Extracts (petroleum), heavy paraffinic distillates, solvent-deasphalted

Endpoint summary

Description of key information

Read across from DAEs was used for TDAEs (IP 346 ≥ 3 wt%), and a key skin irritation study was identified (similar to OECD 404).  Although the skin irritation is valid in its methodology, it differs from the current OECD guidelines in that animals were exposed under occluded conditions for 24 hours instead of semi-occluded conditions for 4 hours.  Considering the conditions of the test, results must be interpreted carefully for the purposes of classification and labelling.  The mean scores for erythema and oedema after exposure to distillate aromatic extracts have been assessed against the deviations, and provided the test would be conducted under standard conditions, slight irritation might be expected but insufficient to classify.  Read across from OLBOs (IP 346 < 3%) was used for TDAEs (IP < 3%), and one key skin irritation study was identified (non-guideline).  In this study, sufficiently refined other lubricant base oils (IP 346 < 3%) were not observed to be skin irritants when applied dermally to the skin of rabbits for 24-hours (mean erythema and oedema scores were 0.17 and 0, respectively at 72 hours).
Read-across eye irritation studies (OECD 405) irritation studies were identified from both DAEs and OLBOs (IP 346 < 3%).  All studies were not irritating to the eyes of rabbits.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Treated distillate aromatic extracts (TDAEs) are a further processing of distillate aromatic extracts (DAEs) 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 DAEs 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. 

Skin Irritation

Multiple studies were available to assess the skin irritation potential of DAEs and OLBOs (IP 346 < 3%). 

TDAEs (IP 346 ≥ 3 wt%)

A key read-across skin irritation study was identified. In this study, white rabbits (6 male) were dermally exposed to 0.5 mL of light paraffinic distillate solvent extract for 24 hours to both an intact skin site and abraded skin site (API, 1986a). Animals then were observed for 14 days. Irritation was scored by the method of Draize (1959). The mean (24 and 72 hour, intact skin) erythema and oedema scores were 2.45 and 2.5, respectively.

Although this test is valid in its methodology, it differs from the current OECD guidelines in that animals were exposed under occluded conditions for 24 hours instead of semi-occluded conditions for 4 hours. Considering the conditions of the test, results must be interpreted carefully for the purposes of classification and labelling. The mean scores for erythema and oedema have been assessed against the deviations, and provided the test would be conducted under standard conditions, slight irritation might be expected but insufficient to classify. 

It is concluded therefore that DAEs are not skin irritants, but may cause defatting and skin dryness. Hence EUH066 is appropriate for all DAEs. This is also supported by repeated dose studies.

Additional data support that DAEs are not skin irritants (ARCO, 1973d; ARCO, 1982d; ARCO, 1984 g,h,i; ARCO, 1985d; Food and Drug Research Laboratories, 1974d). This information is presented in the dossier.

TDAEs (IP 346 < 3 wt%)

A key primary dermal irritation study (API, 1982a) was identified to evaluate the skin irritation potential of sufficiently refined other lubricant base oils (IP 346 < 3%). In this primary dermal irritation study, 6 New Zealand White rabbits (3 male/3 female) were dermally administered 0.5 mL solvent dewaxed light paraffinic oil (CAS No. 64742-56-9) under occlusive wrap for 24-hours. After the exposure period, the bandages were removed and test sites were wiped with gauze sponges. The animals were observed thereafter and dermal irritation was scored using the method of Draize at 24 hours, 72 hours and on Day 7 post-exposure.

Oedema was not apparent in male or female rabbits at any observation point. Very slight erythema (1) was evident in all male and female rabbits at the 24 hour observation point. Very slight erythema (1) was observed in only 1 male rabbit by the 72 hour observation point and no irritation was visible in any test animal by the end of the 7-day observation period. No differences in irritation were observed between intact and abraded skin sites. Solvent dewaxed light paraffinic oil was not considered to be irritating to the skin of rabbits.

