  teams  can dispose of  these  explosive materials




as expeditiously  as possible without delay  (i.e.,  without




requiring a manifest, etc.).




     The regulation already makes  accommodation for cases of




imminent hazard in 263.30.  Thus,  emergency handling of




explosive wastes would be exempted  by  this  section.









E.  Other Comments




       A number of commenters  advocated  that all  the character-




       istics  be made as flexible as the reactivity character-




       istic.




       The Agency disagrees with these comments;  the broad




       meaning and generic character of  the reactivity "uni-




       verse"  requires a flexible characteristic.   The Agency




       would  have preferred to define,  reactivity  by specific




       test  protocols.  However, this  is not possible.  The




       other  characterisitics, (except ignitable  solids) can




       be delineated  or  gauged by measurement of  one (or a




       few)  specific  chemical/physical properties; therefore,




       the  Agency will continue to  define the ignitable,




       corrosive,  and toxicity characteristic as  proposed.






                             -20-

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 0 One commenter argued that just because a waste may




  undergo a violent chemical change with another waste



  is no reason to consider a waste hazardous.  To illu-



  strate this point, the commenter pointed out that an




  acid and base when mixed will undergo violent chemical



  change, but that such mixing (neutralization) is a



  necessary part of many treatment systems and should




  not be prohibited.



  The Agency believes this commenter to be under a mis-



  apprehension about the scope of the reactivity defi-




  nition.  The definition of reactivity refers to wastes



  which undergo violent change in an uncontrolled raanner



  either by themselves, or when mixed with water.  There-



  fore,  the example of neutralization given by the commente;



  is inappropriate, in as much as that example involves the



  mixing of wastes.  Furthermore, the Agency does not




  believe that the example given by the commenter is a fair



  representation of the hazards posed by wastes capable



  of undergoing a violent chemical change.   The example




  given involves the controlled interaction between two



  wastes which is a treatment  technique and thus does not



  reflect the hazards presented by uncontrolled violent




  chemical change characteristic of waste management



  situations.








0 One commenter suggested that the definition of reactive



  waste  be subdivided into sections which might be later






                        -21-

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 indexed  into a  compatibility  chart.




     The  primary  purpose  of  Section  3001 is  to identify




 hazardous  wastes,  and  not  to  dictate  management  tech-




 niques.  Section 3004  will  address  the various management




 techniques  including  incompatible wastes  (see 265.17




 of  the regulations).   An appendix to  the  regulations




 (Appendix  5  in Part 265) is provided  with just such  infor-




 mat ion.






 One  commenter suggested  that  the Agency allow a  genera-




 tor  to use  any test that is believed  appropriate  for




 determining  reactivity.  Similarly, one commenter




 suggested  that Appendix  III to  this background document




 be removed because it  might discourage  use  of a  suitable




 test .




      This comment must  be evaluated  in light of  the




 Agency's decision not  toprescribe any  tests  for mea-




 suring reactivity.  Ordinarily, when  the  Agency  pre-




 scribes a  specific test  for measuring  a characteristic,




 the  generator is free  to employ a different test  if he




 can  demonstrate, in accordance with the equivalency




 procedurees  set  forth  in Subpart E,  that  his  test  is




equivalent  to the Agency-prescribed test.   Since  the




Agency has  elected not to prescribe any test  protocols




 for measuring reactivity, the question  of equivivalent




test methods is.  largely mooted: test results  are no




 longer determinative of whether a waste is  reactive




and there is nothing against which to measure equivalency.




                      -22-

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 This  is  not  to  say,  however,  that  the  use  of tests  by




 the  generators  is  precluded.   The  generator is  free




 to conduct  any  tests  which  aid him in  assessing whether




 his  waste  fits  within the prose definition of reactivity.




 However, the  Agency  is  not  bound  in any  way by  these




 tests  and will  make  its  assessment of  whether a waste




 is reactive by  reference to  the prose  definition.




      If  a generator  devises  a  test method  which he  be-




 lieves adequately  measures  the reactivity  of a  waste, he




 should submit that test method to  the  Agency for evalua-




 tion.









 One  commenter suggested that  the Agency  address  reacti-




 vity  over time  in  the definition since a material may




 undergo  physical and  chemical  changes  as it  ages  and




 become extremely reactive, whereas  it  might  not  be




 reactive when first generated.




      The Agency agrees with  the comraenter  that  some




 materials,  such as certain ethers,  can become more  re-




 active with time.  However,   the Agency has  no information




 (such as damage incidents) concerning  any  was te s which




might present this type of problem.  Additionally,  the




Agency is not aware of any testing  method  by  which  such




wastes might be identified.   Therefore, the  final regula-




 tion will not address reactivity over  time  per  s e;  as




 these wastes are identified  by  the  Agency  they  will be




 listed in Subpart D of Part  261 of  the regulations.






                      -23-

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        One  commenter  objected  to  the Agency defining as reactive




        those  wastes which  are  capable of detonation or explosive




        reaction  if  subjected  to  a strong initiating source or




        heated under confinement.   The commenter asserted that




        many inert,  non-reactive materials,  including tap water,




        can be triggered  to  detonate  or explode under confinement




        when subjected  to strong,  heat,  pressure,  or a combination




        of these  and other  initiating sources.




            The  Agency disagrees  with this  coTamenter and takes




        specific  issue with  the assertion that  many  relatively




        inert  substances  could be  made to explode  when subjec-




        ted to  extreme heat  and pressure.  In any  event,  even




        if relatively inert  substances could be made to explode




        when subjected to strong heat  and pressure,  these sub-




        stances would not be considered  reactive under the  pro-




        posed  definition.  The Agency  is  only concerned with




        substances capable of exploding  under reasonable  confine-




        ment conditions -- i.e., those  confinement conditions




        likely  to be encountered in disposal environments.




V .    Promulgated Regulations




     As a result of EPA's review  of  the  comnents  regarding




the reactivity characteristic, EPA is  promulgating  a  reactivity




characteristic which significantly differs  from the proposed




regulations  in two aspects:  the  thermal  instability  and shock




instability test protocols  cited  in  the  proposed  regulation




has been removed and the sect ion  relative to generation  of




toxic gas, hydrogen cyanide and hydrogen  sulfide has  been






                             -24-

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 made more  specific.   The  thermal  instability  test  protocol

 was removed  because  the Agency  determined  that  its  interpre-

 tation  was too  subjective  for use  in  a  regulatory  program*.

 (See Appendix  IV) .

 261.23  Characteristic of  reactivity

     (a)   A  solid waste exhibits  the  characteristic  of  reactivity

 if a representative  sample  of the  waste  has any  of  the  following

 properties:

 (1)  It is normally  unstable and  readily undergoes  violent

     change  without  detonating.

 (2)  It reacts  violently with water.

 (3)  It forms potentially explosive mixtures  with water.

 (4)  When mixed with  water, it  generates toxic gases, vapors

     or fumes in a q'uantity sufficient  to  present danger  to

     human health or  the environment.

 (5)  It is a cyanide  or sulfide bearing  waste which, when ex-

     posed to conditions of pH  between  2 and  12.5,  can  gen-e

     erate toxic gases, vapors  or  fumes  in a  quantity suffi-

     cient to present danger to human health  or  the  environ-

     ment .

 (6)  It is capable of detonation or explosive reaction  if sub-

     jected  to  a strong initiating source  or  if  heated  under

     confinement.

