General Animal and Aquatic Toxicity - The Toxicology of Methanol - page 79

TABLE 4.2 Mortality from Dermal Exposure to Methanol in Various
Animal Species
Species LD 50 , mg/kg Comments References

Rat 35,000-45,000 Eulner and Gedicke (1955)

Rabbit 15,840 Union Carbide (1994)

Rabbit 15,800 Lington and Bevan (1994)

Rabbit 17,000 Carnegie-Mellon (1981)

Monkey 1,600 Occluded McCord (1931)

45,000mg/kg bw (Eulner and Gedicke, 1955). In rabbits, the dermal
LD 50 of about 15,840-17,000mg/kg bw has been reported (Carnegie-
Mellon, 1981; Union Carbide, 1994).
In rhesus monkeys, four daily doses (occluded) of 400mg/kg bw
methanol (total 1600mg/kg bwper day) caused sicknesswithin 24 hours,
and eventually death. After four daily doses of 1000mg/kg bwmethanol
(total 4000mg/kg bw), severe illness took place followed by death on the
second day. Rabbits and rats also exposed to methanol under occluded
conditions (doses not given) died. The rabbit appeared to be less
susceptible to methanol than the monkey or rat (McCord, 1931).
These dermal studies demonstrate that methanol can be absorbed
through the skin in rats, rabbit, and monkey in significant amounts to
cause toxicity and death, but based on the rodent data methanol would
be classified (Hazard category IV) as practically nontoxic or very low
toxicity by USEPA classification for dermal toxicity (USEPA, 2008).

4.2.3 Inhalation

Table 4.3 lists the mortality from single inhalation exposure to methanol
in various animal species.
High concentrations of methanol in air are needed to produce
lethality in rodents. The LC 50 of methanol in rats was reported to be
between 64,000 and 145,000 ppm for exposures ranging from 8 to
1 hour, respectively. In rodents for inhalation toxicity, methanol would
be classified (Hazard category IV) as practically nontoxic or very low
toxicity by USEPA (2008).