Benzyldimethylamine

Endpoint summary

Description of key information

Different doses of undiluted test substance given per gavage to male rats resulted in LD50 oral:  0.65 ml (579 mg/kg bw);
Different doses applied to the dorsal skin of male rabbits resulted in LD50 dermal: 1.66 ml/kg (1477 mg/kg bw);
Whole body exposure of male and femle rats to different vapour concentrations for 4 hours resulted in LC50 inhal: 373 ppm (2052 mg/m³).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

579 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

2 052 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

1 477 mg/kg bw

Additional information

ACUTE ORAL TOXICITY

In an acute oral toxicity study undiluted test material was administered by gavage to groups of 5 male Wistar-derived rats of 90-120 g and 3-4 weeks of age. Following doses were tested: 0.5 , 1.0, 2.0 ml/kg bw (445, 890, 1780 mg/kg bw) Animals were observed daily for signs of toxicity over a 14-day postdosing period, at the end they were subjected to gross pathological examination. All animals died at a dose of 2.0 and 1.0 ml/kg bw, but only 1 of 5 at 0.5 ml/kg, indicating a steep slope to the response. Deaths occurred within 10 to 90 minutes after dosing, with the latency increasing as dosage decreased. Signs of toxicity included tremors and salivation which were seen within a few minutes after dosing. Autopsy examination of dead animals showed congestion and hemorrhages of the stomach, and intestinal congestion. Survivors of the 0.5 ml/kg bw group, sacrificed at the end of the 14 -day postdosing observation period, showed no gross abnormalities at autopsy. The LD50 was 0.65 ml/kg bw (resp. 579 mg/kg bw, Ballantyne1985).

ACUTE INHALATION TOXICITY

The acute inhalation toxicity of the test substance was studied in groups of 6 male and 6 female F344 rats per concentration

by 4-hours exposures to 25, 150, 277, 500 ppm (133, 769, 1532, 2771 mg/m³). A control group (2/sex) was exposed to filtered air only. Mortalities occurred at the highest concentration only, with all animals dying within 2 to 2.5 hours from the start of the exposure. Signs of toxicity included irritation, salivation labored breathing and urogenital wetness. During the 14 day postexposure, periorbital and perinasal red encrustations were observed and pathological changes determined in lungs and the upper respiratory tract at 500 and 277 ppm.

The LC50 was determined to be 373 ppm/4h (2052 mg/m³/4h, Ballantyne 1985)

ACUTE DERMAL TOXICITY

In an acute dermal toxicity study the undiluted test substance was applied to the clipped dorsal skin of groups containing 4 male rabbits/group at doses of 0.5, 1.0, 1.4, 2.0 ml/kg bw. The test material was maintained in contact with the skin by a polythene sheet held in place with an adhesive dressing. Animals were immobilized during a 24-hr occlusion period. At the end of the contact period the polythene sheeting was removed, the skin gently wiped clean, and the area inspected for signs of local inflamation. Animals were observed daily over a 14-day postapplication period for signs of toxicity. At the end of this time the survivors were sacrificed and subjected to autopsy examination. All animals died at the highest dose of 2.0 ml/kg bw, with a latency of up to 2 days. Signs of toxicity included tremors and hyperactivity. No signs of systemic toxicity were seen in animals following the application of 1.4 ml/kg bw and lower. On removal of the occlusive dressing, edema and necrosis were seen at the site of application of undiluted test substance to skin. This progressed to scab formation over the ensuing 14 days. Autopsy examination of the animals that died revealed a red mottled appearance to the liver and kidneys, but otherwise there were no abnormalities. The LD50 was determined to be 1.66 ml/kg bw (ca1477 mg/kg bw).

Justification for classification or non-classification

According to Regulation (EC) 1272/2008 (CLP/GHS) N,N-Dimethylbenzylamine is already classified 

acute oral toxicity: category 4 (H302); acute dermal toxicty: category 4 (H312); acute inhalation toxicity: category 4 (H332).

However, based on the available data on acute inhalation toxicity, regarding Regulation (EC) 1272/2008 (CLP/GHS), classification in category 3 (acute inhalation toxicity) and labelling with H331 is required.