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

Endpoint summary

Description of key information

Key read-across acute oral, dermal, and inhalation toxicity studies were identified from untreated distillate aromatic extracts and other lubricant base oils (OLBO; IP 346 < 3%)  Results for key studies are as follows:

• The oral LD50 was > 5000 mg/kg bw in male and female rats for UDAEs in an acute oral study (similar to OECD 420).

• The oral LD50 was > 5000 mg/kg bw in male and female rats for OLBO (IP 346 < 3%) in an acute oral study (OECD 401).

• The dermal LD50 was > 2000 mg/kg/bw in male and female rabbits for UDAEs in an acute dermal study (similar to OECD 402).

• The dermal LD50 was > 5000 mg/kg/bw in male and female rabbits for OLBO (IP 346 < 3%)  in an acute dermal study (OECD 402).

• The inhalation LC50 was > 5 mg/L in male and female rats for UDAEs in an acute inhalation study (OECD 403).

• The inhalation LC50 was > 5.53 mg/L in male and female rats for OLBO (IP 346 < 3%) in an acute inhalation study (OECD 403).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 000 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

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.

 

Acute oral toxicity:

In a key read-across acute oral toxicity study from UDAE, male and female rats were administered a single oral dose of undiluted untreated distillate aromatic extract (CAS No. 64742-04-7) at a dose of 5000 mg/kg bw (ARCO, 1985a). There were no deaths during the 14-day observation period. No treatment-related lesions were observed at gross necropsy. The LD₅₀ of the test material was determined to be > 5000 mg/kg body weight.

Additional data support that UDAEs are not acute oral toxicants (ARCO, 1973a; ARCO, 1982a; ARCO, 1983a, 1983b, 1983c). This information is presented in the dossier.

 

Many studies were available to assess the acute oral toxicity of other lubricant base oils (OLBOs). In a key read across acute oral toxicity test (API, 1982a), API 78 -10 (CAS No. 64742 -65 -0) was administered orally via gavage to Sprague-Dawley rats (5/sex) at 5000 mg/kg. No mortality was observed in any male or female rat. Besides two rats appearing scruffy on day 1, no other signs of clinical toxicity were observed through the study period. Two female rats exhibited below average body weight gain over the study period. Body weight and weight gain of all other animals appeared normal through the study period. No gross lesions were observed in either male of female rats orally administered API 78-10. Based on the lack of systemic adverse effects observed, the acute oral LD₅₀for API 78-10 was determined to be >5000 mg/kg.

Supporting data from studies (API 1982b; 1982c; 1982d; UBTL, 1983a; 1983b; 1983c) conducted in rats demonstrate that other lubricant base oils (IP 346 < 3%) have acute LD₅₀s >5000 mg/kg body weight.

Acute Inhalation Toxicity:

In a key read-across acute inhalation toxicity study, groups of young adult Sprague Dawley rats (5/sex) were exposed by inhalation route to untreated distillate aromatic extract for 4 hours to whole body at a concentrations of 5.0 mg/L (ARCO, 1983d). Animals then were observed for 14 days. All animals were lethargic during the last 2 hours of exposure. From hour 2 of treatment until the first hour post-exposure, animals kept their eyes partially closed and were lacrimating. One rat displayed red nasal discharge following exposure and red ocular discharge. Another rat exhibited yellow eye discharge during the fourth hour post-exposure and red eye discharge the morning following discharge until the end of the third day post-treatment. These findings are considered related to treatment. Three rats of each sex showed pallor and/or swelling of the kidneys. These findings may be related to treatment. The acute aerosol LC₅₀ of untreated distillate aromatic extract is greater than 5.0 mg/L of air. Additional data support that UDAEs are not acute inhalation toxicants (ARCO, 1983e). This information is presented in the dossier.

Two studies were available to assess the acute inhalation toxicity of other lubricant base oils. The Exxon Biomedical Sciences, Inc. (1988a) study analyzed the toxic inhalation effects of a solvent extracted paraffinic oil, a sufficiently refined (IP 346 < 3%) OLBO. In this study, five male and five female young adult Sprague- Dawley rats were exposed by inhalation route to MRD-87 -102 (a sufficiently refined lubricant base oil; IP 346 <3%) for four hours (whole body) at a concentration of 5.53 mg/L. Animals then were observed for 14 days. No mortality in either the control or exposed group was reported. There were no statistically significant differences in mean body weight between groups. Based on the results of the study, the four hour LC₅₀ for MRD-87-102 (CAS # 64741-88-4) in rats by inhalation would appear to be greater than 5.53 mg/L. Additional data support that OLBOs are not acute inhalation toxicants (EMBSI, 1988b). This information is presented in the dossier.

Acute Dermal Toxicity:

In a key read across dermal toxicity study (ARCO, 1985b), undiluted test material (untreated distillate aromatic extract; CAS No. 64742-04-7) was applied to the clipped abraded skin of New Zealand White rabbits (5/sex) at a dose of 2 g/Kg The application site was covered with a gauze  pad, held in place with a strip of hypoallergenic tape, after which a plastic barrier was applied around the back and abdomen by an elastic wrap. 24 hours after application, the wrap was removed and the skin was wiped to remove any residual test material.

The animals were observed for clinical signs of toxicity hourly for the first 5 hours after dosing and then twice daily for 14 days.  At the end of the 14-day observation period all surviving animals were killed.  A gross necropsy was performed  on all animals whether dying during the study or  killed at the end of the study. There were no mortalities during the study. The dermal LD₅₀ was determined to be > 2000 mg/kg.

Additional data support that UDAEs are not acute dermal toxicants (ARCO, 1973b; ARCO, 1982b; ARCO, 1984a, 1984b, 1984c). This information is presented in the dossier.

 

Two studies were available to assess the acute dermal toxicity of other lubricant base oils. 

In a key read across acute dermal toxicity study (API, 1982a), groups of New Zealand white rabbits (2/male and 2/ female) were dermally exposed to lubricant base oil API 78 -10 (CAS No. 64742-65-0) for 24 hours at doses of 2000 or 5000 mg/kg bw.  Animals then were observed for 14 days.

After 14 days, all animals were killed and were subjected to a gross necropsy. There were no mortalities in any of the studies. The only clinical signs were skin irritation and the occurrence of soft stool in some animals, but this latter effect was transient. Skin irritation ranged from slight to severe for erythema and oedema; slight to marked for atonia, desquamation, and fissuring; and from slight to moderate for coriaceousness. The LD50s were greater than the doses that had been applied (i.e. >2000 or 5000 mg/kg).

Supporting data from studies (API 1982b; 1982c; 1982d) conducted in rabbits have also demonstrated that sufficiently refined other lubricant base oils (IP 346 < 3%) have dermal LD₅₀s of >5000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint

One of 13 available studies

Justification for selection of acute toxicity – inhalation endpoint

One of 4 available studies

Justification for selection of acute toxicity – dermal endpoint

One of 10 available studies

Justification for classification or non-classification

Based on read-across acute oral, dermal, and inhalation toxicity results from UDAEs, TDAEs (IP 346≥ 3 wt%) are not classified under the EU CLP Regulation (EC No. 1272/2008) as an acute toxicant. Additionally, based on the lack of adverse effects in read-across studies from OLBOs (IP 346 < 3%), TDAEs (IP 346< 3 wt%) are not classified under the EU CLP Regulation (EC No. 1272/2008) as acute toxicants.