EPA-54'1/1-86-003
vvEPA
                      Environmental Protection
                      Agency
—~a of Emergency and
Remedial Response
Washington DC 20460
                      Superfund
Office of Research and Development
Office of Health and Environmental
Assessment
Environmental Criteria and
Assessment Office
Cincinnati OH 45268
                       HEALTH  EFFECTS ASSESSMENT

                       FOR  METHYL ETHYL KETONE

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                                           EPA/540/1-86-003
                                           September  1984
       HEALTH EFFECTS ASSESSMENT
        FOR  METHYL  ETHYL  KETONE
    U.S. Environmental  Protection Agency
     Office of Research and  Development
Office of Health and Environmental Assessment
Environmental Criteria  and Assessment Office
            Cincinnati,  OH  45268
    U.S. Environmental  Protection Agency
  Office of Emergency and Remedial Response
Office of Solid Waste and  Emergency Response
            Washington, DC  20460

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                                  DISCLAIMER

    This  report  has  been  funded  wholly  or  In  part by  the  United  States
Environmental  Protection  Agency under  Contract  No.  68-03-3112  to  Syracuse
Research Corporation.  It has  been  subject  to  the Agency's peer and adminis-
trative review, and  It has  been  approved  for  publication as an EPA document.
Mention of  trade  names or  commercial  products  does  not  constitute  endorse-
ment or recommendation for use.
                                      11

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                                    PREFACE
    This report  summarizes  and evaluates Information relevant  to  a prelimi-
nary  Interim  assessment  of adverse  health  effects  associated with  methyl
ethyl ketone.   All  estimates of acceptable  Intakes  and  carcinogenic  potency
presented In  this  document  should  be  considered as preliminary and  reflect
limited  resources   allocated  to  this  project.    Pertinent  toxlcologlc  and
environmental  data  were located  through  on-Hne literature searches  of  the
Chemical  Abstracts,  TOXLINE,   CANCERLINE   and   the  CHEMFATE/OATALOG  data
bases.  The basic literature searched  supporting this  document  1s  current up
to September, 1984.   Secondary sources of Information have  also been  relied
upon  1n the  preparation of  this  report  and  represent large-scale  health
assessment efforts  that entail  extensive peer and Agency review.

    The intent  1n these  assessments  1s  to  suggest acceptable exposure  levels
whenever sufficient data were  available.   Values were not derived  or  larger
uncertainty factors  were  employed  when  the variable data  were  limited  in
scope tending to generate  conservative (I.e., protective)  estimates.   Never-
theless, the  interim  values presented  reflect the  relative  degree  of  hazard
associated with exposure or risk to the chemical(s) addressed.

    Whenever possible, two  categories  of  values  have  been  estimated for sys-
temic toxicants (toxicants  for which cancer  is  not the endpoint of concern).
The  first,  the AIS  or  acceptable  Intake  subchronlc, Is  an estimate  of  an
exposure  level  that  would  not  be  expected to  cause  adverse effects  when
exposure occurs  during  a limited  time Interval   (I.e.,  for  an  interval  that
does  not  constitute a  significant  portion  of  the lifespan).   This type  of
exposure estimate  has not  been  extensively  used or rigorously defined,  as
previous  risk  assessment  efforts  have  been  primarily  directed  towards
exposures from  toxicants  in ambient air or  water  where  lifetime exposure is
assumed.  Animal  data  used for  AIS  estimates  generally include  exposures
with  durations  of  30-90 days.    Subchronlc  human data are  rarely  available.
Reported exposures  are  usually from chronic  occupational exposure  situations
or from reports of  acute accidental exposure.

    The  AIC,  acceptable  intake  chronic,  is similar in  concept  to the  ADI
(acceptable dally   intake).   It  is  an  estimate of an  exposure  level  that
would not  be  expected  to  cause adverse  effects  when  exposure occurs  for  a
significant portion of the  Hfespan  [see  U.S. EPA (1980) for a discussion of
this  concept].  The AIC  is route specific and  estimates  acceptable exposure
for a given route with  the  implicit  assumption  that exposure by other  routes
is Insignificant.

    Composite  scores   (CSs) for  noncarcinogens  have also  been  calculated
where data  permitted.   These values are used for  ranking  reportable  quanti-
ties; the methodology for their development  1s explained 1n U.S. EPA (1983).

