Diethylzinc

Endpoint summary

Description of key information

The endpoint is waived as the substance is corrosive, pyrophoric and water reactive.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vitro

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the substance is spontaneously flammable in air or in contact with water or moisture at room temperature

Interpretation of results:

other: Waiver

Conclusions:

Corrosive. Flammable in air at room temperature. Thus, exposure of mammalian species to zinc alkyls would notgenerate meaningful data, and no skin sensitization studies arerequired for this substance.

Executive summary:

Corrosive. Flammable in air at room temperature. Thus, exposure of mammalian species to zinc alkyls would notgenerate meaningful data, and no skin sensitization studies arerequired for this substance.

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Corrosive. Flammable in air at room temperature. Most of the chemistry of organozinc compounds can be explained in terms of the polarization of the zinc-carbon bond, the high energy of highest occupied molecular orbital (HOMO) and relatively low lying vacant 4s- and 4p-orbitals. These electronic properties render this class of compounds highly nucleophilic and easily oxidizable, which, for example, reflects in their high flammability in the air. Short chain zinc alkyls ignite spontaneously on contact with air and therefore are classified pyrophoric under UN transport classification. The flammability of Zn alkyls decreases on increasing bulkiness of the alkyl groups. Reactions of zinc alkyls with liquids are in some cases explosion like. Most prominent example is the violent reaction with water, which liberates for short chain alkyls highly flammable gases within seconds (alkyl groups with five carbon atoms and less).Low-lying vacant 4s- and 4p-orbitals are responsible for mild Lewis acidity of organozinc compounds. Driven by nucleophilic power of their alkyl groups organozinc compounds add to aldehydes, activated ketones and some other unsaturated electrophiles. High polarity of the Zn-C bond makes Zn alkyls rather good deprotonating agents.

Migrated from Short description of key information:

Corrosive. Flammable in air at room temperature. According to the Annex VII Standard Information Requirements forREACH, as step 2 of the assessment of skin sensitization endpoint, in vivo testing for skin sensitization is required. A specific rule foradaptation for an in vivo skin sensitization test states that the study does not need to be conducted if - the available information indicates that the substance should be classified for skin sensitizatin or corrosivity; or - the substance is a strong acid (pH < 2.0) or base(pH> 11.5); or - the substance is flammable in air at room temperature.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

The endpoint is waived as the substance is corrosive, pyrophoric and water reactive.

Justification for classification or non-classification

The substance is corrosive, pyrophoric and water reactive.