 (7)  It is  readily capable of detonation or explosive decompo-

     sition or reaction at standard temperature  and  pressure.
*"Evaluation of Solid Waste Extraction Procedure and Various
Hazard Identification Tests" , (Final Report), NUS Corporation,
September, 1979, (Appendix IV)

                             -25-

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(8)  It is a forbidden explosive as defined in 49 CFR 173.51




     or a Class A explosive as defined in 49 CFR 173.53,  or




     a Class B explosive as defined in 49 CFR 173.88.






     (b)  A solid waste that exhibits the characteristic  of




reactivity, but is not listed as a hazardous waste in Subpart




D, has the EPA Hazardous Waste Number D003.
                             -26-

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                          APPENDIX I




      SELECTED DAMAGE INCIDENTS INVOLVING LAND DISPOSAL




                      OF REACTIVE WASTE











1.   Santa Cruz, California - A bulldozer operator was overcome




by hydrogen sulfide (H2S) fumes generated while mixing tanning




wastes with other wastes.  (Four deaths have occured in




California between 1963-1976 from inhalation of H2S from




waste tanning sludge.




2.   Baltimore County, Maryland - Six nen were hospitalized




due to the inhalation of hydrogen sulfide gas liberated from




salts being landfilled.




3.   Edison Township, New Jersey - A bulldozer operator was




killed at a landfill when a barrel of unknown waste exploded.




4.   Crosby, Texas -Residentsin-the area were subjected to




sore throats,  nauseau, and headaches when toxic fumes were




released from the reaction between oily wastes and acids,




dumped in an abandoned sand pit (twenty-six wells were closed




by this  incident).




5.   Edison Township, New Jersey - Cases of conjunctivetis ,




eye irritation,  burn on cornea, and chemical burns resulted




from reactive wastes being landfilled.




6.   Northern California - A drum of toluene ciisocyanate




(TDI) exploded,  spreading extremely toxic toluene diisocyanate




throughout the area.
                             1-1

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 7.   Los Angeles,  California  -  In  Los Angeles County,  a  tank




 truck emptied several thousand  gallons of  cyanide waste  onto




 refuse at a sanitary landfill.  Another  truck subsequently




 deposited several  thousan'ds gallons of acid waste at  the sane




 location.  Reaction between the acid and the cyanide  evolved




 large amounts of toxic hydrogen cyanide  gas.  A potential




 disaster was averted when a local  chlorine dealer was  quickly




 called to oxidize  the cyanide with chlorine solution.




 8.   California -  Sulfide waste was added  to s.oluble  oil




 waste in a tanker  and subsequently added to other oily wastes




 in a tank.  Later  treatment fo  the oil with acid to break the




 emulsified oil resulted in the  evolution of hydrogen  sulfide.




 Two operators were briefly affected by the gas.  There was




 also an explosion  in the tank.




 9.   Dundalk, Maryland - At a. sanitary landfill near  Dundalk,




Maryland^ a 2,000-gallon liqu.id industrial waste load  containing




 iron sulfide, sodium sulfide, sodium carbonate and sodium




 thiosulfate along with smaller quantities of organic  compounds




was discharged into a depression atop an earth-covered area.




of the fill.   When it reached eight to ten feet below  the




point of discharge, the liquid started to bubble and  fume




blue smoke.   The smoke cloud quickly engulfed the truck  driver




and disabled him.  Several nearby workers rushed to his  aid




and were also felled.   During the clean-up operation,  one of




the county firefighters collapsed.  All six of the injured




were hospitalized and treated for hydrogen sulfide poisoning.
                             1-2

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 It was  not  determined whether  the  generation  of hydrogen




 sulfide was  due  to  the  instability  of  the  waste or  the




 incompatibility  of  the  waste with  some of  the  landfill




 materials.   (The pH of  the waste was 13 when measured before




 it left the  plant).




 10.  Los Angeles,  California - When  the laboratory  drain  at a.




 Los Angeles  hospital was being cleaned by  scraping,  the drain




 pipe exploded scattering fragments  of aetal from  the pipe.




 Two subsequent attempts to remove  the  residual piping with




 screwdriver  and hacksaw resulted in  explosions in both




 instances.   Fortunately, no one was  injured in these explosions.




 The cause was later attributed to  shock, sensitive lead azide




 formed in the lead pipes.   A test  solution, containing sodium




 azide as a preservative, was routinely poured  into  the sewer




 drain line after use.   This chemical accumulated  in  the pipes




 and reacted  with the lead in the pipe  to forn  shack-sensitive,




 explosive crystals of lead azide.




 11.  Riverside County, California -  Several drums of phosphorus




 oxychloride, phosphorus thiochloride and thionyl  chloride




 (all oxidizing agents) were improperly dropped off  at1 a dump.




Later,  during a flood, the drums were unearthed,  ruptured, 




 and washed downstream, releasing highly toxic hydrogen chloride




gas and contaminated the water.




 12.  California - A disposal site in central California




accepted a load of solid dichroaate  salts  (oxidizing agents)




and dumped it into a pit along with  pesticide formulations




and empty  pesticide conainers.   For  several days  thereafter,




                             1-3

-------
 snail  fires  erupted  in  the  pit  due  to  the oxidation of  the




 pesticide  formulations  by the dichromate.  Fortunately,  the




 site personnel were  able to extinguish these fires before




 they burned  out of control.




 13.  Southern California -  A company using toluene diisocyanate




 (TDI)  in the manufacture of plastic and foam rubber automobile




 products collected and  stored its TDI wastes on-site in  55-




 gallon metal drums with clamp type  lids.  After an extended




 period of  time during which thirty  such drums had been




 collected, a hauler  was contacted to transport the wastes to




 a Class I  site in Southern  California.  The hauler stored




 these drums  in an open  area at his  facility for approximately




 two weeks.   Heavy rainfall  occurred during this period.  Upon




 arrival at the disposal site a violent explosion ruptured one




 of the drums.  There were no injuries associated with this




 incident.   During storage some water apparently condensed or




 leaked into  the drums through the clamp-type lids.  Transportation




 of the drums then provided the agitation to accelerate the




 reaction between water  and TDI.  The rapid production of C02




 caused extreme pressure build-up on one of the drums and




 subsequent violent rupture.




 14.   Southern California - In 1972 at a disposal site in




 Southern California,  reaction of sodium chlorate (oxidizing




 agent)  with refuse started a fire which lasted for two hours.




There were no injuries associated with the incident.
                             1-4

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Dirt contaminated with NaC104  (oxidizing agent) was drummed




and tranported as "Nad" to the sanitary landfill.  The drums




were emptied onto re.fuse.  The contents of the drums were wet




but reacted with the refuse to cause a fire upon dumping out.




A similar incident involving NaC104 and refuse producing a




fire occured in 1973.  This incident involved containerized




material that reacted with refuse when a container ruptured




during the covering operation.




15.  Southern California - A' standard procedure at a Southern




California disposal site for handling cyanide-bearing liquid




wastes and spent caustic solutions was to inject these loads




into covered wells dug into a completed section of a sanitary




landfill.  Routine air sampling in the vicinity of the wells




defected low levels of HCN.  No cyanide was detected during




addition of the spent caustic to a new well.   On the basis of




these discoveries,  use of the wells was discontinued.   The




cyanide gas was apparently formed in the well as a result of




lowering of the pH of the waste by carbon dioxide and organic




acids produced in the decomposition of refuse.




