Registration Dossier

Administrative data

Description of key information

Acute oral toxicity: LD50 >5000 mg/kg bw (similar to OECD TG 401, limit test)

Acute dermal toxicity: LD50 >5000 mg/kg bw (similar to OECD TG 402, limit test)

Acute inhalation toxicity: LD50: >35000 mg/m3 (calculated using route to route extrapolation from the acute oral toxicity results)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
The acute oral toxicity is of sufficient quality and adequate for this dossier.

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
The information is based on a roughly route to route extrapolation and sufficiently adequate to address the endpoint for hazard, classification and labelling and risk characterisation.

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
The acute dermal toxicity is of sufficient quality and adequate for this dossier.

Additional information

Acute oral toxicity

The acute oral toxicity of Cyclaprop was determined in an acute oral toxicity study according to methods similar to OECD401 (limit test), in which ten male rats were dosed 5000 mg/kg bw test material. All animals survived, resulting in a LD50 > 5000 mg/kg bw. The most prevalent toxic signs were lethargy, piloerection and chromorhinorrhea. Internal organs of all animals, necropsied on day 14, were normal upon superficial examination.

Acute dermal toxicity

In an acute dermal toxicity test, which was performed according to methods similar to OECD402 (limit test), 10 New Zealand White rabbits were exposed to 5000 mg/kg bw Cyclaprop under gauze patches and secured with adhesive tape. One death occurred, resulting in a LD50 > 5000 mg/kg bw. Most animals were generally healthy throughout the test period. Skin reactions (scored according to Draize) were non-existent to slight (one surviving animal with scaly skin) and body weight changes were within expected limits. All animal were normal upon necropsy, only one animal, dead on day 14, had liver nodules and scaly skin.

Acute inhalation toxicity

Acute inhalation toxicity is not anticipated because when the oral LD50 values are compared with the Saturated Vapour Concentration (SVC) of the substance, the result is that the inhalation LD50 value exceeds the SVC and thus the inhalation LC50 cannot be reached. This is calculated as follows: Cyclaprop has an oral LD50 of >5000 mg/kg bw, which can be converted to an inhalation LD50 using the equation: “Incorporated dose = concentration x respiratory volume x exposure time”: 1 mg/kg bw = 0.0052 mg/l/4h (ECHA guidance on CLP, 2017). In addition, for conservative reasons the inhalation absorption is set at 100% and oral at 50%. For Cyclaprop the LC 50 would be > 13000 mg/m3. Its SVC at ca. 20°C is 57 mg/m3. This SVCvalue can be calculated using vapour pressure and molecular weight (MW 206*VP (Pa) 0.67*1000 / 8.3 (gas constant)*293°K (20°C). In conclusion: with a maximum SVC of 57 mg/m3 the inhalation LC50 of > 13000 cannot be reached. Therefore, an LC50 for inhalation cannot be reached and no classification and labelling is needed for the acute inhalation route.

Justification for classification or non-classification

Cyclaprop does not need to be classified for acute oral, dermal and inhalation toxicity based on the information above and in accordance with EU CLP (EC 1272/2008 and its amendments).