1,2,3,5,6,7-hexahydro-1,1,2,3,3-pentamethyl-4H-inden-4-one

Endpoint summary

Description of key information

- Acute oral toxicity: LD50 is 2685 mg/kg bw (female) (method similar to OECD TG 401)
- Acute inhalation toxicity: LD50 is 17400 mg/m3 (route-to-route extrapolation from acute oral toxicity study)
- Acute dermal toxicity: LD50 is 2685 mg/kg bw (route-to-route extrapolation from acute oral toxicity study)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 685 mg/kg bw

Quality of whole database:

This study is adequate for covering this endpoint.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

17 400 mg/m³ air

Quality of whole database:

This assessment is considered to be sufficient adequate for covering this endpoint.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 685 mg/kg bw

Quality of whole database:

This assessment is considered to be adequate for covering this endpoint.

Additional information

Acute oral toxicity

In an acute oral toxicity study (OECD TG 401), four groups of ten rats (five males and five females) were administered the test substance (test article 85-206-02) at dose levels of 2000, 3200, 4000 and 5000 mg/kg bw. The rats showed decreased activity, diarrhea, salivation, lacrimation, ptosis, poor grooming, piloerection, decreased or increased muscle tone, abnormal stance, abnormal gait, dyspnea, tremors, convulsions, wet pelage (ventral surface), red discoloration, writhing and prostration. 1 of 10 rats died at 2000 mg/kg, 5 of 10 died at 3200 mg/kg, 9 of 10 died at 4000 mg/kg and 10 of 10 died at 5000 mg/kg. Necropsy of the animals dying on the study revealed hemorrhagic lungs, discolored and fluid-filled intestines, distended stomachs and multiple lesions in the stomachs. The acute oral LD50 for the test substance in male and female rats was determined to be 2901 mg/kg bw with 95% CI of 2325 - 3619 mg/kg bw. The calculated LD50 for males was 3380 mg/kg bw (95% CI: 2907 - 3930 mg/kg bw). The calculated oral LD50 for females was 2685 mg/kg bw (95% CI: 2043 - 3529 mg/kg bw).

Acute dermal toxicity

With respect to the acute toxicity via the dermal route, the study is scientifically unjustified because the acute oral toxicity is above 2000 mg/kg bw. Based on the toxicokinetic data the dermal availability is not expected to exceed the oral availability. Therefore, the LD50 via the dermal route can be estimated to be similar to the oral LD50, because 50% absorption is assumed via both routes, resulting in an LD50 of 2685 mg/kg bw.

Acute inhalation toxicity

An acute inhalation toxicity study is not needed for substances with high viscosity (the substance has a viscosity of 31.7 mP.s) and acute oral and dermal toxicity values are available. For inhalation, an LD50 of 2900 mg/kg bw can be roughly converted into 174000 mg/per person by multiplying it with a person’s weight: (60 kg 2900 x 60=174000). An inhalation volume for one person during 4 h (standard exposure time in the OECD TG for acute inhalation is 5m3 (assuming 10m3/8h for workers). This means that an LC50 concentration in 1 m3 and 4 hours exposure is 34800 mg/m3 (174000mg/5m3). Taking into account that during that the absorption during the inhalation route is twice the oral route the LC50 and therefore the LC50 for inhalation could be 17400 mg/m3. The maximum saturates vapour pressure for Cashmeran is 84.7 mg/m3 (1 Pa (Vap Pr. Cashmeran) x 206 (MW) / 8.3 (R, gas constant) x 293 (°K)). This means that Cashmeran cannot reach a concentration higher than 84.7 mg/m3. 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

According to the criteria outlined in EU CLP (EC no 1272/2008 and its amendments), the substance does not have to be classified as acute toxic by the oral, dermal and inhalation route.

The substance has an LD50 of 2685 mg/kg bw (between 2000-5000 mg/kg bw) and therefore it needs to have hazard phrase H303: May be harmful if swallowed under GHS.