Single doses by mouth to male albino rats resulted in an approximate LD50 of 3.0 gm./kg. This places 2-ethyl hexoic acid in Grade 3 of our oral toxicity rating system along with sorbic and lactic acids. The LD(sub 50) by skin absorption for guinea pigs in the 4 day contact period is 6.3 gm./kg. Slight dryness and cracking of the skin occurs with 10 gm./kg. after a 24 hour contact period. The undiluted material is in Grade 5 of our eye burn rating system as 0.001 ml. produces corneal necrosis of the rabbit eye. Undiluted and 100 dilutions in acetone cause etythema of the skin of rabbit bellies. The eye hazard is obvious and based on the above findings any prolonged contact with the skin should be avoided. No saturated vapor exposures were made because of the low vapor pressure which obviates any vapor hazard when the material is not heated.