16.   A delayed reaction between phosphorus oxychloride (oxidizing




agent)  and water in a 55 gallon drum caused violent rupture




of the  durm and killed a plant; operator.   The steam and




hydrogen chloride gas generated by the reaction caused the




explosion which propelled the bottom head of  the drum




approximately 100 yards from the scene.
                             1-5

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                          APPENDIX  II




       STATE,  FEDERAL  AND  NFPA  REGULATIONS  AND  GUIDELINES









 1 .  Texas
The Texas Water  Quality  Board  uses  the  following  definition:




"Industrial Hazardous Waste" means  any  waste  or mixture  of




waste which ...  generates  sudden  pressure  by  decomposition,




heat or other means  and  would  therefore  be  likely  to  cause




substantial personnel injury..."  -  in combination  with a listing




of 40 compounds.




2.  State of Washington




Defines explosive using  a  5" drop test,  or  class A explosive




(see DOT) definition.




3.  P ennsyIv an i a




Combines Flammables  and  Explosives  and  uses only  the  following




list:




          (1)   Munit ions




          (2)   Blasting  Materials




          (3)   Pressurized Cans




          (4)   Paint Thinners




          (5)   Solvents




          (6)   Kerosene




          (7)   Oils




          (8)   Petrochemical Waste  Sludges




          (9)   Petroleum Waste Sludge




4 .   California




Uses the following definition:




                             II-l

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      "A waste,  or  component  of  waste  is  considered  pressure




 generating  or  reactive  if  it:




      1)   Is a  Forbidden or  class  A,  B,  or  C  explosive  as  de-




          fined  in  Title 49  CFR, Sect ions  173 . 51, 173.88,




          and  173.100 respectively (see  DOT).




      2)   Is a  water reactive material.




      3)   Is in  NFPA category 2, 3, or 4  (see  NFPA)".




 5 .  Illinois




 Uses  the  following  definitions:




      "Explosives" - Any waste having  concentration  of 1 % or




 more  of a substance described as an explosive  (high,  low,  or




 permissible) by  Sax (Dangerous  Properties of Hazardous  Materials




 by N.  Irving Sax, Van Nostrand  Reinhold)  shall be considered




 as explosive "per se".




      "Reactives" - Any waste having a composition of  5% of more




 of a  substance that (as described  by Sax) readily reacts




with  air,  water, or other substances to produce heat  and/or




 toxic  fumes  shall be considered a  reactive waste.   The  definition




 includes oxidizing agents.




6.  NFPA




          Category 0 -  Materials which in themselves  are nor-




                       mally stable, even, under fire  exposure




                       conditions,  and which are not  reactive




                       with wat  er.




          Category 1 -  Materials which themselves are normally




                       unstable  and readily undergo violent




                       chemical  change but do not detonate.




                             II-2

-------
                       Also materials  which may  react  violently




                       with water  or which may  form  potentially




                       explosive mixtures with  water.




          Category 3 - Materials which  in themselves are  capable




                       of detonation or  explosive  reaction  but




                       require  a strong  initiating source or




                       which must  be heated under  confinement




                       before initiation or which  react explo-




                       sively with water.




          Category 4 - Materials which  in themselves are




                       readily  capable  of detonation or of




                       explosive composition or  reaction  at




                       normal temperatures, and pressures.




7 .   DOT




The Department of Transportation lists  explosive wastes (these




are typically propellants, explosives,  initiating  compounds




etc.) and also specifies testing methods for liquids and




solids unstable to thermal and  mechanical stresses.  (See 49




CFR 173.53) .
                             II-3

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                       Appendix  III



     The testing methods examined  in  this section* are

separated  into tests  for thermal instability,  (Tests I thru

X)  tests for  impact mechanical shock  instability  (Tests XI a

and b) tests  identifying oxidizing agents,  (Tests XII thru

XIV) and a  test identifying water  reactive materials (Test

XV).
1.   Most of the information contained in this Appendix was
taken from "A Second Appraisal of Methods for Estimating Self
Reaction Hazards" E.S. Domalski Report No. DOT/MTB/OHMO-76/6.
                            III-l

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A.   Tests Identifying Wastes Unstable to Thermal Stress






    I.    JANAF (Joint Army Navy Air Force) Thermal Stability Test




    Number Six for Liquid Propellants.






    1.    Purpose of Test:




         To determine the maximum temperatures to which thermally




    unstable liquids can be subjected for short periods of time




    without danger of explosive decomposition.




    2.    Operating Principle:




         Under confinement in  a microbomb,  a liquid sample is either




    heated rapidly and held at  a pre-determined temperature for




    an  arbitrary time interval, or heated at a constant rate until




    evidence of rapid decomposition appears.  Spot immersion is




    also  possible,  where th'e microbomb containing the sample is




    immersed into  the bath at  some elevated temperature.




    3.    Test  Description;




         A microbomb which is  drilled and tapped for  a thermocouple




    and burst  disc  fitting,  has an internal volume of 1.3  cm^.   A




    liquid sample  of 0.5 ml  volume is used  and burst  diaphrams




    ranging  from 300 to  8400 psi failure pressure can be  used.   The




    microbomb  is immersed  in a  bath  containing a bismuth-lead alloy,




    which  melts  in  the  range of 65.6C(150F) to 12 1 . 1 .C ( 25 0  F ) .




    Maintenance  of  the  bath  around 93 .3C (200"F) and of  the




  .heating  rate at  -6.7eC  (20F)  per minute, allows  detection




    of the  rate  of  decomposition of  -16.7C  (2" F) to  -1'5'C (5F)




    per minute.  An  air-vibrator is  used to  agitate  the bath and




    the sample  in  order  to  establish  the desired.heat transfer






                                III-2

-------
 between  bath  and  sample.   The  sample  temperature  and  the




 temperature difference  between the  bath  and  sample  are  recorded




 as  a  functions  of  time.   The  temperature at  which self-decompo-




 sition begins  and  the rate  of  decomposition  can be  derived.






 4.    Test Evaluation:
     This  test  utilizes  small  samples  of  material  in  good  thermal




contact with  thermostated  suroundings.  The  temperature  of the




sample can be increased  with time  at such a  slow rate  that




quasi-steady  states  are  maintained.




     Rates of decomposition can be  estimated  from  plots  of the




sample temperature vs. time, and from  plots  of  the  temperature




difference between the sample  and  bath vs. time.   The  slope  of




the temperature differential curve  represents  the  rate of  heat




transfer between the sample and the bath.  Factors  which need




to be taken into account are the rate  at  which  the  bath  is  being




heated, heat ing from the self-reaction of the  sample,  and




temperature gradients in the microbomb.   From  a plot of  the




self-heating rate of the sample vs. the reciprocal  of  the




temperature, a  linear slope proportional  to  the activation




energy should result.  The precision of activation  energies




derived in this manner is about +_  15 percent.






5.   Applicability, of Test as an Index of  Waste Reactivity:




     The activation energy of  the reaction in quest ion, while




certainly an important parameter in assessing waste reactivity
                            III-3

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 (as discussed  previously)  is  not  the only parameter.




 Also  important  are  heat  of  reaction, waste geonetry,




 density; the heat  transfer  etc.   To  indicate a particular




 activation energy  as  a cut-off  for waste reactivity would




 result  in many  false  positives  and negatives.