    For compounds for which there  is  sufficient  evidence of  carcinogenlcity,
AIS  and AIC  values  are not derived.   For  a discussion of risk  assessment
methodology for  carcinogens refer  to  U.S.  EPA  (1980).   Since cancer is  a
process  that  1s not characterized  by  a threshold, any  exposure contributes
an increment  of  risk.   Consequently,  derivation  of AIS  and  AIC values would
be inappropriate.   For  carcinogens, q-j*s  have  been  computed  based on  oral
and inhalation data if available.
                                      111

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                                   ABSTRACT
    In  order  to  place the  risk  assessment  evaluation  1n proper  context,
refer  to  the preface  of   this  document.  The  preface outlines  limitations
applicable to all documents of  this  series as  well  as the appropriate Inter-
pretation and use of the quantitative estimates presented.

    A  number  of  subchronlc  Inhalation  studies  1n  experimental animals  are
available  which  suggest   threshold  exposure  levels  for  liver  damage  and
neurological  Impairment.  An AIS for Inhalation  of  153.4  mg/day Is  estimated
from  these studies.   No chronic exposure  data are available;  therefore,  an
AIC of 15.3 mg/day has  been estimated  based  on the  subchronlc  studies.  This
estimate should be reviewed when adequate  chronic data become  available.   No
Information concerning  consequences  of oral  exposure  to  methyl  ethyl  ketone
could  be  located.   As  a result, neither a AIS or  AIC for  oral  exposure  are
presented.  A  CS of  8.8   was  calculated  for  methyl  ethyl  ketone  based  on
fetotox1c1ty  In rats exposed by Inhalation.
                                      1v

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                               ACKNOWLEDGEMENTS


    The  Initial  draft  of  this  report  was  prepared  by Syracuse  Research
Corporation  under  Contract No.  68-03-3112  for  EPA's  Environmental  Criteria
and  Assessment  Office,  Cincinnati,   OH.   Dr.  Christopher  DeRosa and  Karen
Blackburn were the Technical  Project  Monitors  and  Helen Ball  was the Project
Officer.  The final documents  1n  this series  were  prepared for the Office of
Emergency and Remedial Response, Washington, DC.

    Scientists from  the  following U.S. EPA offices  provided  review  comments
for this document series:

         Environmental Criteria and Assessment Office, Cincinnati, OH
         Carcinogen Assessment Group
         Office of Air Quality Planning and Standards
         Office of Solid Waste
         Office of Toxic Substances
         Office of Drinking Water

Editorial review for the document series was provided by:

    Judith Olsen and Erma Durden
    Environmental Criteria and Assessment Office
    Cincinnati, OH

Technical support services for the document series  was provided by:

    Bette Zwayer, Pat Daunt, Karen Mann and Jacky Bohanon
    Environmental Criteria and Assessment Office
    Cincinnati, OH

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                             TABLE OF  CONTENTS

                                                                       Page

1.   ENVIRONMENTAL CHEMISTRY AND FATE	    1

2.   ABSORPTION FACTORS IN HUMANS AND  EXPERIMENTAL ANIMALS 	    3

    2.1.   ORAL	    3
    2.2.   INHALATION	    3

3.   TOXICITY IN HUMANS AND EXPERIMENTAL ANIMALS 	    4

    3.1.   SUBCHRONIC	    4

           3.1.1.   Oral	    4
           3.1.2.   Inhalation	    4
    3.2.   CHRONIC,
           3.2.1.   Oral	    6
           3.2.2.   Inhalation	    6

    3.3.   TERATOGENICITY AND OTHER REPRODUCTIVE EFFECTS	    6
           3.3.1.   Oral	    6
           3.3.2.   Inhalation	    6

    3.4.   TOXICANT INTERACTIONS	    7

4.  CARCINOGENICITY 	    8

    4.1.   HUMAN DATA	    8

           4.1.1.   Oral	    8
           4.1.2.   Inhalation	    8
    4.2.   BIOASSAYS.
           4.2.1.   Oral	    8
           4.2.2.   Inhalation	    8

    4.3.   OTHER RELEVANT DATA	    8
    4.4.   WEIGHT OF EVIDENCE	    9

5.  REGULATORY STANDARDS AND CRITERIA 	   10
                                     v1

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                          TABLE OF CONTENTS  (cont.)

