Docosane

PBT assessment

PBT assessment: overall result

Reference

Name:

docosane

Type of composition:

boundary composition of the substance

State / form:

solid: bulk

Reference substance:

docosane

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence (P) Assessment

A substance is not considered to be persistent if it can be demonstrated that it has potential to degrade (via photolysis, hydrolysis and/or biodegradation).

There are no data available for docosane. Data is available for GTL Base Oil Distillates and this data is used for read-across to docosane. The results from the ready biodegradability studies for GTL Base Oil Distillates ranged from 11-67% after 28 days. The main factors influencing the results include the guideline/method followed, the dosing method and the viscosity/composition of the test substance. In general, the biodegradability of the substances decrease as the viscosity (and hence carbon chain length/degree of branching) increases. In fact, the lowest viscosity substances almost meet the criteria for ready biodegradability. Overall GTL Base Oil Distillates is not considered to be readily biodegradable but is expected to be inherently biodegradable.

Therefore, docosane does not meet the Persistent (P) or very Persistent (vP) criteria.

Bioaccumulation (B) Assessment

Docosane has a log Kow of >6 and therefore can be classified as potentially bioaccumulative (B). It is not possible to draw a definitive conclusion on B for docosane due to a lack of further test data. However, because it is not classfied as P or vP, then no further testing is required.

 

Toxicity (T) Assessment

Human Health Hazards Assessment (T)

Carcinogenicity: There are no carcinogenicity data available for docosane. Data for the read-across substances C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) and C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) do not warrant classification for carcinogenicity under Dir 67/548/EEC or GHS/CLP.

Mutagenicity: There are no mutagenicity data available for docosane. Data for the read-across substances C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) and C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) classification for mutagenicity under Dir 67/548/EEC or GHS/CLP.

Reproductive Toxicity: There are no reproductive toxicity data available for docosane. Data for the read-across substances C18-C50 branched, cyclic and linear hydrocarbons – Distillates (CAS# 848301-69-9) and C8-C26 branched and linear hydrocarbons – Distillates (CAS# 848301-67-7) show there is no evidence that docosane causes reproductive or developmental toxicity and do not warrant classification under Dir 67/548/EEC or GHS/CLP.

 

Environmental Toxicity Assessment (T)

There are no data available on the acute ecotoxicity of docosane. Data is available for GTL Base Oil Distillates and this data is used for read across to docosane. The effect of GTL Base Oil Distillates on the respiration of activated sewage sludge micro-organisms gave a 3-Hour EC50 of greater than 1000 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/l.

GTL Base Oil Distillates were not identified as P or vP, but are potentially B, therefore no further assessment on T is needed. Using the read-across data for GTL Base Oil Distillates, docosane can be classified as not T.

 

Conclusion of PBT/vPvB assessment

There is no data available for docosane therefore this PBT/vPVB assessment has been made based on read-across data. This available data showed that docosane is not classified as P or vP, but is potentially B. The read-across data also do not meet the criteria for T. Therefore, docosane is not classified as PBT or vP or vB.