3,7-dimethylnona-2,6-dienenitrile

Endpoint summary

Description of key information

Acute toxicity (oral): LD50>2000mgkg.
Acute toxicity (inhalation): No data; negligible exposure from use
Acute toxicity (dermal): LD50>2000mg/kg.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Acute oral toxicity; Acute dermal toxicity:

Weight of evidence from two studies on the registration substance, scored as Klimisch 4, and two additional studies on two structural analogues indicate that the substance is not harmful by oral exposure at concentrations greater than 2000mg/kg in the rat. The registration substance is therefore, not classified with regards to acute oral toxicity in accordance with Regulation (EC) No 1272/2008.

To address toxicological endpoints as part of the REACH registration of Lemonile (Target Substance) it is proposed to read-across to Citronellyl Nitrile and Hypo Lem (Source Substances).  

The use of read-across works within the spirit of REACH and the stated aim of the legislation to reduce animal testing where possible.

The Target Substance and Source Substances have been characterised in using the categories and databases present in the OECD [Q]SAR Toolbox. From the profiling in this table, it can be seen that the two substances share structural similarities and also ‘mechanistic action’ similarities which are both general and endpoint specific. For classification and labelling purposes this indicates that the structural analogue is harmless and would not, in itself, be classified in accordance with Regulation (EC) No 1272/2008 (CLP). The registration substance is considered to have similar properties and is therefore not classified in accordance with CLP.

Justification for selection of acute toxicity – oral endpoint
Weight of evidence from two studies on the registration substance, scored as Klimisch 4, and two additional studies on two structural analogues indicate that the substance is not harmful by oral exposure at concentrations greater than 2000mg/kg in the rat. The registration substance is therefore, not classified with regards to acute oral toxicity in accordance with Regulation (EC) No 1272/2008.

Justification for selection of acute toxicity – inhalation endpoint
The oral and dermal LD50 levels for lemonile have been determined and both demonstrate relatively harmless levels of acute toxicity LD50>2000 mg/kg bw and therefore do not require labelling under CLP. Testing by the inhalation route in accordance with column 2 of Annex VIII of 1907/2006/EC, is therefore considered to be inappropriate as exposure of humans via inhalation is minimal taking into account the vapour pressure of the substance (1.7 Pa at 20°C) and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size.

Justification for selection of acute toxicity – dermal endpoint
Weight of evidence from one study on the registration substance, scored as Klimisch 4, and two additional studies on two structural analogues indicate that the substance is not harmful by dermal exposure at concentrations greater than 2000mg/kg in the rat. The registration substance is therefore, not classified with regards to acute oral toxicity in accordance with Regulation (EC) No 1272/2008.

Justification for classification or non-classification

Weight of evidence from studies on the registration substance and on two structural analogues indicate that the substance is not harmful by oral and dermal exposure at concentrations greater than 2000mg/kg in the rat. The registration substance is therefore, not classified with regards to acute oral toxicity in accordance with Regulation (EC) No 1272/2008.

The Target Substance and Source Substances have been characterised in using the categories and databases present in the OECD [Q]SAR Toolbox. From the profiling in this table, it can be seen that the two substances share structural similarities and also ‘mechanistic action’ similarities which are both general and endpoint specific.For classification and labelling purposes this indicates that the structural analogue is harmless and would not, in itself, be classified in accordance with Regulation (EC) No 1272/2008 (CLP). The registration substance is considered to have similar properties to the structural analogues, therefore read across is justified.