                                                                        Page

 6.   RISK ASSESSMENT	    11

     6.1.   ACCEPTABLE  INTAKE SUBCHRONIC (AIS)  	    11

            6.1.1.    Oral	    11
            6.1.2.    Inhalation	    11

     6.2.   ACCEPTABLE  INTAKE CHRONIC (AIC)	    13

            6.2.1.    Oral	    13
            6.2.2.    Inhalation	    13

     6.3.   CARCINOGENIC POTENCY (q-j*)	    13

            6.3.1.    Oral	    13
            6.3.2.    Inhalation	    13

 7.   REFERENCES	    14

APPENDIX: Summary Table for  Methyl  Ethyl Ketone	    17

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                             LIST  OF  ABBREVIATIONS

ADI                     Acceptable dally Intake
AIC                     Acceptable intake chronic
AIS                     Acceptable Intake subchronlc
BCF                     Bloconcentration factor
CS                      Composite score
61                      Gastrointestinal
LOAEL                   Lowest-observed-adverse-effect level
MED                     Minimum effective dose
NOAEL                   No-observed-adverse-effect level
NOEL                    No-observed-effect level
ppm                     Parts per million
RQ                      Reportable quantity
RV(j                     Dose-rating value
RVe                     Effect-rating value
SGPT                    Serum glutamlc pyruvlc transamlnase
STEL                    Short-term exposure limit
TLV                     Threshold limit value
TWA                     Time-weighted average
                                     V111

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                     1.  ENVIRONMENTAL CHEMISTRY AND FATE

    The relevant  physical  and chemical properties  and  environmental  fate of
methyl ethyl ketone (CAS No. 78-93-3) are summarized below:
Chemical class:
Molecular weight:
Vapor pressure at 20°C:
Water solubility at 20°C:
Log octanol/water
partition coefficient:
B1oconcentrat1on factor:
Half-life 1n air:
Half-life 1n water:
aliphatic ketone
72.1
77.5 mm Hg
268 g/8.

0.26
0.33 (estimated)
14 hours
~ days
Verschueren, 1983
Verschueren, 1983
Lande et al., 1976

Verschueren, 1983

Graedel, 1978
Lande et al., 1976
    The  BCF  for  methyl  ethyl  ketone  was  estimated  from  the  octanol/water
partition coefficient  value  given 1n  the  table and  the  regression  equation
developed by Velth et al. (1979).
    The half-life of methyl  ethyl  ketone  1n aquatic media was not located 1n
the  available  literature.   However,  1n most  surface waters,  this  compound
may  blodegrade  almost  completely within  10 days  (Lande  et  al.,  1976).   The
evaporative half-life from water  was calculated to  be ~6  days (Lande et al.,
1976). However, use of the Mackay and  Wolkoff  (1973)  equation for estimating
the  evaporative  half-life of  this  compound, which  cannot be  classified  as
"slightly soluble," remains questionable.
    Pertinent data  regarding the fate  and  transport  of  methyl  ethyl  ketone
In  soil  could  not  be located  1n the  available  literature.   Based on  Us
relatively  high  water  solubility and  low  octanol/water  partition  coeffi-
cient,  methyl   ethyl  ketone  1s  expected  to  have  a  high  soil  mobility.
                                      -1-

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The two other  processes  that may account for  the  significant  loss  of methyl
ethyl   ketone  from  soil  are volatilization  and blodegradatlon.  By  analogy
from aquatic  media, the  half-life  of  methyl  ethyl ketone  1n soils  can  be
speculated to be about  a few days.
                                     -2-

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           2.   ABSORPTION  FACTORS  IN  HUMANS  AND  EXPERIMENTAL  ANIMALS
2.1.   ORAL
    Quantitative data on  the  oral absorption of methyl  ethyl  ketone are not
available, but  absorption from  the  61 tract  can  be  Inferred  from  systemic
toxic effects observed after acute oral administration (Lande et al., 1976).
2.2.   INHALATION
    Quantitative data on  the pulmonary  absorption  of  methyl  ethyl  ketone are
not available,  but  absorption from  the lungs  can be  Inferred  from  systemic
toxic  effects  observed  after  acute   and   subchronlc   Inhalation  exposures
(Lande et al., 1976).
                                      -3-

