The acute toxicity and primary irritancy of glutaraldehyde solutions

Glutaraldehyde (CA, CAS Number 110-30-8), an aliphatic dialdehyde, has a wi de range of industrial, scientific, and medical applications. It is availab le in aqueous solutions, whose concentrations vary up to 50% (w/w) and from which there is a potential during use for skin and eye contact and exposur e to the vapor. The acute toxicity and primary irritancy of a wide range of CA concentrations were investigated to determine the differential hazards for such solutions. The acute peroral toxicity in the rat, expressed as mi of solution solution dosed, was moderate For solutions of 5% and above (LD5 0 range 0.88-3.25 ml/kg) and generally varied little for solutions up to 50 %. Solutions less than 5% CA were of slight toxicity (LD50 range 3.34-12.30 ml/kg for 1 and 2% solutions). When lethality was expressed as absolute am ount of GA dosed (mg GA/kg). there was a reciprocal relationship between th e concentration of GA solution dosed and LD50. This was confirmed in the mo use, which is more susceptible than the rat to acute peroral toxicity, The acute percutaneous toxicity of GA solutions to rabbits (24 h occlusion) was moderate (LD50 range 1.57-2.71 ml/kg) for 46 and 50% solutions. and slight for 25% GA solutions (8.80-16.00 ml/kg). At 15% and less, 16.0 ml/g was no t lethal. Exposures (4-8 h) of rats to saturated vapor atmospheres of CA ge nerated dynamically or statistically at ambient temperature (17-25 C) produ ced only transient peripheral sensory irritant effects to the eyes and resp iratory tract. In contrast, vapor atmosphere generated dynamically at eleva ted temperature (60 or 65 C) produce severe effects, including mortality (4 -h LC50 range 23.5-44.3 ppm). Histopathology in rats that died included exp osure concentration-related acute inflammation and necrosis in the nasal mu cosa, larynx, trachea, and bronchi. Standard primary skin irritation tests in the rabbit indicated severe skin irritation and necrosis at 45 and 50% G A; necrosis occurred with 1 and 4 h contact at 50% and at 4 h with 45%. Inf lammation was moderate at 25%, slight to moderate with 5 and 10% CA, minor at 2%, and threshold at 1%. Standard primary eye irritation tests showed 45 % GA to produce severe conjunctival and corneal injury, which was persisten t. At 2% CA corneal injury was mild. and at 5% marked. The lowest concentra tion producing corneal injury was 1.0%, and the no-effects concentration wa s 0.5%. The threshold for conjunctival effects was 0.2%. and the no-effects concentration 0.1%. At 1% GA, conjunctival hyperemia and chemosis were mod erate to marked, and became more severe with higher CA concentrations. The results suggest potential acute handling hazards with various concentration s of CA solutions and indicate industrial hygiene considerations.