Extracts (petroleum), solvent-refined heavy paraffinic distillate solvent

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Treated distillate aromatic extracts (TDAEs) are a further processing of untreated distillate aromatic extracts (UDAEs) in an attempt to reduce the amount of 3-7 ring PAC that is present. Since the treatment is mostly a selective reduction of PACs, the data from UDAEs can serve as read across where treatment was insufficient and a significant amount of PACs still remain (≥ 3 wt% DMSO extractables as measured by IP-346). Where treatment was sufficient to reduce the 3-7 ring PACs (<3 wt% DMSO extractables as measured by IP-346), the material is most similar to a lubricating base oil and it is this data that should be used for read across. 

TDAEs (IP 346 ≥ 3 wt%)

In a key read across study (API, 1986a), Light paraffinic UDAE (CAS number 64742-05-8) was tested on 10 Hartley guinea pigs for sensitization in a Buehler test. The procedure used was a closed patch test closely following the Buehler test method outlined in OECD Guideline 406. The animals were divided into six groups: test group (10), naïve control group (10), vehicle control (10), positive control (20) and finally a naïve positive control group (20). In the test group (8/10) animals displayed very slight erythema; the highest reaction did not exceed the highest reaction of the naïve control animals. No reaction was observed in 2/10 animals. Animals in the naïve control group (9/10), vehicle control group (3/10), displayed very slight erythema. No reaction was seen in the rest of animals in each group. The positive control group (20/20) showed slight to severe irritation. The reactions of all animals equalled or exceeded the highest reaction observed in the naïve positive control group (4/19). Since the challenge reactions of the test animals did not exceed the highest reactions of control animals in any of the two naïve groups, it was concluded that the test substance was not sensitizing.

TDAEs (IP 346 < 3 wt%)

In a key read across dermal sensitisation study (API, 1982e) 1.0 mL of test substance solvent dewaxed light paraffinic oil (CAS 64742-56-9, sufficiently refined, IP 346 < 3%) was applied to shaved skin of Hartley Albino guinea pigs under occlusive dressing once per week for three weeks with each exposure lasting 6 hours.  The challenge dose (1.0 mL test material) occurred two weeks after the last induction dose.  The challenge mean Draize scores were zero for erythema and oedema; therefore, solvent dewaxed light paraffinic oil was not considered to be a dermal sensitizer. 

In a study conducted with human volunteers (ExxonMobil Biomedical Sciences, Inc., 1988d), 112 human adults were dermally exposed to 0.2 mL of severely hydrotreated heavy naphthenic distillate (IP 346 < 3%) once a day, 4 days a week, for 13 exposures. A challenge phase was conducted where the participants were treated with 0.2 mL once a day, 4 days a week, for 1 week.  The test substance was considered not sensitising due to the small number of slight or mild irritation responses recorded. 

Supporting data from a study conducted in guinea pigs (Trimmer et al. 1989) and human volunteers (ExxonMobil Biomedical Sciences, Inc., 1988e; 1988f; 1988g) demonstrate that sufficiently refined other lubricant base oils (IP 346 < 3%) are not dermal sensitizers.

Migrated from Short description of key information:

Read across studies conducted with untreated distillate aromatic extracts (equivalent to OECD 406) or other lubricating base oils (IP 346 <3%; OECD 406) were found to be non-sensitising in Hartley Albino guinea pigs.

Justification for selection of skin sensitisation endpoint:

One of 3 available studies.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Respiratory sensitisation is not a standard information requirement.

Migrated from Short description of key information:

No data identified.

Justification for classification or non-classification

Based on read-across skin sensitisation data from UDAEs and OLBOs (IP 346 < 3%), TDAEs (both IP ≥ 3% or <3%) do not meet the criteria for classification as dermal sensitisers under the EU CLP Regulation (EC No. 1272/2008).