The acute toxicity and primary irritancy of 2,4-pentanedione.

2,4-Pentanedione was found to have acute peroral LD50 values (with 95% confidence limits) in the rat of 0.78 (0.66-0.91) ml/kg for males and 0.59 (0.51-0.70) ml/kg for females, and acute percutaneous LD50 values by 24 hr occluded contact on the rabbit of 1.41 (0.80-2.49) ml/kg for males and 0.81 (0.59-1.12) for females. Lt50 values for exposure of rats to saturated vapor atmospheres were 52 min (7060 ppm) for males and 55 min (7912 ppm) for females. The 4 hr LC50 value for rats was 1224 (1063-1409) ppm for combined male and female data. A 4 hr occluded contact with 0.5 ml produced mild local erythema and edema. Instillation of 0.1 ml into the inferior conjunctival sac, produced mild conjunctivitis of less than 24 hr duration without corneal injury.