2,4,6-tribromophenol

Endpoint summary

Description of key information

Absortion: 2,4,6-Tribromophenol was rapidly absorbed from the gastro-intestinal tract [Clayton et al., 1981].

The absorption, distribution, and elimination of this substance were examined in male or female Eolzman’s albino rats after a single oral administration at doses from 4.04 to 5.34 mg/kg. This substance was rapidly absorbed in rats. The bulk of the radioactivity (77 %) was readily excreted via urine and 2 to 14 % were eliminated in the feces, within 48 hours. The pharmacokinetics of this substance in rats appeared to follow a one compartment open model system. The rate constant for elimination (Ke) was 0.3 and the half-life in the blood was 2.03 hours. Based on the results of this study, this substance should neither be persistent nor accumulative in mammalian systems [GLCC, 1977]

Key value for chemical safety assessment

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

50

Absorption rate - inhalation (%):

100

Additional information

2,4,6-Tribromophenol is rapidly absorbed from the gastro-intestinal tract and is rapidly excreted via urine and feces.

The acute oral LD50 in rats is 1,486 mg/kg bw. The acute inhalation LC50 in rats is greater than 50,000 mg/m3.

The acute dermal LD50 in rats is greater than 2,000 mg/kg bw.

This substance is considered to be non-irritating to the skin, but irritating to the eye. This substance is considered to be a sensitiser in guinea pigs.

A combined repeated dose toxicity study with the reproduction/developmental toxicity screening test [OECD TG 422] was conducted in SD rats administered by gavage at the doses of 0 (vehicle), 100, 300 and 1,000 mg/kg/day.

At 1,000 mg/kg/day, body weight gain suppression, and increase of absolute and relative liver weight were observed in both sexes and increases of total protein, albumin, A/G and ALP in blood were observed in male rats.

At 300 mg/kg/day, salivation was observed in both sexes and increase in blood creatinine was observed in male rats. The NOAEL for the repeat dose toxicity is considered to be 100 mg/kg/day in rats of both sexes.

In the above described combined repeated dose toxicity study with the reproduction/developmental toxicity screening test [OECD TG 422], SD (Crj: CD) rats received gavage doses of 0 (vehicle), 100, 300 and 1,000 mg/kg/day. No adverse effects were observed on estrous cycle, copulation index, fertility index and duration of gestation period, number of corpora lutea, and delivery findings as well as number of implants, number of total pups and live pups born, implantation index and delivery index in any of the substance-treated groups. Neonatal viability on day 4 of lactation and neonatal body weights on days 0 and 4 of lactation in the 1,000 mg/kg/day group were lower than those in the control group (about 50% for neonatal viability in the treated group). In maternal animals at the same dose, body weight was reduced by about 8 % and liver weight was increased by about 15 %. In conclusion, the oral NOAEL for reproduction/developmental toxicity is considered to be 300 mg/kg/day.