Mixed LOF

Endpoint summary

Justification for classification or non-classification

The hydroformylation process, which in general terms is a process involving the preparation of oxygenated organic compounds by the reaction of carbon monoxide and hydrogen (synthesis gas) with carbon compounds containing olefinic unsaturation, and is particularly concerned with the treatment and recycling of by products of the primary oxo-reaction.

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 primary product leads to higher 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.

 

The Light Oxo Fraction (LOF, Alkenes, C6-10, hydroformylation products, low-boiling) is a by-product from C6-C8 alcohol formation. In the hydroformylation process branched olefins (isoalkenes) 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). Compositional analysis indicates 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) 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. 

 

Components present in petroleum naphthas such as unleaded gasoline vapor condensate and vapor recovery unit appear similar to those present in Alkenes, C6-10, hydroformylation products, low-boiling. Results from testing of these analogues indicate classification as a reproductive or developmental toxin is not warrranted according to the general classification and labeling requirements for dangerous substances and preparations (Directive 67-548-EEC) or the classification, labeling and packaging (CLP) regulation (EC) No 1272/2008.