Reaction mass of 2-(3-ethylphenyl)oxirane and 2,2’-(1,3-phenylene)dioxirane and 2,2'-(1,4-phenylene)dioxirane

Endpoint summary

Description of key information

The acute oral and the acute dermal median lethal doses (LD50) of the test material in the female Wistar strain rat were estimated to be greater than 2000 mg/kg bodyweight and therefore the submission substance was considered to have no significant acute toxic risk if swallowed and did not meet the criteria for classification according to EU labelling regulations Commission Directive 2001/59/EC for classification and labelling of dangerous substances. The study to determine the toxicity by the inhalation route was not conducted as it was deemed inappropriate as exposure to humans via inhalation is unlikely to occur as the substance does not have a high vapour pressure, and will not be used in a manner likely to produce aerosols, particles or droplets of an inhalable size. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Additional information

Acute oral toxicity: The study was performed to assess the acute oral toxicity of the test material in the Wistar strain rat. The method was designed to meet the requirements of the OECD Guidelines for Testing of Chemicals No 420 “Acute Oral Toxicity - Fixed Dose Method” (adopted 17 December 2001) and the Method B1 bis Acute Toxicity (Oral) of Commission Regulation (EC) No. 440/2008. Following a sighting test at a dose level of 2000 mg/kg, an additional four fasted female animals were given a single oral dose of undiluted test material at a dose level of 2000 mg/kg bodyweight. At the end of the 14 -day observation period, animals were sacrificed and the LD50 was determined to be >2000 mg/kg.

Acute dermal toxicity: The study was performed to assess the acute dermal toxicity of the test material in the Wistar strain rat. The method was designed to meet the requirements of the OECD Guidelines for the Testing of Chemicals No. 402 “Acute Dermal Toxicity” (adopted 24 February 1987) and Method B3 Acute Toxicity (Dermal) of CommissionRegulation (EC) No. 440/2008. A group of ten animals (five males and five females) was given a single, 24-hour, semi-occluded dermal application of the undiluted test material to intact skin at a dose level of 2000 mg/kg bodyweight.

Signs of dermal irritation noted were well-defined erythema, slight to moderate oedema (on occasions extending ventrally below test site), blanching of the skin, hardened dark brown/black coloured scab, small superficial scattered scabs, scab cracking and scab lifting to reveal glossy skin or bleeding. Adverse reactions prevented accurate evaluation of erythema and oedema from Day 4 until the end of the study on Day 14. The reactions noted at Day 14 were considered to be indicative of dermal corrosion.

However, since both the acute oral and the acute dermal median lethal doses (LD50) of the test material in the female Wistar strain rat were each estimated to be greater than 2000 mg/kg bodyweight the submission substance was considered to have no significant acute toxic risk if swallowed or in contact wit the skin. The submission substance therefore, did not meet the criteria for classification according to EU labelling regulations Commission Directive 2001/59/EC for classification and labelling of dangerous substances.

The above studies have been ranked Reliability 1 according to the scoring system of Klimisch et al. This ranking was deemed appropriate because the study was conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies which do not affect the quality of relevant results.

The study to determine the toxicity by the inhalation route was not conducted as it was deemed inappropriate as exposure to humans via inhalation is unlikely to occur as the substance does not have a high vapour pressure, and will not be used in a manner likely to produce aerosols, particles or droplets of an inhalable size.

Justification for classification or non-classification

The acute oral and the acute dermal median lethal doses (LD50) of the test material in the female Wistar strain rat were each estimated to be greater than 2000 mg/kg bodyweight and therefore the submission substance was considered to have no significant acute toxic risk if swallowed or via skin contact. The submission substance therefore did not meet the criteria for classification as toxic or harmful by oral or dermal route exposure according to EU labelling regulations during the study.

The study to determine the toxicity by the inhalation route was not conducted as it was deemed inappropriate as exposure to humans via inhalation is unlikely to occur as the substance does not have a high vapour pressure, and will not be used in a manner likely to produce aerosols, particles or droplets of an inhalable size.