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                3.   TOXICITY  IN  HUMANS  AND  EXPERIMENTAL  ANIMALS
3.1.   SUBCHRONIC
3.1.1.   Oral.   Pertinent  data  regarding  the  effects  on  humans  or  experi-
mental animals  of  oral  exposure to methyl ethyl  ketone could  not be located
1n the available literature.
3.1.2.   Inhalation.   The subchronlc   Inhalation  studies  on  methyl  ethyl
ketone are  summarized  1n  Table  3-1.   Cavender  et  al. (1983)  exposed  both
sexes of  rats to methyl  ethyl  ketone  at concentrations of 0,  1250,  2500 or
5000  ppm,  6  hours/day, 5  days/week,  for 90 days.   There  were  no treatment-
related  effects at  the 1250 ppm level;  SGPT  activity  In  female  rats  was
elevated  at  the 2500 ppm  level.   At  the  5000  ppm  level, effects  were  more
severe  and  Included  depressed  mean  body  weight;   slight  but  significant
Increases  In  liver  weight,  I1ver-to-body weight  ratio,  and  I1ver-to-bra1n
weight ratio;  significantly  decreased SGPT  activity;  and  Increased alkaline
phosphatase,  potassium  and glucose values  1n  treated  females.   A  NOAEL  for
Increased SGPT  activity of 2500 ppm of  methyl  ethyl ketone  can be suggested
for rats from this study.
    Exposure  of  rats  to methyl  ethyl  ketone  at  a level of 200 ppm, 12 hours/
day,  7  days/week  for  24  weeks  resulted  1n   slight  neurological  effects
visible  only  at 4 months of treatment  (Takeuchl  et  al.,  1983), but exposure
of  rats  to  1125 ppm continuously  for  5  months  did not result In neuropathy,
defined  1n terms  of  paralysis  (Salda  et al., 1976).   In both studies, only a
single toxlcologlcal  endpolnt,  either  motor  nerve conduction velocity, mixed
nerve conduction  velocities, or  distal  motor latency (Takeuchl  et al., 1983)
or paralysis  (Salda et  al., 1976), was examined.
                                      -4-

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                                                                              TABLE  3-1

                                                   Subchronlc Inhalation Toxlclty Testing of Methyl Ethyl Ketone*
    Species/Strain       Sex          Number
                                   at  Start
                                    Exposure
                                                                       Effects
                                                                                              Reference
    Rats/F344
H/F
    Rats/W1star
i
    Rats/NR
    Rats/NR
    Rats/Sherman
    Guinea  ptgs/NR
    Guinea  pigs/
    mixed strains
NR
NR
H/F
NR
15/sex/
exposure
level
          8/exposure
          level
NR
25
15/sex/
exposure
level

15
          10/dose
          level
0. 1250. 2500 or 5000 ppm.
6 hours/day, 5 days/week.
for 90 days
                 0 or  200 ppm.  12  hours/day.
                 7 days/week,  for  24 weeks
0 or 1125 ppm continuously
for 5 months
0 or 235 ppm, 7 hours/day,
5 days/week, for 7 weeks
0. 125. 250. 500 or 1000
ppm, for 30 days (hours/day
and days/week,  NR)

0 or 235 ppm, 7 hours/day,
5 days/week, for 7  weeks
                 0.  125,  250,  500  or  1000
                 ppm,  for 30 days  (hours/day
                 and days/week.  NR)
No neuropathologlc or hlstopathologlc changes
and no effect on clinical parameters or growth
at the 1250 ppm level.  At the 2500 ppm level.
female rats had elevated SGPT activity.  At the
5000 ppm level, treatment-related effects In-
cluded depressed mean body weight; slight but
significant Increases In liver weight, liver to
body weight ratio, and liver to brain weight
ratio; significantly decreased SGPT activity;
and Increased alkaline phosphatase, K. and
glucose values In treated females.

No effect on body weight; significantly
Increased motor nerve conduction velocity and
mixed nerve conduction velocities after 4 weeks
of exposure, but not after 24 weeks; signif-
icantly decreased distal motor latency after
4 weeks of exposure, but not after 24 weeks.

No neuropathy, defined tn terms of paralysis,
was observed.  No other toxlcologlcal endpolnts
were evaluated.

No significant difference from controls In
growth, hematologtcal or pathological examina-
tion.

No significant hlstopathologlcal changes In
lung, liver or kidney.
No significant difference from controls In
growth, hematologlcal or pathological examina-
tion.

No statistically significant deviation from
controls In body, liver or kidney weights.
Cavender et al..  1983
                                                                                        TakeucM  et  al..  1983
Salda et al.. 1976
LaBelle and Brleger,
1955
                                                                                                                                          Mellon Institute, 1950
                                                                                                                   LaBelle and Brleger,
                                                                                                                   1955
                                                                                        Mellon Institute,  1950
    *PurHy  of compound was not  reported

