Formaldehyde, reaction products with phenol heptyl derivs. and 1,3,4-thiadiazolidine-2,5-dithione

Endpoint summary

Description of key information

Oral: The acute oral median lethal dose (LD50) of the test item in the Sprague Dawley strain rat was found to be greater than 2000 mg/kg bodyweight
Dermal: The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.
Inhalation: There will be no exposure to the test material via the inhalation route

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Oral

In the key study performed in accordance with the method described in Section 1500.3 of the Federal Hazardous Substances Act - 16 CFR, five male and five female animals were dosed with the test material as supplied at 2000 mg/kg. All ten animals survived for the 14 day observation period and all animals recovered from signs of ill-effects by day four.

In a supporting study performed to the same Guideline an additional five males and five females were dosed at 5000 mg/kg. Nine of the ten animals died within 24 hours whilst the tenth animal survived for the 2 week observation period.

The acute median lethal dose (LD₅₀) of the test material in the Sprague Dawley rat is greater than 2000 mg/kg but less than 5000 mg/kg.

Dermal

The study was performed in accordance with OECD Guidelines for the Testing of Chemicals No. 402 “Acute Dermal Toxicity” (adopted 24 February 1987) and Method B3 Acute Toxicity (Dermal) of Commission Regulation (EC) No. 440/2008

Initially, two animals (one male and one female) were given a single, 24 hour, semi‑occluded dermal application of the undiluted test item to intact skin at a dose level of 2000 mg/kg bodyweight. Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths. There were no signs of systemic toxicity. Very slight erythema was noted at the test sites of all animals. Other signs of skin irritation noted at the test sites of females were haemorrhage of the dermal capillaries, light brown discolouration of the epidermis, slight desquamation, glossy skin, scabbing and scab lifting to reveal glossy skin or dried blood. Haemorrhage of the dermal capillaries was also noted at the test site of one male.

Animals showed expected gains in bodyweight over the study period, except for one female which showed slight bodyweight loss during the first week but expected gain in bodyweight during the second week. 

No abnormalities were noted at necropsy.

The acute dermal median lethal dose (LD₅₀) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.

Inhalation

The substance is a liquid with a vapour pressure of 0.076 Pa at 25°C and is used primarily as a corrosion inhibitor by workers and consumers. It is expected that inhalation exposure from these uses will be low and that the most likely route of exposure for workers and consumers is the dermal route. Testing for acute toxicity via the inhalation route is, therefore, not required.

Justification for classification or non-classification

No LD50 up to and including the maximum dose level (2000 mg/kg bw) could be derived for acute oral or dermal exposure. The substance is not classified for acute toxicity.