P.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

'44 pqcl E,0 -o 0

OFFICE OF

PESTICIDES AND TOXIC

SUBSTANCES

MEMORANDUM

SUBJECT : EPCRA Section 313 Delisting Petition : Absorption

Review for Methyl Ethyl Ketone (MEK )

FROM : Leonard C . Keifer, Ph .D ., FAIC

Chemis t

Metabolism and Carcinogenesis Section

Health Effects Branc h

Health and Environmental

Review Division (7403)

TO : Lorraine Randecker

Hazard Integrator

Analysis and Information Management Branch

Chemical Screening and Risk

Assessment Division (7402)

THRU : David Y . Lai, Ph .D .

Acting Section Chief

Metabolism and

Carcinogenesis Sectio n

Health Effects Branch

Health and Environmental

Review Division (7403)

I . INTRODUCTION

A petition was filed for delisting MEK from Section 313 TRI

reporting . At the request of the MEK work group a summary of the

absorption of MEK from the lung and GI tract and through the skin

is provided . The information presented is, for the most part,

taken from the ATSDR toxicological profile for MEK (ATSDR, 1992) .

II . CONCLUSIONS

MEK is well absorbed from the lung, GI tract, and skin .

Pulmonary uptake in humans ranged from 41% to 56% . Case reports

in humans and/or studies in rats demonstrate that MEK is absorbed

from the GI tract and the skin ; however, the available informatir- T-T=C~ nr~t- qllfficient to determine the percent of the dose absorbed .

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III . BASES FOR CONCLUSIONS

A . Lung : 2-Butanone (MEKI is well absorbed during inhalation exposure . Pulmonary uptake in humans ranged from 41% to 56%

of the inspired quantity (Liira et al . 1988a, 1988b, 1990 [all as

cited in ATSDR, 1992]) . Exercise increased the pulmonary uptake

because of the greater ventilatory rate (Liira et al . 1988b (as

cited in ATSDR, 19921) .

B . GI Tract : A woman who had metabolic acidosis after

having accidentally ingested 2-butanone [MEKI stored in a rum

bottle had a blood concentration of 95 mg/100 mL (13 .2 mM)

(Kopelman and Kalfayan 1983 (as cited in ATSDR, 1992]) .

Oral administration (gavage) of 1,690 mg 2-butanone [MEKI/kg

in rats resulted in a plasma concentration of 94 mg/100 mL at 4

hours (Dietz and Traiger 1979 [as cited in ATSDR, 1992]) . Within

18 hours, the plasma concentration decreased to 6 .2 mg/100 mL

(Dietz and Traiger 1979 [as cited in ATSDR, 1992]) .

These studies demonstrate that MEK is absorbed from the GI

tract ; however, the available information was not sufficient to

determine the percent of the dose absorbed .

C . Skin : Measurable (2 .54 to 13 btg/L) quantities of methyl

ethyl ketone appeared in expired air of adult humans 3 min

following dermal exposure to 100 mL of methyl ethyl ketone [MEKI

applied to 91 .5 CM2 Of skin (Wurster ; J Pharm Sci 54 : 554 ; 1965

[as cited in HSDB, 1997]) . Data were not available to determine

the percentage of the applied dose that was absorbed .

REFERENCES

ATSDR . 1992 . Toxicological Profile for 2-Butanone (MEK] . U .S .

Department of Health & Human Services . Public Health Section .

Agency for Toxic Substances and Disease Registry, Division of

Toxicology, Mail Stop E-29, 1600 Clifton Road, N .E ., Atlanta, GA

30333 .

HSDB . 1997 . Hazardous Substances Data Base Record for Methyl

Ethyl Ketone .

CC : Fred Metz (7406)

Daniel Bushman (7408)

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