health and safety plan solid waste management unit assessment

METHYL ETHYL KETONE 41-13
Patty & &,. (1028) describe the effects of airborn methyl ethyl
ketone on guinea pigs at concentrations of 0.33, 1.0, 3.3 or 10.0% for
up to 810 minutes. Signs of toxicity included irritation of the nose
and eyes. incoordination, narcosis, gasping and death. Necropsy
revealed emphysema, slight congestion of the brain and marked
congestion of the systemic organs, particularly the lungs.
Exposure of guinea pigs to 108 methyl ethyl ketone vapor for 30
minutes resulted in opaque corneas. Examination eight days later
showed that the eyes had returned to normal, indicating a reversibility
of the damage (1028).
It has been well established that ketones as a class can cause
narcosis at high concentrations (13,1029). However, it is believed
(1012) that ketones may also be capable of producing a modification of
behavior or impairment of judgement at lower concentrations. Geller a
A. (1012) evaluated the effect of low-level methyl ethyl ketone .
exposure on delayed match-to-sample tasks in the baboon. .Four juvenile
baboons were exposed to 100 ppm methyl ethyl ketone, 24 hours a day for
7 days. Accuracy of performance was minimally affected. However,'
extra responses during the delay period were recorded and the response
time was significantly increased. These effects were considered to be
an early manifestation of the incoordination and narcosis which are
observed at much higher concentrations.
Tham t& A. (1006) demonstrated that a component of the equilibrium
system, the vestibulo-ocular reflex (VOR), was depressed in rats
when methyl ethyl ketone was infused into the circulatory system at a
rate of 70 M/kg/minute for 60 minutes, resulting in blood levels of
100 ppm. Nystagmus (a rapid, involuntary movemnt of the eye ball) was
induced by accelerated rotation to study vestibular function.
Depression of the VOR is considered an early sign of intoxication prior
to the onset of a general depression of the central nemous system.
41.3.1.4.2 Chronic Toxicity
A subchronic inhalation study performed by Cavender a A. (1008)
exposed male and female Fischer 344 rats to 1250, 2500 or 5000 ppm
methyl ethyl ketone in a chamber for 6 hours/day, S days/week for 13
weeks. The only clinical observation was a decrease in mean body
weight in the group receiving 5000 ppm methyl ethyl ketone. Increases
in liver weight and liver to body weight ratios were noted in both
males and females in the 5000 ppm group and a depression of brain
weight in females in the 5000 ppm group at necropsy. No lesions were
found that could be attributed to methyl ethyl ketone'.
Methyl ethyl ketone has been shown to shorten the latency period
for the onset of neurotoxic effects of methyl butyl ketone and n-hexane
in a number of species. Altenkirch (1002) studied the response of the
nemous system to chronic repeated exposures of 10,000 ppm pure hexane,
10,000 ppm methyl ethyl ketone/n-hexane (ratio of 1:9) or 6000 ppm pure
methyl ethyl ketone in rats. Rotor neuropathy with giant swelling of
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