    NR  =  Not  reported

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    LaBelle and BMeger  (1955) observed  no  effects  of  exposure to 235 ppm of
methyl  ethyl   ketone,  7  hours/day,   5  days/week,  for  7  weeks,  on  growth,
hematological   or pathological parameters  of  rats  and  guinea pigs.  Likewise,
exposure to 0,  125,  250, 500 or 1000  ppm for  30 days had  no  effect  on rats
and guinea pigs (Mellon Institute,  1950).
3.2.   CHRONIC
3.2.1.   Oral.   Pertinent  data  regarding  the  chronic  oral  toxicity  of
methyl ethyl  ketone  to humans or  experimental  animals could  not be  located
in the available literature.
3.2.2.   Inhalation.    Pertinent   data   regarding  the   chronic   inhalation
toxidty of methyl ethyl  ketone  to humans  or experimental  animals  could not
be located in  the available literature.
3.3.   TERATOGENICITY AND OTHER REPRODUCTIVE EFFECTS
3.3.1.   Oral.  Pertinent  data regarding the teratogenicity of methyl  ethyl
ketone following  oral  administration could  not  be  located  in  the  available
literature.
3.3.2.   Inhalation.   Schwetz et al.  (1974) exposed pregnant  Sprague-Dawley
rats  to methyl  ethyl  ketone by inhalation at levels of  1000 or  3000  ppm for
7  hours/day  on days  6-15 of gestation.  There  was no maternal  toxidty  at
either  exposure  level.   Somewhat   decreased fetal  body measurements  (body
weight  and cr,own-to-rump  length)  were  seen at  the  lower but  not  at  the
higher  exposure level.   At the 1000 ppm  level,  a significant  increase  in
litters having fetuses  with skeletal abnormalities was  seen;  however,  there
was  no  significant   increase  in  specific  gross,   soft-tissue   or  skeletal
anomalies.  At  the 3000  ppm level, a  significant  Increase  in  litters having
fetuses with  gross  external anomalies or internal  soft-tissue  anomalies  was
seen.
                                      -6-

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3.4.   TOXICANT INTERACTIONS
    Combined  exposure  to  100  ppm of  n-hexane  and  200  ppm of  methyl  ethyl
ketone  for  24 weeks  resulted  In neurotoxic  effects (defined as  changes  1n
motor nerve  conduction  velocity, distal  motor  latency  and mixed  nerve con-
duction velocities)  1n  rats  that were not observed  when  either  chemical was
tested  by  Itself  (Takeuchl et a!.,  1983).   Hewitt  et al.  (1983)  found that
methyl  ethyl  ketone  potentiated the  hepatotoxlc  response of chloroform  1n
rats.  There was a  positive  significant  correlation  between the  carbon chain
length  of  ketones  and   the  severity  of  the potentiated  chloroform-Induced
liver damage.
                                      -7-

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                              4.   CARCINOGENICITY
4.1.   HUMAN DATA
4.1.1.   Oral.  Pertinent data  regarding  the  carcinogenic effects  on  humans
as a  result  of  oral  exposure to methyl ethyl ketone  could  not  be located 1n
the available literature.
4.1.2.   Inhalation.   Pertinent  data  regarding the  carcinogenic effects  on
humans as  a  result of  Inhalation  exposure to methyl ethyl  ketone  could  not
be located 1n the available literature.
4.2.   BIOASSAYS
4.2.1.   Oral.   Pertinent  data   regarding   the   carcinogenic   effects   on
experimental  animals  as  a  result of  oral exposure  to methyl   ethyl  ketone
could  not  be located  1n the available  literature.   Methyl ethyl  ketone Is
not scheduled for  carclnogenlcHy  testing  by  the  National Toxicology Program
(NTP, 1983).
4.2.2.   Inhalation.   Pertinent  data  regarding the  carcinogenic effects  on
experimental  animals  as  a result  of  Inhalation  exposure  to  methyl  ethyl
ketone  could not  be  located  1n  the  available   literature.   Methyl  ethyl
ketone 1s  not scheduled  for carclnogenlcHy testing  by  the  National Toxicol-
ogy Program (NTP, 1983).
4.3.   OTHER RELEVANT DATA
    Schwetz  et  al.  (1974)  concluded  that In  rats   methyl  ethyl  ketone  Is
embryotoxlc,  fetotoxlc   and  potentially  teratogenlc  at  exposure  levels  of
1000  or  3000 ppm  by  Inhalation for  7  hours/day  on  days 6-15  of gestation.
There were no apparent effects on dams at either exposure level.
    Pertinent data  regarding the  mutagenldty  of  methyl ethyl  ketone  could
not be located In the available literature.
                                      -8-