 II.  ASTM \(_Am_erican So^ie_ty f^or JTe_s_t ing_and_Mater ials)  Standard




     Method of  Test E-476-73^ Thermal I_ns tability_of Con-




     fined Co_nde_nse_d  ^hase  Sys_te_ms_( Confinement T^est)






 1.  Purpos^e of  T_est:




     To determine  the temperature at which a checical mixture will




 commence reaction,  liberating appreciable heat or pressure,




 when subject to a  pro-grammed  temperature rise.  This method




 applies to solids or  liquids  in a closed system in air  or some




 other atmosphere present initially under normal laboratory




 conditions.




 2 .  Ope_rat_ing_Pr i ncip_lej








     The sample to  be tested  is confined in a  closed vessel



 equipped with a burst diaphram, pressure transducer, and




 thermocouple.   The  apparatus  is equilibrated in a bath  at




room temperature and  subsequently heated at a  constant  rate.




The temperature difference  between the  bath and sample,  the




pressure in the closed vessel, and the  bath temperature  are




recorded continuously during  the  course of  the test.
                            III-4

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 3 .    Test  Description;




      This  apparatus  is  a modification of that described under




 the  JANAF  Thermal Stability Test.   The sample (300 rag.) is




 placed  in  the  test  cell  or  vessel  (volume 1 cm')  and is in




 intimate contact  with  a  thermocouple.   The apparatus also has




 a burst diaphram-vent  tube  system  to release gases formed during




 decomposition  if  the  pressure  reaches  too high a  value, and a




 pressure transducer  to  provide measurement of the total pressure




 inside  the  vessel as heat  is  supplied  from a bath at a. constant




 rate.   The  nominal heating  rate of the bath is 8 *C (46.4F)




 to 10C (50"F)  per minute.   Silicone oil is used  in the




 range 0" C  (32*F)  to  370C  (698F)  and  a low-melting alloy




 (i.e., Wood's metal) in  the range  100C (212eF)  to 500C  (932F).




 Recorders  are used to ..monitor,  firs.t,  the difference between




 the  sample  temperature,  (T)  and bath temperature, (Tg)  as a




 function of bath -temperature,  and,  second,  pressure, (P)  as a




 function of bath  temperature.   No  agitation is used so  as to




 minimize thermal  lag.




 4 .   Test Evaluation:




     The threshold temperature  is  the  lowest temperature  at the




 left hand base  of the positive  peak  which appears in the  plot




 of (T)-(TQ) vs  TO .  The  threshold  temperature is  an indication of




 the onset of thermal instability in  the sample.   A potential




hazard exists,  therefore, when  the  temperature of the  sample




 exceeds this value.  The instantaneous  rate of pressure versus




bath temperature, the maximum  pressure  generated  and the  rate




 of pressure rise  are useful hazard  parameters  related  to  rough




 approximations  of reaction  time, and damage potential.




                            111-5

-------
      Examination  of  the  rate  of  temperature  rise  of  the




 sample,  (dT/dt) and  rate  of temperature  rise  of  the  bath  '(dT0/dt)




 not  only  allows an evaluation  of  the  Arrhenius constants,  but




 also  provides  for arbitrary scaling  of  the process.   A simpler,




 and  probably preferable  procedure, may  be  to  record  only  TQ




 corresponding  to  a runaway condition  (e.g..  a. specified value




 dT/dt dTo/dt,  or  rupture  of a  pressure  disk  (there  is some




 arbitrariness  in  the  definition  of the  runaway criterion,  but




 this  feature may  not  be  serious)), and  then  repeat  the experiment




 with  a different  sample  diameter, d.  The  Frank-Kamenetskii




 condition then gives  the  value of E  from




          (dl/d2)2 =  (Toi/To2)2  exP  (E/R)  (1/Tol~1To2U-



 This  procedure obviates  the necessity of evaluating  A and IN , and




 allows immediate  seal-ing  to any  size.




 5.    App_licab_il_ijty of_Tej_t_ a_s_  an _Ind_ex_of_Waste_ Reactivity:




      This test suffers from the  same  drawbacks as the JANAF




 test, i.e., the activation energy obtained from the  test




 is not a definitive  indicator  of waste  reactivity.




 III.  SELF HEATIN ApIABATI_C_T_EST__




      This test is run under adiabatic conditions.   Conditions  of




 this  sort do not correspond to normal waste management conditions,




 and thus the test results are  not likely to be reflective  of actual




waste reactivity.   Since  different information cannot be  obtained




from  this test than  is already available from tests  I and  II,  a_n_d




the test conditions correspond less to waste  management conditions




than do tests I and II, no further evaluation of  this test is




presented here.






                            III-6

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IV.  THERMAL SURGE TEST




1.   Purpjpse of Test1.




     To determine explosion  temperature  (temperatures  for




which there is a delay time  of 250 sec before  explosion).




2.   Operating Principle:




     The discharge of a  capacitor across a  thin-walled  tube




provides the thernal stimulus to initiate explosive decomposition.




The time-temperature profile of the decomposition  is obtained




from oscillographic records.  Although the  tubes are thin-walled




(0.089 mm), they have considerable strength and provide  a  state




of heavy confinement for the explosive or unstable material.




3.   Test_Description:




     A test sample is loaded into hypodermic needle tubing which




is heated, essentiall-y instantaneously,  by  a capacitor  discharge.




The temperature and time of  the explosive event are recorded




from a continuous measurement of the electrical resistance of




the tubing by means of an oscilloscope.  The test  is particularly




suited to liquid material but solids can also  be accomodated




by melting prior to their insertion into the hypodermic  needle




tubing.   Materials are subject to temperatures in  the range of




260C (500F) to 1100C .(2012F) and delay  times of 50  in




sec. to 50  sec.   The delay  time, T is given by A  exp (B/RT)




where A and B are constants  (somewhat related  to the Arrhenius




pre-exponential factor and activation energy), R is the  gas




constant,  and T is the absolute temperature.




4.   J_es_t Ev au 1 j_t_i on :




     The thermal surge test  supplies data on explosion






                             III-7

-------
 temperatures which  represent  conditions  of minimal heat  transfer.




 This test measures  the true induction  tine of an explosive  rather




 than the time  required to heat up  the  sample.  Wenograd  15




 was able to show a  correspondence  between the temperature of the




 system 250 sec prior  to explosion  and  impact test data.  The




 activation energy parameter obtained in  thermal surge test




 measurements under  dynamic conditions  are considerably lower




 than those determined in other measurements under isothermal




 conditions.  This test is probably one of the best available




 approximations to a point source heat  initiation of an unstable




 material in a multicomponent  system.




 5.   Applicability  of Test aj_ an Index of	Was_te	Reactivity




     The high temperatures the test materials are subjected




 to in this test do  not correspond  to the temperatures which




wastes might be subject to during  management (unless the




waste is subject to a strong electric  discharge).  For this




 reason, this test is unacceptable.






V .   ADJ. A_B AT! 1C STORAGE TEST




     Like test III, this test is run also under adiabatic




conditions, and therefore no further evaluation is presented.




VI.  ISOTHERMAL STRONG TEST




     This test determines the heat generation rate as a  function




of time and estimates the induction period at a given temperature




for a material.  This test is run  under  isothermal conditions




and takes anywhere  from weeks to months  to complete.   For these




reasons,  no further evaluation is  presented.




                            III-8

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VII.  EXPLOSION TEMPERATURE TEST




1.    Purpose  of T_est




      To  determine  the  temperature  at  which  a  material  explodes,




ignites, or decomposes after a five second  immersion in a Wood's




metal bath.




