Docosyl stearate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

Summary of available data used for the endpoint assessment of the target substance

Adequacy of study:

key study

Justification for type of information:

Please refer to the analogue justification attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

based on Water Accomodated Fraction

Basis for effect:

mortality (fish)

Remarks on result:

other: Source, CAS 36078-10-1 Dako, 2013, D.rerio, 96h

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

based on water accomodated fraction

Basis for effect:

mortality (fish)

Remarks on result:

other: Source, CAS 93803-87-3, Croda, 1998, C. carpio, 96h

Conclusions:

The key values for the short-term toxicity of the target substance is an EL50 (96 h) > 100 mg/L (nominal, WAF) based on the experimental studies for two structrually and chemically closely related source substances (OECD 203, D. rerio and C. carpio).

Description of key information

LL50 (96h) >100 mg/L (D. rerio and C.carpio, OECD 203, nominal, read-across)

Additional information

Since no studies investigating the short-term toxicity of Docosyl stearate (CAS 22413-03-2) to fish are available, in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5 a read-across to the structurally related source substances dodecyl oleate (CAS 36078-10-1) and 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) were conducted. The source substances are considered to be representative to evaluate the short-term toxicity of Docosyl stearate (CAS 21443-03-2) to fish. The target substance is an ester of stearic acid (C18) and docosanol (C22). The source substance Dodecyl oleate (CAS 36078-10-1) is an ester of similar fatty acid (C18:1) and a shorter chain alcohol (C12). 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) is described by isostearic acid (C18) and a branched alcohol (C20) with comparable chain length to the target substance. The source substances are therefore considered suitable representatives for the assessment of the short-term toxicity of the target substance to fish. This read-across is justified in detail within the analogue justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment.

The study with the read-across substance dodecyl oleate (CAS 36078-10-1) investigated the toxicity to fish. The study was performed according to OECD 203 under GLP conditions with the zebrafish Danio rerio. A limit test with a Water Accommodated Fraction (WAF) of 100 mg/L (nominal) did not result in any mortality after 96 h. Thus, a LL50 (96 h) of > 100 mg/L was derived based on the nominal loading rate. The chemical analysis resulted in concentrations below the analytical detection limit of 0.005 mg/L reflecting the very low water solubility of the test item.

The study with the read-across substance of 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was performed according to OECD 203 with the carp Cyprinus carpio. Water Accommodated Fractions (WAF) of nominal 10 and 100 mg/L were prepared and tested under static conditions. A chemical analysis of the test substance concentrations in the test vessels was not possible since no applicable method could be established due to the very low water solubility to detect test concentrations. No mortality was observed after 96 h and therefore a LL50 of > 100 mg/L (nominal) was derived.

Based on the available result from two structurally related source substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that docosyl stearate (CAS 22413-03-2) will not exhibit short-term effects to fish up to the limit of water solubility.