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4.4.   WEIGHT OF EVIDENCE
    Methyl ethyl ketone  has  not  been tested for cardnogenldty  by  the  oral
or  Inhalation  routes.   No  tumors were observed during  pathological  examina-
tions 1n  subchronlc tox1c1ty tests  (see Section 3.1.2.).   IARC  has  not  eval-
uated  the risk  to humans  associated with  oral  or  Inhalation exposure  to
methyl  ethyl   ketone.    Applying  the  criteria proposed   by  the  Carcinogen
Assessment Group of the  U.S.  EPA for evaluating weight of evidence  (Federal
Register,  1984),  no  data  were  available regarding  the   cardnogenldty  of
methyl  ethyl  ketone 1n  humans  or animals, and the  chemical  1s  most  appro-
priately designated a  Group D - Not Classified  chemical.
                                      -9-

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                     5.   REGULATORY  STANDARDS  AND  CRITERIA

    ACGIH  (1983)  set a  TLV-TWA of  200 ppm  (590 mg/m3) and  a STEL  of  300
ppm (885  mg/m3)  for methyl ethyl  ketone.   The basis for these standards  is
the minimization  of eye  and  nose  irritation  rather than the  prevention  of
systemic toxic effects (ACGIH, 1980).
    The OSHA  standard  for methyl ethyl  ketone  is 200 ppm (590  mg/m3)  as  an
8-hour TWA for a 40-hour work  week (Code of Federal Regulations, 1981).
    ACGIH (1980) summarized the  standards  in  other  countries  as follows:  200
ppm  in West  Germany  (1974);  150  ppm  in  Sweden  (1974);  100  ppm in  East
Germany (1973);  and 100  ppm  in USSR  (1966),  Yugoslavia (1971) and  Hungary
(1974).
                                     -10-

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                              6.   RISK  ASSESSMENT
6.1.   ACCEPTABLE INTAKE SUBCHRONIC (AIS)
6.1.1.   Oral.   The  lack  of subchronlc  oral  toxldty  data  precludes  the
derivation of an AIS for subchronlc exposure to methyl ethyl  ketone.
6.1.2.   Inhalation.   Several  subchronlc Inhalation  studies  have been  done
on  methyl  ethyl  ketone.   Two  of  these  studies   are  not  useful  for  risk
assessment, the study by Salda et  al.  (1976)  1n which only one toxlcologlcal
endpolnt was  evaluated  and  the   study  by Mellon  Institute  (1950) In  which
complete exposure data  were not  evaluated  and a short duration  of  exposure
(30 days) was used.
    A NOEL of 235 ppm for  methyl  ethyl  ketone In  rats and  guinea  pigs  can be
suggested from the study of  LaBelle and  Brleger (1955).  For  Identifying the
toxic  threshold  for methyl  ethyl  ketone,  the  studies  by  Cavender  et  al.
(1983) and Takeuchl  et  al. (1983) are most useful, as both  studies define  a
NOAEL.  NOAELs of 2500  ppm of methyl  ethyl ketone  for Increased  S6PT  activ-
ity 1n female rats  {Cavender et  al.,  1983) and 200 ppm for  temporary  slight
neurological  effects 1n  rats (Takeuchl  et  al., 1983) can be  suggested  from
these  studies.   A   LOAEL  of  1000 ppm  for  skeletal abnormalities  1n  rat
fetuses (Schwetz et  al.,  1974) must also be  considered.
    The corresponding doses  for  rats   1n  units of  mg/kg/day for  the NOEL of
235 ppm (LaBelle and Brleger, 1955), the  NOAELs of  200 ppm (Takeuchl et  al.,
1983)  and  2500  ppm (Cavender  et  al.,  1983),  and  the  LOAEL of  1000  ppm
(Schwetz  et al., 1974)  are 107.3, 219.1, 978.1 and 639.0  mg/kg/day, respec-
tively.  The  equation and calculations  are as  follows:

              dA (mg/kg/day) = C  (mg/m3) x E  (hours/24 hours) x
                     D  (days/7 days)  x IR (mVday)  *  WA (kg)
                                     -11-

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where

    d/y  =  exposure  dose  for  the  experimental  animal  1n  units  of
         mg/kg/day;

    C =  concentration of toxicant 1n units of mg/m3;

    E =  number  of  hours/day that the  animals were  exposed  divided by
         24 hours;

    0 =  number of days/week that the animals were exposed;

    WA = body weight of the experimental animal 1n kg; and

    IR = Inhalation rate of the experimental animal in units of mVday.


