Triethylamine

Endpoint summary

Description of key information

Acute oral toxicity: "industrial hygiene orientating investigation", BASF AG, report Nr. VI/389, 1960 comparable to the OECD Guideline 401, rats (m/f),doses: 15, 58, 230, 366, 580, 920 and 3660 mg/kg bw.
Acute dermal toxicity: Meyers and Ballantyne, 1997. Comparative acute and primary irritancy of various classes of amines, comparable to the OECD guideline 402; New Zealand Black rabbits, doses  0.5, 1.0 and 2.0 mL/kg bw.
Acute inhalation toxicity: "Triethylamine: Acute Inhalation (1-Hr. LC50) Study in Rats", International Research and Development Corporation, study report 214-060, 1995. According to the OECD Guideline 403. Actual concentrations: 2,450, 3,200, 4,000, and 5,050 ppm

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

730 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Dose descriptor:

LC50

Value:

7 220 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

580 mg/kg bw

Additional information

Acute toxicity:oral

Acute oral toxicity of triethylamine is moderate. The LD50 values concerning this endpoint were reported in a lot of studies and publications. In the available data set LD50 for triethylamine varies from 370 to 1470 mg/kg/bw in rodents. The BASF study in rats (1960) was chosen as the key study for this endpoint because of its well-conducted test design and well-documented results, which provides sufficient information to assess health effects, a clear dose dependent response (seven dose levels tested) and LD50 of 730 mg/kg bw which was calculated for both sexes. Hence, the study gives the critical information for the assessment of acute effects after oral exposure to the test substance.

Acute toxicity:dermal

The publication chosen (Meyers and Ballantyne, 1997) as the key study for acute dermal toxicity endpoint presents the results of acute toxicity and primary irritation studies for 43 amines of 9 chemical classes. The adverse effects caused by aliphatic amines are summarised from a variety of studies. Triethylamine caused severe skin damage and systemic toxic effects if applied to rabbits skin for 24 hours under occlusive conditions. In this study reviewed in the article triethylamine was tested in the concentrations allowing to derive the most realistic LD50 level. Mortality was observed within 2 weeks of dosing in 3 of 4 animals in the 1.0 mL/kg/bw dose group and in 2 of 4 animals in the 2.0 mL/kg/bw dose group. In 0.5 mL/kg/bw dose group no mortalities were observed. Mild to moderate skin irritation were the common observations.

Acute toxicity:inhalation

In the GLP and OECD compliant acute 1 -hour inhalation study (International Research and Development Corporation, 1995), the exposure of rats to triethylamine caused a clear dose-dependent response. Severe toxicity leading to death was observed among rats exposed to triethylamine via inhalation. Four measured exposure concentrations were used: 2,450, 3,200, 4,000, and 5,050 ppm. Rats showed labored breathing and tremors at all exposure levels; some also showed increased salivation and (at 3,200 ppm) excessive lacrimation. After 2,450 ppm all rats (5 male and 5 female) returned to normal by post-exposure day 5. At 3,200 ppm two female rats died immediately post-exposure, but the other 3 females and all 5 males returned to normal by post-exposure day 6. At 4,000 pm 9/10 rats died immediately after exposure, and at 5,050 ppm all 10 died immediately.

Mean body weight gains were normal after 2,450 ppm (for both male and female rats) and for female rats after 3,200 ppm. Male body weight gains were depressed during the first week after 3,200 ppm exposure, but all returned to normal by day 14. At necropsy, no macroscopic abnormalities were recorded for either the lowest or the highest exposure groups. At 3,200 ppm one male rat had bilateral corneal opacity. Four males and four females had discolored lungs after 4,000 ppm. 1 -hour LC50 was determined to be 3496 ppm (14270 mg/m³). For the purpose of classification and labelling this value can be extrapolated to 4 -hour exposure value by dividing by a factor of 2 and then can serve as key value (Guidance on the Application of Regulation (EC) No. 1272/2008).

In a supporting study (BASF, 1960) rats were inhaled to the vapour TEA-air-mixture during 8 minutes. All animals died within 4 minutes. Dyspnoea was observed as clinical symptom. There were no abnormalities found by gross pathology. Meyers and Ballantyne exposed two groups of rats by inhalation during 4 hours and 2 hours, respectively (Myers and Ballantyne, 1997). Clinical observation included closed eyes, wet mouths and noses, loss of coordination, nasal irritation, salivation, wet fur, tremors, labored breathing, and convulsions. Gross necropsy revealed no remarkable pathology.

Justification for classification or non-classification

TEA represents an acute hazard if administered to rats orally, dermal or by inhalation.

Due to the oral LD50 value of 730 mg/kg bw, severe skin damage and systemic toxic effects in treated animals (LD50 of 580 mg/kg bw), and LC50 of 1748 ppm (1 -hour LC50 of 3496 ppm is divided by a factor of 2) classification is warranted according to the criteria of EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008:

According to GHS:

Acute toxicity - oral: Cat.4;

Acute toxicity - dermal: Cat.3;

Acute toxicity - inhalation: Cat 3.

According to DSD:

T, R22/23 Toxic; Toxic by inhalation and in contact with skin