Mixed LOF

Endpoint summary

Key value for chemical safety assessment

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The hydroformylation process, involves the preparation of oxygenated organic compounds by the reaction of carbon monoxide and hydrogen (synthesis gas) with olefinic carbon compounds. Olefins which do not react, and paraffins produced by side reactions are the primary components of Mixed LOF.

The oxo reaction is performed under hydroformylation conditions in the presence of a carbonylation catalyst or catalyst precursor such as dicobaltoctacarbonyl, and results in the formation of a compound (e.g. an aldehyde) which has one more carbon atom in its molecular structure than the feedstock. Subsequent hydrogenation of the hydroformylation product leads to formation of the desired product alcohols. By virtue of the nature of the feedstock commonly available to industry, and indeed of the catalyst and reaction parameters employed, the hydroformylation reaction inevitably yields a range of products due to the numerous secondary reactions which take place.

Mixed LOF (Alkenes, C6-10, hydroformylation products, low-boiling; no CAS RN; EC number 931-285-8) is a byproduct from C7-C11 alcohol production. In the hydroformylation process olefins (alkenes) are catalytically reacted with carbon monoxide and hydrogen, resulting in a range of products including primary alcohols. Alcohols are separated from the reaction mixture by distillation, with the remaining LOF containing unreacted olefins (alkenes) and paraffins (alkanes), frequently of the branched [iso-] form. Compositional analysis indicates Mixed LOF is approximately a 50/50% mixture of olefins and paraffins with a boiling point range of 102 – 182 ºC.

While toxicity data are not available for LOF, based on composition and physical chemical characteristics it is appropriate to use data from naphtha petroleum streams with low levels of aromatic groups and carbon number ranges similar to C6-10. Naphtha streams are derived from the same original feedstock (crude petroleum) with a key process difference – feedstocks to the hydroformylation process (e.g., propylene, butene, and pentenes and combinations thereof) have very low to neglible aromatic material (e.g., benzene or toluene). Thus, use of naphtha streams can generally be considered a conservative read-across approach.

Light Catalytic Cracked Naphtha (LCCN; CAS No. 64741-55-5, consisting of hydrocarbons derived from a catalytic cracking process in the range of 4 to 11 carbons with a boiling range of approximately 65 to 230 degrees centigrade;) or Light Straight Run Naphtha (LSRN; CAS No. 64741-46-4, 64741-46-4, consisting predominantly of aliphatic [paraffinic and isoparaffinic] hydrocarbons in the range of 4 to 10 carbons and boiling between -20 to 180 degree centigrade) as read-across.

 

The human literature indicates that gasoline and naphtha blending stocks produce some dermal irritation but do not appear to be severe dermal irritants or corrosive agents. There is some evidence of eye irritation associated with gasoline vapor exposure at levels equal to and greater than 200 ppm, but the effects are not sufficient to warrant classification for eye irritation. Similarly, gasoline and naphtha blending stocks produced some dermal irritation but not corrosion when applied to rabbit skin. The level of irritation was enhanced when the test materials were applied under occluded patch. There was very little evidence of irritation when these materials were instilled into rabbit eyes.

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

To maintain alignment with the read-across substance Alkenes, C6 -10, hydroformylation products, low-boiling is classified as a skin irritation: R38 (Directive 67 -548 -EEC) and H315 (classification, labeling and packaging (CLP) regulation (EC) No 1272/2008).