tert-butylamine

Endpoint summary

Description of key information

Acute Toxicity:
- oral: LD50: 464 mg/kg bw (rat);
- inhalation: 3.8 mg/L air (4h);
- dermal: > 2000 -< 3610 mg/kg bw;

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

464 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

3 800 mg/m³ air

Additional information

Oral:

In a study which was in large parts equivalent to methods described in OECD guideline 401, the LD50 for oral acute toxicity in rats was calculated as ca. 464 mg/kg body weight. Doses of 316, 464, 681 mg/kg bw of an aqueous solution were applied by gavage followed by a post dose observation period of 7 days. Main clinical signs observed were dyspnoea, apathy, staggering, tremors, piloerection, diarrhea, salivation, stretching, imbalance and poor general condition. At necropsy, haemorrhagic gastritis, bloody content of intestine, acute peritonitis, local adhesions of stomach and liver, single animals with acute serous peritonitis as a result of perforation of the stomach, single animals with very severe tymanitas, one animal with perforated duodenal ulcer, swollen margo plicatus were noted (BASF AG, 1985; reliability score: 2). Another study is reporting an LD50 of 44 mg/kg bodyweight in another rat strain. This study lacks many technical study designs such as vehicle, purity and was thus regarded as not assignable (Monsanto 1970; reliability score: 4). The same holds for another study in Sprague Dawley rats with a LD50 reported to be 80 mg/kg bw (Monsanto 1973; reliability score: 4). Another LD50 in Sprague Dawley rats reported an LD50 of 80 mg/kg bw. In this study evaluated as valid with restrictions, corn oil was reported as vehicle. It is known that lipophilic vehicles could enhance absorption and this lead to a more toxic response (Cheever 1982; reliability score: 2).

 

Inhalation:

Groups of ten male Sprague-Davley rats received single four hour exposures to vapor of tertiary butylamine. The post-exposure period was 14 days. A LC50 of 3.8 mg/L tertiary butylamine was determined. Signs of toxicity during exposure were ptosis, gasping, excessive lacrimation and bleeding from the oral and nasal regions in animals exposed to concentration greater than 3 mg/L. Some rats developed opaque areas on one or both lenses during the post-exposure period (2-4 mg/L). Necropsy of test animals showed lung hemorrhage and petechial hemorrhage of the thyme in all groups regardless of dose. Effects of the compound which increased with dosage beginning with exposures of 4 mg/L were hemorrhage of the scrotum, inflamed trachea and gaseous distension of the stomach (Monsanto 1992; reliability score: 2)

 

Additional data is available from an inhalation risk test (IRT) which meets generally accepted scientific principles.The inhalation of a saturated vapor-air mixture for 3 hours caused mortality on all 3 tested animals. Main clinical signs were violent attempts to escape, gasping, stretching convulsions, clonic-tonic convulsions, twitching, breath sounds, corneal opacity. At necropsy, slight lung oedema, petechial subpleural bleedings were observed (BASF AG, 1962; reliability score 2). In two further IRT with limited data provided, all animals died within 15 of exposure (Monsanto 1970 and 1973; reliability score: 4).

 

Dermal:

In two dermal studies LD50 of >2000 <3610 mg/kg bw and >7940 mg/kg bw were calculated. At necropsy lung and liver hyperemia, liver discoloration, enlarged gall bladder and gastrointestinal inflammation were observed. These studies showed that t-butylamine is practically non-toxic by skin contact (Monsanto 1970 and 1973; reliability score: 4).

 

Justification for classification or non-classification

EU classification according to Annex VI of Directive 67/548/EEC: Xn, R20/22