The acute toxicity and irritancy of bis[2-(dimethylamino)ethyl]ether

Bis[2-(dimethylamino)ethyl]ether (DMAEE; CAS No 3033-62-3) is an industrial liquid chemical used principally as an amine catalyst. It was investigated for potential acute hazards. DMAEE is of moderate acute peroral toxicity with LD50 values in the rat of 1045 ml/kg and 1198 mg/kg in 2 separate tests and producing gastric injury. Dilution (25% in corn oil) had no significant influence; LD50 909 mg/kg. It is of moderately high acute percutaneous toxicity in the rabbit; LD50 values by 4 h occlusive contact are 348 mg/kg (male) and 535 mg/kg (female), and for 24 h 314 mg/kg (male and female). Dilution (20% DMAEE in water) did not influence lethal toxicity; LD50 363 mg/kg (male) and 481 mg/kg (female). Skin contact produced severe irritation and injury, notably erythema, edema, ulceration, desquamation and scab formation. Necrosis was produced in 5/6 rabbits with a 3-min occluded contact. DMAEE produced severe eye injury, with blepharo-conjunctivitis and corneal injury from undiluted and 10% aqueous DMAEE; threshold conjunctival effect occurred at 1% aqueous DMAEE. Vapor concentration was dependent on relative humidity, concentration increasing with decreasing humidity. A statically generated vapor atmosphere was not lethal to rats due to the accumulation of water vapor from expired air (mean DMAEE = 24 ppm; 6 h exposure). With a dynamically generated atmosphere, where relative humidity could be controlled, the 6 h LC50 to rats was 166 ppm (males and females). Signs included those of ocular and respiratory irritation. DMAEE is acutely hazardous by swallowing, skin and eye contact, and exposure to moderately high vapor concentrations. Appropriate protective and precautionary measures are reviewed.