2.  Operating_Principle




     This  test gives an  estimate of how close  the  explosion




temperature is to  ambient condition for a material, and, hence




provides a measurable  indication of thermal instability.




3.   Tet Description:   




     The material  to be  tested (25 mg.) is  placed  in a copper




test tube (high thermal  conductivity)  and immersed in  a Wood's




metal bath.   This  test is made at  a. series  of  bath temperatures,




and the time  lag prior to explosion at each temperature is recorded.




The bath temperature is  lowered until  a temperature is reached a-c--"




which explosion, ignition, or apparent decomposition does not occur.




The bath temperature working range is  from  about 125C (257F)




to 400C (752F).   The sample is removed from  the  bath after




5 minutes if  no explosion has occurred at 3608C (680F).




4.   Test Eva_luji_t^on:




     The explosion time  is very nearly independent of  sample




size provided, the sample size is in the range  10 to 40 mg.




Particle size is also important in providing consistent re-




sults  for a group of materials.   Rapid equilibration of the




sample upon contact with the high  tenperature  bath will depend




upon the heat capacity and thermal conductivity of the material,
                            III-9

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 and  could  be  a  major  uncertainty in the test.   Explosion tempera-




 ture  data  is  a' function  of  time  and serves  as  useful indicators




 to assist  in  maintaining safe  thermal  conditions  during handling




.and  transport.




 5.    Applicability  of  Test  as  an Index  of Waste Reaetivity:




      This  test  would  seem the  most  suitable  for our purposes.




 The  test results  are  pass-fail,  either  an explosion, ignition,




 decomposition etc.  takes place or not.




      Problems  do  arise out  of  distortion of  thermal transport




 from  sample size.   However,  this is a  problem  with  all  tests.




 Also  the Woods  Metal  Bath  results in Cadmium fumes  being generated




 and  should only be  operated  in a hood.  A sand  bath or  nonflammable




 oil bath might  be more suitable  for our purposes.




      Field testing  of  this  method indicate  that it  is unsuitable




 for use without other modifications (see Appendix IV).




VIII. EXOTHERMIC DECOMPOSITION METER TEST




 1.    Purpose  of Test;




      To determine the self-heating  of  a sample  at small to




moderate heat generation  rates as a function of temperature




or t ime.




2 .    Operating Principle:




      A cylindrical  aluminum block contains  a cavity which  has




a Peltier element attached  at the bottom and a  sample is  placed




on the Peltier element.  Heat flow  from the  block to the  sample




is measured by means of  the Pe1tier e1ement  which provides
                            111-10

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an'electrical  signal  to  a  recording  device.


3.   Test Description:


     A sample  vessel  constructed  of  stainless  steel  (volume,


2 cm^) is positioned  over  a Peltier  element, and  both  are


housed inside  the  cavity of a  cylindrical  aluminum block.


This central block is surrounded  by  mantles containing  elec-


trical heating  elements  in addition  to  an  insulating  layer.

The electrical  input  to  the block and mantles  is  maintained


in  such a manner as to keep the temperature difference  between


the block and  mantles as small as possible while  the  block is


heated linearly at about 108C  (50F) per hour.  The heat flow


from the aluminum block  to the sample is measured by  the


Peltier element.  As  soon  as the  sample begins  self-reaction


the heat flux  to the  sample starts to decrease.   From  a plot
                                                                  r*
of  the heat generation of  the  sample vs. the reciprocal of


the absolute temperature,  the  activation energy can be  calculated.


4.   Test EvaJUiatij3n_:_


     Changes in the heat capacity of the aluminum block over the


temperature range 20C (68F)  to 200C  (392F) will cause the


temperature increase over  this range to be slightly non-linear.

The Peltier element is temperature dependent, and calibration


using a pure copper sample having known thermal properties is


recommended.


5 .   Ap p Li_c_ab_il_ity of T_es t_as an _Index_o_f_Waste Re a c t i v i t y


     This test yields activation energy and is, as a  result,


subject therefore to the same  drawbacks as tests  I and  II.




                            III-ll

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 IX    Homogeneous Explo_sion_Test




 1.    Purpose of Tes_t:




      To  determine  the pressure-time profile of the  thermal




 explosion  of solid or liquid materials.




 2.    Operating Principle:




      A sample is heated under adiabatic conditions  in a closed




 vessel until explosion occurs.  The maximum rate of pressure rise




 and the  maximum overpressure are measured as a function of




 time  at  different heat input rates.




 3.    Test__Description_:_




      About 100 ml of a sample is introduced into the lower part




 of a  stainless steel vessel. The lower section is sealed off




 from  a larger upper section above by a membrane (breaking




 pressure 1 bar).   The larger upper section serves as a free




 space for  the expansion of reactant or product vapors.




 During the main part of the induction period,  pressure equali-




 zation is  accomplished by a capillary tube connecting the




 upper and  lower sections of the vessel.   The two-compartment




 vessel is  placed inside a larger vessel of 20 liter capacity




 which seals the former from the external surroundings.  A




 heating mantle around the latter vessel allows heating of the




 inner vessel to take place as near to adiabatic conditions




 as possible.   Around the sample vessel there is also an




auxiliary heater  which heats the sample at a constant (but




adiabatic)  rate until explosion occurs.   When explosion




takes  place,  the  membrane is ruptured and expansion into the




larger volume takes place.  A piezo-electric pressure transducer






                            111-12

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 records  the  pressure  prior  to,  during,  and  after  explosion.




 4.   Test  Evaluation:




     Differentiation  of materials which give  large rates of




 pressure rise and  overpressures  can be  singled  out from those




 which give low values.  Subsequent precautions  for management




 can be taken.




 5.   Applicability of Test  as an Index  of Waste Reactivity;




     This  test identifies those  wastes  which  react under




 thermal  stress to  produce la.rge  pressure gradients.  This




 information  could  be  of use to  identify potentially reactive




 wastes, hazardous  due to pressure generation.   This type of




 reactive waste would  also be identified by  the  explosion




 temperature  test since some part of degradation or change  in




 the sample would be apparent for the samples  failing this  test.




 X.   Differential Thermal Analysis (DTA) Test




 1.   P_urj>jos_e_ of Test:




     To determine  exothermic and eadothermic  reactions in  a




 material as  heat is applied at a particular input rate.




 2.   Operating-Principle;                   l




     The material under test and a stable reference material




 are heated simultaneously at the same rate.   Exothermic and




 endothermic  traces are measured  using a recorder  providing a




 temperature-time plot of the reaction process.




 3.   Test Description:




     The material to be tested (5 to 25 mg) and a. reference




material (such as alumina or glass beads) are placed into




 identical compartments in an aluminum block.  Heat is supplied






                            111-13

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 to both  compartments  at  the  same  constant rate  of  input.




 Temperatures are measured using therno-cocples  in  conjunction




 with automatic  recording devices  so  that a plot  of  temperature




 vs. time is obtained.  A shift in  the  base line  results  from a




 change in  the heat capacity  or mass  of  the naterial under test.




 Particular care must  be given to  the type of  temperature sensor




 used and to the choice of its location, in the conpartment inside




 the aluminum block.   The geometry  of the sanple  and thermal




 characteristics (such as thermal  conductivity)  of  the  sample




 will affect the shape of the DTA  curve.