Supporting read-across data from studies conducted in rabbits (API, 1982b; 1982c; 1982d; 1982e; 1982f; 1982g; 1986b; UBTL, 1984a; 1984b; 1984c; 1984d; 1984e; Trimmer et al. 1989) and humans (ExxonMobil Biomedical Sciences, Inc., 1988d) demonstrate that sufficiently refined other lubricant base oils (IP 346 < 3%) are either only weakly irritating or not irritating to the skin of rabbits and humans.

Eye Irritation

Multiple studies were available to assess the eye irritation potential of DAEs and OLBOs (IP 346 < 3%). 

TDAEs (IP 346 ≥ 3 wt%)

One key read-across eye irritation study was identified (API, 1986a). In this study, 0.1 mL of undiluted light paraffinic distillate solvent extract was instilled into the conjunctival sac of one eye of 9 white rabbits. Group I animal eyes remained unwashed, while Group II animal eyes were flushed with water for 1 minute, 20 to 30 seconds after instillation. Animals then were observed for 7 days. Irritation was scored by the method of Draize (1959).

The mean cornea, iris, conjunctivae scores (24 to 72 hours) were 0.0, 0.0, and 0.44, respectively. In this study, light paraffinic distillate solvent extract is not an eye irritant. Untreated DAEs are classified as not irritating to the eye according to EU criteria. 

Additional data support that DAEs are not eye irritants (ARCO, 1973b; ARCO, 1982b; ARCO, 1984j, k, l, m; and Food and Drug Research Laboratories, 1974c). This information is presented in the dossier.

TDAEs (IP 346 < 3 wt%)

In a primary eye irritation study (API, 1982a), 0.1 millilitres of solvent dewaxed light paraffinic oil (CAS 64742-56-9, IP 346 < 3%) was instilled in the eyes of New Zealand White rabbits with and without a 30-second rinse. A single male rabbit in the no-rinse group showed conjunctival chemosis at 48 hours which resolved by 72 hours. No rabbits in the washed group exhibited irritation; therefore, dewaxed light paraffinic oil is not considered an eye irritant.

Supporting data from studies conducted in rabbits (API, 1982b; 1982c; 1982d; 1982e; 1982f; 1982g; 1986b;UBTL, 1984f; 1984g; 1984h; 1984i) demonstrate that sufficiently refined other lubricant base oils (IP 346 < 3%) are not ocular irritants.

The following information is taken into account for any hazard / risk assessment:

Read across from DAEs was used TDAEs (IP 346 ≥ 3 wt%), and a key skin irritation study was identified (similar to OECD 404). Although the skin irritation is valid in its methodology, it differs from the current OECD guidelines in that animals were exposed under occluded conditions for 24 hours instead of semi-occluded conditions for 4 hours. Considering the conditions of the test, results must be interpreted carefully for the purposes of classification and labelling. The mean scores for erythema and oedema after exposure to distillate aromatic extracts have been assessed against the deviations, and provided the test would be conducted under standard conditions, slight irritation might be expected but insufficient to classify. Read across from OLBOs (IP 346 < 3%) was used for TDAEs (IP < 3%), and one key skin irritation study was identified (non-guideline). In this study, sufficiently refined other lubricant base oils (IP 346 < 3%) were not observed to be skin irritants when applied dermally to the skin of rabbits for 24-hours (mean erythema and oedema scores were 0.17 and 0, respectively at 72 hours).

Read-across eye irritation studies (OECD 405) irritation studies were identified from both DAEs and OLBOs (IP 346 < 3%). All studies were not irritating to the eyes of rabbits.

Justification for classification or non-classification

Based on read-across skin irritation scores after 24 hours exposure from DAEs, TDAEs (IP 346 ≥ 3%) are not classified as irritating to skin. Based on a read-across skin irritation study from OLBOs (IP 346 < 3%), TDAEs (IP 346 < 3%) are not classified under the EU CLP Regulation (EC No. 1272/2008).  TDAEs (both IP 346 ≥ 3% and IP < 3%) do not meet the criteria for classification as eye irritants according to the EU CLP Regulation (EC No. 1272/2008) based on read across information.