health and safety plan solid waste management unit assessment

METHYL ETHYL KETONE 41-15
41.3.2.2 Chronic Toxicologic Effects
Smith and Mayer (1032) investigated the effects of methyl ethyl
ketone on a group of factory workers using methyl ethyl ketone as a
solvent. Routes of exposure included both immersion of bare hands in
the solvent and inhalation of 300-600 ppm. No duration of exposure was
given. A number of workers developed severe dermatitis. Several
workers also experienced numbness in the fingers, arms and legs.
Symptoms disappeared when exposure to methyl ethyl ketone was
discontinued.
The potentiation of various haxacarbon neuropathies by methyl
ethyl ketone is of particular interest in cases of solvent abuse.
Altenkirch (1033) reported 25 cases of clinically severe toxic polyneuropathy
in people addicted to inhaling methyl ethyl ketone-containing
solvents. The peripheral motor defects took 2.5-3 years to
become apparent. The effects were considered to be due to an axonal
transmission disorder which destroyed peripheral and central axons
(0049).
Altenkirch (1004) also described what was known as the Berlin
Poisoning Affair. In 1974, a solvent manufacturer changed its formulation
to help stop inhalation abuse. The hexane content was reduced
from 31 to 16% and 11% methyl ethyl ketone was added as a denaturant.
An epidemic-like outbreak of 19 severe neuropathy syndromes occurred
soon after the new formulation was available to the public.
Neurological effects included considerable weight loss, muscular
weakness affecting all four extremities or paralysis of all four
extremities, extreme muscular atrophy, and respiratory disorders. In
some cases, visual disturbances occurred and facial nerves were
affected. Individuals examined up to 4 years after the incident still
exhibited muscular atrophy, muscular weakness and sensory defects.
This incident further supports findings that the neurotoxic properties
of hexane can be potentiated by methyl ethyl ketone.
A female shoe-factory worker developed sensorimotor neuropathy
after years of working with a glue containing 20% methyl ethyl ketone
and 8% hexane (1007). The woman developed sensory and motor neuropathy
in the lower limbs, and the absence of deep reflexes. This condition
slowly regressed once exposure to the solvent mixture ceased.
41.3.3 Levels of Concern
The EPA (1770) has established a Health Advisory for
noncarcinogenic risk for long-term exposure to methyl ethyl ketone of
8.6 mg/L in drinking.water.
The OSHA (298) standard is 200 ppm (590 mg/m3) averaged over an
a-hour work-shift. The ACGIH (3) recommends a threshold limit value of
200 ppm, with a short-term exposure limit of 300 ppm (885 mg/m3). The
threshold limit value was set to prevent injurious effects and minimize
complaints about odor and irritation (46).
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