For the NOEL of 235 ppm:

    693.1 mg/m3 x 7 hours/24 hours x 5 days/7 days x 0.26 mVday -r 0.35 kg =
    107.3 mg/kg/day


For the NOAEL of 200 ppm:

    589.9 mg/m3 x 12 hours/24 hours x 7 days/7 days x 0.26 mVday -=• 0.35 kg =
    219.1 mg/kg/day


For the NOAEL of 2500 ppm:

    7373.8 mg/m3 x 6 hours/24 hours x 5 days/7 days x 0.26 mVday * 0.35 kg =
    978.2 mg/kg/day


For the LOAEL of 1000 ppm:

    2949.5 mg/m3 x 7 hours/24 hours x 7 days/7 days x 0.26 mVday * 0.35 kg =
    639.1 mg/kg/day


    The NOAEL of 200 ppm  (219.1 mg/kg/day)  is  chosen to derive an inhalation

AIS, as  it  is  the largest NOEL or NOAEL dose  that  1s  less  than  the LOAEL of

1000 ppm  (639.0 mg/kg/day)  for  skeletal abnormalities  1n rat  fetuses.   An

uncertainty factor  of  100 is  applied  to the animal dose  of  219.1  mg/kg/day

to  convert  animal  to human  data  and to protect  the more  sensitive Individ-

uals of  a  population.   This  results  in an AIS  of 2.191 mg/kg/day  or  153.4

mg/day for a 70 kg human.
                                     -12-

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6.2.   ACCEPTABLE INTAKE CHRONIC (AIC)
6.2.1.   Oral.   The  lack  of  chronic  oral  toxlclty  data  precludes  the
derivation of an AIC for chronic exposure to methyl ethyl ketone.
6.2.2.   Inhalation.  There  are no chronic  studies  available from  which to
derive  a  chronic   Inhalation   Interim  ADI  for  methyl  ethyl   ketone.   The
TLV-TWA  of  200 ppm  (ACGIH,  1983)  cannot be  used  to derive an  AIC,  as this
criterion 1s  based  on  eye and  nose Irritation  rather  than  on systemic toxic
effects.  The subchronlc  Inhalation  study  by  Takeuchi  et  al.  (1983),  how-
ever,  can  be used  to derive  this  value.  An additional safety  factor  of 10
must  be  applied to  the  AIS  of 2.191  mg/kg/day  or 153.4 mg/day  for  a  70 kg
human  to  convert   from  subchronlc  to  chronic  data.   This   results  1n  an
Inhalation AIC of 0.2191  mg/kg/day or  15.34 mg/day for a 70 kg human.
    An  RQ  was  calculated  based  on   fetotoxlclty  (Schwetz  et  al.,  1974)
observed  In  rats exposed  to methyl  ethyl  ketone at  1000  ppm  (2949 mg/m3)
for  7 hours/day- on  days  6-15  of gestation.  A  human  MED was calculated  by
expanding  to continuous  exposure,  assuming  a  human  breathing  rate of  20
mVday  and  an  absorption efficiency  of 0.5,  and  applying  an  uncertainty
factor of  10 to extrapolate  from subchronlc  to chronic exposure.   A  human
MED  of  860.1 mg/day was calculated,  corresponding  to an  RV,  of 1.1.   The
fetotoxlclty  observed  at  this  exposure corresponds to  an  RV   of  8.  A  CS
of 8.8 1s calculated as  the product of RV. and RV .
                                         d       e
6.3.   CARCINOGENIC POTENCY (q *)
6.3.1.   Oral.  The  lack  of  oral  cardnogenlcity data precludes  the  deriva-
tion of a carcinogenic  potency for  oral  exposure to methyl  ethyl  ketone.
6.3.2.   Inhalation.  The  lack  of  Inhalation  cardnogenlcity  data precludes
the derivation  of  a carcinogenic potency for  Inhalation exposure to methyl
ethyl ketone.
                                     -13-

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                                7.  REFERENCES

AC6IH  (American  Conference  of Governmental  Industrial  Hygienists).   1980.
Methyl Ethyl  Ketone.   Documentation of  the  Threshold Limit Values,  4th  ed.
with supplements  through 1983.  p. 279.

ACGIH  (American  Conference  of Governmental  Industrial  Hygienists).   1983.
Threshold  Limit  Values  for  Chemical  Substances and  Physical  Agents  in  the
Workroom Environment with Intended Changes for 1984.  Cincinnati, OH.

Cavender, F.L., H.W. Casey,  H.  Salem,  J.A.  Swenberg and E.J.  Garalla.  1983.
A  90-day vapor  inhalation  toxicity  study  of  methyl  ethyl  ketone.   Fund.
Appl. Toxicol.  3(4): 264-270.

Code  of   Federal  Regulations.   1981.   OSHA  Safety  and Health  Standards.
Subpart Z - Toxic and Hazardous Substances.  29 CFR 1910.1000.

Federal  Register.   1984.   Environmental Protection  Agency.   Proposed Guide-
lines for Carcinogenic Risk Assessment.  49 FR 46294-46299.