 4.   Test_Ev_a_luation_:_




     From  the exotherms and  endotherzs  of the DTA  curve,




 decomposition temperatures corresponding to various rates of




 temperature rise can ~be obtained.  Kinetic parameters  can be




 calculated as a result of properly varying the heating rates




 and assuming a constant degree of  conversion  of  reactant when




 a specific thermal event (such as  the peak temperature of a




 given exotherra) takes place.  When the  temperature sensors are




 placed in the path of the heat flow the DTA apparatus  can




measure the enthalpies of processes such as heats of deconposition



 or transition.          .




5.   Applicability of Test as an Index  of Waste Reactivity:




     This test  will give information as to how a waste reacts,




 thermally,  to thermal stress.  There are several problems beyond




 those  normally  associated with test's of this kind:




     (1)   The stress   is specialized, as is the reactivity




     inf orinat ion.







                            111-14

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          (2)  The test must be interpreted, and is sometimes




          ambiguous (as in the case where several reactions are




          taking place, one of which is eadothermic e.g. decomposition




          of NH4N03).




          (3)  Usually very small samples are used, which makes




          getting a representative sample even more difficult.




     On the other handj this is a .standardized procedure which is




     familiar to industry, widely known and often used.




B.   Tests for Reactive Wastes Sensitive to Mechanical S_tr_e_ss




          A great many sensitivity tests using mechanical stimuli




     have been devised, mostly by the military, hence generally




     intended for the  rating of sensitive energetic materials




     (explosives and propellants).  Since we are interested mostly




     in waste commercial materials or b--?roducts of lower sensitivity




     (although handled in larger amounts), the raain problem is to




     select a few suitable tests from the large number of existing




     ones.




     XI .   Impa_c_t_Te_s_t



     1.   Purpose of .Te_s_t ^




          To determine the minimum drop height of a falling weight




     which strikes an  explosive material and produces either a mild



     or violent decomposition reaction.  Both falling weight and




     explosive material have a fixed and constant mass.




     2.   Operating Principle:




          Impact energy is supplied to an explosive by a weight, of




     constant mass which is dropped fron varying heights to establish




     the  minimum height to providedetonation, decomposition, or





                                 111-15

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charring.  The impact provides rapid  compression and crushing




of the sample (which may involve a frictional component  of




crystals rubbing against crystals) and detonation ensues.




3.   T_est De_sc^rj.jrtion :




     The two most prevalent impact tests are those by  Picatinny




Arsenal (PA) (Test XI a) and the Bureau of Mines (3M)(Test XI  b).




     In the PA apparatus a sample is  placed in the recess of a




small steel die cup, and capped with  a thin brass cover.  A




cylindrical steel plug is placed in the center of the  cover,




which contains a slotted-vent and the impact of the 2  kiram




weight is transferred to the steel plug.




     In the BM apparatus a. 20 rag. weight is always employed while




the PA sample size may be varied for  each experiment.  The explosive




sample is held betwee'n two flat parallel plates made of  hardened




steel and impact is transmitted to the sample by means of the




upper plate.   Sample decomposition is detectable by audible,




visual or other sensory means.




     In an apparatus used by the Bureau of Explosives  (part




of the Association of American Railroads) and cited in Title




49 CFR (DOT Hazardous Materials Regulations) a falling weight



is guided by a pair of rigid uprights into a haamer-anvil




assembly containing a 10 mg. sample of explosive.  Reproduci-




bility can become a problem here because of a non-ideal




collision between the drop weight and the impact hantaer  since




only  a fraction of the drop-weight energy is transmitted to




the sample.
                            111-16

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     4.   Test Evaluation:

          Greater confinement of the sasple will limit the translational

     component of the impulse to a smaller area as is the case with

     the PA apparatus.  Factors which play an influential role in

     the test are:  materials of construction, sample thickness, sample

     density, hammer geometry, mass of drop weight, impact area,

     surface finish, the surrounding atnosphere, temperature, and

     pressure.  Modifications can also be made to accomodate cast

     and liquid samples.

     5.   Applicability	of These Tests^as^Indicies of Waste Reactivity;

          Impact tests suffer from the drawback that the fundamental

     processes leading to energy release are complicated and poorly

     understood.  Failure of good agreement between various impact

     tests shows that these tests contain uncontrolled parameters.

     On the other hand,  (1) partial correlations do exist, (2) the

     history of the test indicates rough agreement with field

     experience, (3) the stimulus is of reasonable severity,  (4) the

     tests are widely known and realtivelj easy to use.  These facts

     make them useful for a partial definition of hazards.

C.    Tests Identifying Oxidizing Wastes^

     XII . Burning Rate Test for Solid Oxidizers^

     1. .   j? ur_p_oj_e of Tes tj_

          To determine the relative fire hazard present when in-

     organic oxidizers are heated in the presence of wood or  cellulosic

     subs tances.

     2 Most~o~fthe information contained in this section was  taken
       from "Classification Test Methods for Oxidiz.ing Materials"
       by J. M. Kutcha,  A. I,.  Furno,  and A. C. Imhof,  Bureau  of
       Mines,  Report of  Investigations 7594.

                                 111-17

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 2.   Operating  Principle:




     A  set  sample  size and  ratio  of dried  sawdust  (12-50 nesh)




 and oxidizer  is  ignited and  the burning  rate  is  determined by




 measuring the time  for the  burning to  propogate  at least 5 inchest






 3.   Test Description




     For the  test,  sawdust  is initially  screened to provide




 particles ranging  in size from 12 to 50  mesh  (Tyler screen




 series).  The sawdust is dried in an oven  at  101.5C  (215F)




 + -15C (5F) for  about six hours, and then test mixtures




 having various  concentrations of  the oxidizers are prepared.




 To obtain a uniform mixture, the materials are agitated for




 10 minutes  or more  in a closed container.  Generally,  fine




 oxidizers are used  "as received" but coarse oxidizers can be




 pulverized  and  screened to obtain sanples  at  least as fine




 as the wood sawdust.  For most of the oxidizers, a particle




 size range  of about 20 to 100 mesh appears to be adequate




 for determining their hazard classification by this proposed




 test.   However, where the hazard level of  such materials is




uncertain because of particle size considerations,  the burning




rates  of the mixtures should also be determined using oxidizer




samples that have fractions finer than 100 mesh.




     Burning rates are measured using a  rectangular rack that




was mounted horizontally and equipped with a  60-nesh  steel screen




to support  the sample.   The sample bed is  separated fron the side




rack nounts  to insure unrestricted .burning along the  sides of the
                            111-18

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 sample.   To  form the sample bed,  the sawdust-oxidizer mixture




 is  placed on a  rack  between a pair of spacer bars vhich fixed the




 bed  size  and which  are  removed before ignition.  The bed can also




 be  formed in a  U-shaped wire screen channel which is transferred




 onto  the  burning rack;  the  wire screen channel is then removed




 before ignition.  The  sample is ignited by a. propane torch or




 similar flame source and the burning rate determined by




 measurements  made with  two  fuse wire (0.5 anp) stations




 and  an electric  timer,  although slow-burning nixtures can be




 followed  visually and  timed with  a stoowatch.   The sample bed




 was  normally  7  inches  long  and the rates are measured over a




 distance  of  5 inches and at least  1 inch from the ooint of




 ignition.




