Reaction mass of 2-ethylpropane-1,3-diol and 5-ethyl-1,3-dioxane-5-methanol and propylidynetrimethanol

Endpoint summary

Description of key information

The substance is of low toxicity.  An acute oral LD50 of >2000 mg/kg bw is reported.  The dermal LD50 of TMP is reported to be >10000 mg/kg bw.  A waiver is proposed for acute inhalation toxicity in accordance with Column 2 of Annex VIII of the REACH Regulation as acute toxicity data are available for the oral and dermal routes. Inhalation is not predicted to be a significant route of exposure based on the physicochemical properties of the substance.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

10 000 mg/kg bw

Additional information

Acute oral toxicity

The acute oral toxicity of Polyol TD was investigated in a GLP study conducted according to OECD Guideline 423 (Robinson, 2010). Polyol TD was administered to two groups of female Sprague-Dawley rats as a single dose of 2000 mg/kg bw. The animals were observed for signs of reaction to treatment for 15 days after administration. There were no unscheduled deaths during the observation period. Adverse signs were restricted to salivation at 5 min post dose, which was observed in all animals. Body weight gain was considered to be acceptable for rats of this age and strain and there were no macroscopic abnormalities recorded at necropsy. Under the conditions of the study the median lethal oral dose level (the LD₅₀) of Polyol TD in Sprague-Dawley rats was considered to exceed 2000 mg/kg bw.

Acute toxicity: dermal

The acute dermal toxicity of trimethylolpropane was determined in groups of 4 male albino rabbits (Elsea, 1956). The test material was moistened with distilled water and applied as a paste to the shaved, intact abdominal skin of the rabbits. Dose levels were 1.0, 2.15, 4.64 and 10.0 g/kg bw, the exposure period was 24 hours and the rabbits were observed for 7 days following exposure.

Dermal exposure resulted in a very mild degree of dermal irritation, that had subsided within 24 hours. There was no evidence of systemic toxicity, no mortalities occurred during the study, and there were no remarkable findings at gross necropsy. The acute dermal LD50 of trimethylolpropane is therefore greater than 10.0 g/kg bw in male rabbits.

No data are available for Polyol TD or CTF, however additional testing for acute dermal toxicity is not proposed. Based on the low acute oral toxicity of Polyol TD (with only minimal clinical signs seen at the limit dose of 2000 mg/kg bw), low acute dermal toxicity can also be predicted. Based on general theoretical considerations, dermal absorption of the individual components is likely to be less rapid and less extensive than oral absorption. Marked kinetic differences are unlikely, further indicating low dermal toxicity. This assumption is also confirmed by the very low acute dermal toxicity of the component TMP. It is therefore concluded that additional testing for acute dermal toxicity is not required scientifically and cannot be justified on grounds of animal welfare.

Acute inhalation toxicity

A waiver is proposed in accordance with Column 2 of Annex VIII of the REACH Regulation as acute toxicity data are available for the oral and dermal routes. Inhalation is not predicted to be a significant route of exposure based on the physicochemical properties of the substance.

Justification for classification or non-classification

The Reaction mass of 2-ethylpropane-1,3-diol(DMP) and 5-ethyl-1,3-dioxane-5-methanol(CTF) and propylidynetrimethanol(TMP) does not meet the criteria for classification according to Directive 67/548/EEC or Regulation 1272/2008/EC.