Graedel,  T.E.  1978.  Chemical  Compounds  in  the Atmosphere.   Academic Press,
NY.  p. 187.

Hewitt,  W.R.,  E.M.   Brown  and  G.L.  Plaa.   1983.   Relationship between  the
carbon  skeleton   length  of  ketonic  solvents  and  potentiation  of  chloro-
form-induced hepatotoxicity  in  rats.   Toxicol.  Lett.   16(3-4):  297-304.   (CA
98:22111146)
                                     -14-

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LaBelle, C.W. and  H.  Brleger.   1955.   Vapour  toxldty of a composite solvent
and  Us  principal  components.  Arch.  Ind.  Health.   12: 623-627.   (Cited  1n
Lande et al., 1976)

Lande,  S.S., P.R.  Durkln,  O.H.   Christopher,  P.M.  Howard  and  J.  Saxena.
1976.    Investigation   of   Selected   Potential   Environmental  Contaminants:
Ketonlc  Solvents.  Prepared  under  Contract  No.  68-01-3100.   U.S.  EPA,  Office
of Toxic Substances,  Washington, DC.   EPA 560/2-76-003.

Mackay,  D.  and  A.W.  Wolkoff.   1973.   Rate  of  evaporation  of low solubility
contaminants  from  water bodies  to atmosphere.   Environ.  Sc1. Techno!.   7:
611-614.

Mellon  Institute.   1950.   Methyl  Ethyl  Ketone,  Report 14-33,  unpublished,
Union Carbide Corporation.   (Cited 1n Lande  et al.,  1976)

NTP  (National  Toxicology Program).   1983.   Chemicals on  Standard  Protocol.
Management Status Report dated 12/5/83.

Salda,  K.,  J.R. Mendell  and H.S.  Weiss.  1976.   Peripheral nerve  changes
Induced  by  methyl  n-butyl   ketone  and  potentlatlon  by methyl ethyl  ketone.
J. Neuropathol.  Exp.  Neurol.  35:  207-225.

Schwetz, B.A.,  B.K.J.  Leong and  P.J.  GehMng.   1974.   Embryo- and  fetotox-
Iclty of  Inhaled carbon tetrachloMde,  1 ,l-d1chloroethane and methyl  ethyl
ketone In rats.   Toxlcol. Appl.  Pharmacol.  28(3): 452-464.
                                     -15-

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Takeuchl, Y.,  Y.  Ono,  N. Hlsanaga,  et  al.  1983.  An  experimental  study of



the combined effects of  n-hexane and methyl ethyl  ketone.   Br.  J.  Ind.  Med.



40(2): 199-203.







U.S.  EPA.   1980.   Guidelines and  Methodology  Used  1n  the Preparation  of



Health  Effects  Assessment   Chapters  of  the  Consent  Decree  Water  Quality



Criteria.  Federal Register.  45: 79347-79357.







U.S.  EPA.   1983.   Methodology and Guidelines  for  Reportable Quantity Deter-



minations  Based   on  Chronic  Toxlclty  Data.   Prepared  by  the  Environmental



Criteria and Assessment  Office,  Cincinnati,  OH,  OHEA  for  the Office of Solid



Waste and Emergency Response, Washington, DC.







Veith, G.D., D.L.  DeFoe  and B.V.  Bergstedt.   1979.  Measuring and estimating



the bloconcentratlon  factor of  chemicals  in fish.   J. Fish Res.  Board  Can.



36: 1040-1048.







Verschueren, K.   1983.   Handbook of  Environmental  Data on Organic Chemistry,



2nd ed.  Van Nostrand Reinhold Co., NY.  p.  850-852.
                                     -16-

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                                                  APPENDIX



                                    Summary  Table  for  Methyl  Ethyl  Ketone
Species
Inhalation
AIS rats
AIC rats
_;_, Maximum rats
-j composite
score
Oral
AIS NA
AIC NA
Experimental
Dose/Exposure

200 ppm
200 ppm
1000 ppm
(2949 mg/m3),
7 hours/day on days
6-15 of gestation
(RVd=l.l)

NA
NA
Effect Acceptable Intake
(AIS or AIC)

temporary slight 153.4 nig/day
neurological effects
temporary slight 15.34 mg/day
neurological effects
fetotoxlclty 8.8
(Rve=8)

NA ND
NA ND
Reference

Takeuchl
et al.,
Takeuchl
et al.,
Schwetz
et al..

NA
NA

1983
1983
1974



NA = Not applicable; ND = not derived

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