 4.    Test  Evaluation:
     This proposed  test method  permits  classification of solid




oxidizers into  two  or more  groups  based on their relative




burning rates with  a cellulose-type  cotnbustible such  as  wood




sawdust.  The least hazardous class  includes  those  oxidizers that




burn at low rates 10 in/min)  when  aixed  with  the  select-grade,




red oak sawdust.  A second  class consists  of  oxidizers,  such as




the alkali nitrates and chlorates, which burn at relatively high




rates (>10 in/min) when mixed with this sawdust. A third,  more




hazardous class should include  those  oxidizers, which when  un-




mixed or mixed  with a combustible, might ignite spontaneously




and burn vigorously if moisture  is present or if they are heated
                            111-19

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slightly.  This class would include sodium peroxide and calcium




hypochlorite (69.5 percentage C12) which gives very high burning




rates with the sawdust.  A fourth class is also required for those




oxidizers, such as ammonium perchlorate, which may detonate




when heated under confinement or when exposed to shock.




5.   Applicability of Test a_s_ a_n Index of Waste Oxidizing




     Strength




     This method is designed to provide a relative measure of




the increased ignition or burning hazard that may exist when




inorganic oxidizers are mixed with an organic substance such




as sawdust.  They are not applicable to organic peroxides or




to inorganic oxidizers that may detonate when heated with or




without a combustible.




     In the application of this test method, it must be recog-




nized that a reliable hazard rating may not be possible for




all oxidizers using a single reference combustible.  If the




adjacent material is not cellulosic in nature, (and in a




landfill this may or maynot be the case) it is conceivable




that an oxidizer may display a greater level of hazard than




observed with the select-grade, red oak sawdust used in the




present study.




XIII. Ignition Hazard Test for Liquid Oxidizers:






1.    Purpose of Test:




     To determine the relative fire hazard by exothermic reaction




of liquid inorganic oxidizers  with other substances or by




decomposition to products which ignite or sustain a fire.








                            111-20

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Generally,  these  liquids react with nany organic substances and




some are capable  of producing spontaneous ignition when nixed




with the combustible at normal or slightly elevated temperatures;




some may also ignite spontaneously when heated in the absence




of a combustible  material.




2.   Operating Principle;




     In this proposed test, the ignitability or reactivity of




the oxidizer sawdust mixtures is determined in an open reaction




vessel using small quantities of the reactants.  Temperatures




up to at least 87.8C (190F) are used to compare the oxidizers,




depending upon their reactivity.  Such temperatures are not




necessarily unrealistic, considering particularly the possibility




of over-heating from the reaction of liquid oxidizers with




contaminants.  The reaction vessel in these experiments is a




200-cm^' Pyrex beaker that is equipped with insulated heating




tapes and which rested on a flat ceramic heater;  however, a stain-




less steel beaker can also be used.   Because of possible violent




reactions,  the reaction vessel is placed in a larger vessel of




heavy-duty steel  and the experiments are to be performed in a




prot ected area.




3 .   Test Description;




     In a trial,  a predetermined quantity of the sawdust (12 to




50 mesh)  is added to the reaction vessel and brought to the




desired temperature.  The liquid oxidizer is then cautiously




injected  with a  long hypodermic syringe ( 12 inches) fron behind




a  protective shield, and the extent  of reaction is determined




from continuous  temperature measurements and visual observations.






                            111-21

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 The  mixture  temperature  is  measured with a 30-gage iron-




 constantan  thermocouple  protected  against corrosion by a thin-




 walled  glass  sheath  and  located  near the center of the reacting




 mass.   Ignitions  are  confirmed visually  since  the  flame reactions




 does not  necessarily  occur  in  the  immediate  area of the




 thermocouple;  in  many  ignitions, the sawdust-oxidizer  mixture




 is scattered  or the  flames  occurred primarily  near the top  or




 outside of the test vessel.  Generally,  evidence of ignition




 is observed  for periods  of  at  least 15 minutes.   If no significant




 temperature  increase  occurred, experiments  are  made at higher




 temperatures  and  with  various  sawdust-oxidizer  quantities.




 Preliminary  trials are always made  with  a small  quantity of




 oxidizer  1  ml), particularly in  the  case  of  an oxidizer of




 unknown reactivity.




 4.   Test Evaluation:




     This method  is not  applicable  to  detonable  liquid oxidizers,




 such as concentrated hydrogen'peroxide (90  percent)  or perchloric




 acid (72  percent).  A  shock sensitivity  or  thermal  stability test




 (Test XIV) is required for  evaluating  these  types.




 5.   Applicability of Test  as an Index of Waste  Oxldizing Strength




     (see Test XII, No.  5).




XIV.  Self-Heating Test for Organic  Peroxides*




 1.   Purpose  of Test;




     To determine the minimum ambient  temperatures  for  self-




heating to explosion of  thermally unstable compounds in  charges




of specified  shape but varying size.
                            111-22

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2.   Operating Principle:




     The thermal decomposition of organic peroxides is observed




from studying temperature-tine plots to obtain the critical




temperatures for explosion, heat transfer coefficient data, and




apparent activation energies.




     A circulating fan located within the working space of the




furnace provides temperature control to within 0.5C.




3.   Test Description:




     A cylindrical tube furnace is constructed of steel housed and




an aluminum open-topped cylindrical container which could hold 40




to 60 grams of organic peroxide.  The furnace was heated elec-




trically over the range of 50C (122F) to 350C (662F) and




could be maintained at a fixed temperature to within 0.3C.




The progress of selfheating in the peroxide sample relative




to the furnace was observed by using a differential thermocouple




at the center of the sample.  A second thermocouple attached




to the side of the container monitored the surface temperature.




Temperature-time plots were recorded for different cylindrical




diameters for the samples and critical temperatures were




calculated.




     Explosion studies were carried out with sample amounts




as large as 800 grams using a somewhat modified apparatus,




and similar parameters examined.




4 .   Test Evaluation:




     The chief disadvantage of the method is the long period




over which readings must be recorded and the long time required




for the furnace to stabilize following a large change in




operating temperature.




                            111-23

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     5.   Applicability_of_T_est as an Index of Waste Oxidizing

          Strength:

          This test can be used to identify detonable oxidizers, but

     does not give any additional information other than that provided

     by the explosion temperature test.

D.    Tests for Identifying Water Reactivity3

     XV.  Test Method for Water Reactivity3

     1.   u..rJL ^ of Test:

          To identify materials which react so violently with

     water and provide a danger from ignition of nearby combustables,

     generation of flammable gases or generation of toxic fumes.

     2.   Operating Principle:

          Water reactivity of a substance is determined either

     by adding a given weight of water, to a given weight of material

     or vice versa.  In either  case,  the rate of temperature rise

     and the gross temperature  rise are recorded, and the gases

     evolved are sampled for analysis.

     3.    Test Description:

          The sample container  is a Pyrex tube,  1-3/8 inches in

     diameter by 10 inches  long, imbedded to a depth of 3-1/2

     inches in a block of insulating  foam (polyurethane or poly-

     styrene) 3 inches square by 5 inches high.  A thin piece of

     copper 3/8 inch square  and weighing 0.5 gram (about 0.025

     inch  thick)  is silver-soldered to the tip of a chromel-

     al.umel thermocouple which  measures the temperature rise.  This
       Test  XV  is  taken from "Classification of Hazards of Materials--
       Wat er-React ive  Materials  and Organic Peroxides", C. Mason and
       J.  C.  Cooper, NTIS  Number PB-209  422.

                                 111-24

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thermocouple  is placed in the Pyrex tube in such a way that the




copper square is near enough to the bottom to be covered by




the sample.   The output of the thermocouple is fed to a




suitable recorder.




     An initial estimate of the severity of the reaction is




made by adding 5 grams of water slowly to 0.5 gram of material




with, the apparatus behind a protective shield.  Since either




toxic or flammable gases may be evolved, the test must be




carried put in a suitable fume hood.  The temperature rise




is measured by adding 10 grams of water slowly (10-20 sec) from




behind a protective shield to 1, 2, 5, 10, and 20 grams,




successively, of the sample.   Measurements are continued




until the temperature reaches a peak and then begins to drop.




If 1,  2, and 5 grams of the material give virtually no temper-




ature increase in 4 minutes,  10 grams of water are added to




10 grams of sample and the temperature is monitored for 1




hour to determine whether a slow reaction occurs.  If the




reaction is not too violent,  10 grams of water are added




to 20 grams of the material to see whether a greater rise in




temperature results.  The procedure may be reversed by adding




the material to the water in the container.  The best method




to determine whether a flammable or toxic gas is evolved is




by chemical analysis of the gas.  If a gas is evolved, a




sample from the reacting material is collected through a.




flexible needle inserted into .the reaction container to with-




in about an inch of the reacting mixture.  The.sample is then




analyzed on a. chromatograph for flammable and/or toxic gas.




                            111-25

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 4.    Test




      The test  is  reproducible  to within  10 percent.   The  test




 results for  known  reactives  like the hydules  of  the alkali




 metals are positive.   There  seems  to be  little difference in




 the results  caused by  the order of mixing.




 5.    Applicability of  Test as  an Index of Waste  Reactivity:




      A test  such as this could be used to identify pyrophoric




 wastes, wastes which generate  toxic gases when contacted  with water




 etc.




      The test method appears to define the activity of  the




 various materials  tested.  Classification of  the water  reactivity




 hazard could be based  on the temperature rise which is  a




 measure of the heat released by reaction with water.  The




 release of flammable and/or  toxic gases would create  an




 additional hazard which could be covered by a classification




 such  as the  following:




                           t ive Wastes:
          Wastes which react with water to give




          temperature rises of 60C (140F) a_nd_




          evolve toxic or flammable gases.




          Wastes which react with water to give




          temperature rises greater than 60C (140F)




          or evolve toxic or flammable gases.






     Simplified methods of analysis for toxic gas, (particu-




larly HCN and H2S) must be developed before this test could




be considered.







                            111-26

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                         APPENDIX IV
     The information contained in this Appendix was extracted




from "Evaluation of Solid Waste Extraction Procedures and



Various Hazard Identification Tests (Final Report)", NUS




Corporation, September 1979.

-------
  1.    Reactivityt Explosion Temperature Test Testing Method






       The Explosion Temperature Test, which is described in




  Attachment A to this Appendix, was used by two independent.




  laboratories (Safety Consulting Engineers, Inc. of Rosemont,




  Illinois and United States Testing Cotapany, lac.) to determine




  reactivity.  The purpose of this test is to determine the




  temperature at which a material explodes, ignites, or deconposes




  in a  Wood's metal bath after being immersed for five minutes.




 Table IV-I gives the testing results obtained from the Explosion




 Temperature Test.
 2.    Conclusions and Recommendations of the Explosion




      Temperature test




      The proposed Explosion Temperature Test is unacceptable




 on  the basis of the testing results.  Interpretation of the




 testing results is too subjective.




      As a replacement for the Explosion Temperature test, it




 is  recommended that differential temperature methods be




 considered.   For example, differential .scanning calorimeter




 testing (i.e., differential temperature analysis)  is a quick




 and accurate means for objectively  determining  the temperature




 at  which a material will  decompose  or react with other materials




'This  system  is composed of  a  sensitive array of temperature




 sensors,  an  adiabatic chamber,  several small heating elements,




 and  a  data processing and recording system.




     To determine  the amount  of  energy absorbed or given up




 by  a substance,  a  0.1 to  5.0  mg  sample is  placed into the




                              IV-2

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                          TABLE  IV-I

              EXPLOSION TEMPERATURE TEST RESULTS
Sample

Ferromanganese Dust



Ammonium Nitrate
Laboratory

    K

    L

    K
    Testing Results

5 min.  at 350C,  no  reaction

207C,  slignt reaction

Between 300C and 325eC,
major reaction (sample de-
composed,  smoke visible)

 210C, major reaction
                                IV-3

-------
 adiabatic chamber and the temperature Is increased via the




 heating elements.  The data are recorded on a strip chart.




      This is a very sensitive method.  It can detect changes




 such as loss of water of  hydraticn,  phase changes,  etc.




 It will give indications  of innocuous events as  well as  severe




 ones.   Endo- or exothermic  reactions are clearly indicated




 by changes  in the recorded  temperature curves.






 3.    Supplemental General Comments  (These comaents  are those




      provided by  the  two  laboratories participating in the



      testing program)








 1)   Wood's  metal  is  composed  of bismuth (50.09%),  lead  (25%),




     tin  (12.5%),  and  cadmium  (12.5%).   The  use  of  a  molten




     metal bath could  re'sult  in potential OSHA violations




     because  of the toxic nature of  the  metal fumes.




 2)   The  proposed  method  is archaic  and  the  results  are  highly




     subjective rather than objective.   The  nethod  is  time




     consuming.  A thermal  analysis  (i.e., differential  tem-




     perature analysis) is  rapidly performed and the  thermal




     properties are easily  identified.   Testing  results  are




     reproducible and many  commercial laboratories  provide




     these analytical services at reasonable fees.



3)   Determining if a reaction has taken  place by visual




     observations is very subjective.  One laboratory  sealed



     the copper tubes with vise-grip pliers and immersed the




     tubes in the bath.  A reaction was judged to have taken






                             IV-4

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place If bubbles were observed in the molten bath.  The




test procedure gives no standard nethod for sealing the




tubes to prevent molten metal for contacting the sample,




and determining if a reaction has taken place is the




opinion of the analyst.
                        IV-5

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                          Attachment A
                   EXPLOSION TEMPERATURE TEST
                     (March 17, 1978 Draft)
 1.   Purpose of Test

      To determine the temperature at which material explodes,

      ignites, or decomposes after a five minute immersion in

      a Wood's metal bath.

 2.   Operating Principle

      This test gives an estimate of how close the explosion

      temperature is to ambient conditions for a material, and

      hence,  provides a measurable indication of theraal insta-

      bility.

 3.   Test Description

      The  material to be tested (25  mg.)  is placed ia  a  copper

      test tube (high thermal  conductivity) and  immersed in a

      Woodf's metal bath.   This test  is made at a series  of bath

      temperatures ,  and the  tine  lag  prior to explosion  at each

      temperature is  recorded.  The  bath  temperature is  lowered

      until a.  temperature  is reached  at  which explosion,  ignition,

      or apparent decomposition does  not  occur.   The bath temp-

      erature  working  range  is  from  about  125 to  400'C.   Tbe

      sample is removed  from the  bath after 5 ninutes  if  no

      explosion has occured  at  360C.


Taken from "A  Second  Appraisal of Methods  for Estimating Self
Reaction Hazards," E.S. Domalski, Report  No.  DOT/MTB/OHMO-76/6.
Department of Transportation.

                              IV-6

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