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

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

TDAEs (IP 346 ≥ 3%) were evaluated using read-across information from distillate aromatic extracts.  Effects of DAEs on reproductive organs were examined in a 90-day dermal study in rats and a 90-day oral study.  Detailed results of these studies are presented in the Repeated dose toxicity section.  Histopathological changes in the reproductive organs or sperm morphology counts were not observed in the dermal study; however they were observed in the oral study.

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. 

TDAEs (IP 346 ≥ 3 wt%)

According to Mobil (1989b), implantation was not affected by treatment in a read-across DAE developmental toxicity study by dermal application in rats at doses of 0, 8, 30, 125 (gestation days 0–19) 500 mg/kg (gestation days 0–16), or 1000 mg/kg (gestation days 10-12). The number of dams with no viable offspring was increased at 125 and 500 mg/kg, but not at 1000 mg/kg for the shorter exposure duration.

 

TDAEs (IP 346 < 3 wt%)

In a key reproduction/developmental screening study (WIL Research Laboratories, 1995), a sufficiently refined other lubricant base oil (IP 346 < 3%) was administered by gavage at a dose of 1000 mg/kg (bw) to a group of 12 male and 12 female Sprague-Dawley rats. Rats designated F0 animals were dosed for a minimum of 14 days prior to mating. Dosing was continued after mating until a total dosing period of 30 days had elapsed for males and until day 4 of lactation for females (39 days). The animals were observed twice daily for appearance, behaviour, morbidity and mortality. Males and females were also observed during dosing and for one hour thereafter. Male F0 body weights were recorded weekly. Female F0 body weights were also recorded weekly until evidence of mating was observed and then on gestation days 0, 7, 14 and 20 and on lactation days 1 and 4. Food consumption was also recorded for F0 (both sexes). Animals were paired on a 1:1 basis. Positive evidence of mating was confirmed either by the presence of sperm in a vaginal smear or a vaginal plug. The day when evidence of mating was identified was termed Day 0 of gestation.

 

The following fertility indices were calculated: Female mating index; Male mating index; Female fertility index; and Male fertility index. All females were allowed to deliver their young naturally and rear them to post-natal day 4. Females were observed twice daily during the period of expected parturition for initiation and completion of parturition and for signs of dystocia. After parturition, litters were sexed and examined for evidence of gross malformations, numbers of stillborn and live pups. Litters were examined daily, and each pup received a detailed physical examination on days 1 and 4 of lactation. All abnormalities were recorded. The live litter size and viability index were calculated. All surviving pups were necropsied on post-natal day 4. A complete gross examination was made on all animals at necropsy. Selected organs of parental animals were weighed, and a wide range of tissues were fixed for subsequent histopathological examination.

 

There were no clinical findings and growth rates and food consumption values were normal. Fertility indices and mating indices for males and females were both 100%. At necropsy, there were no consistent findings, and the animals were considered to be normal. Organ weights and histopathology were considered normal. The NOAEL for this study was ≥1000 mg/kg/day.

Short description of key information:
Impact on fertility for TDAEs (IP 346 ≥ 3%) is inferred using read-across information from distillate aromatic extracts developmental studies. . TDAEs (IP 346 < 3%) were evaluated using read-across data from other lubricating base oils (IP 346 < 3%). For DAEs, a developmental toxicity study (OECD 414) reported that implantation was not affected by dermal treatment of rats up to dose levels of 1000 mg/kg/day. A key read-across screening reproductive/developmental study (OECD 421) was conducted on other lubricant base oils (IP 346 < 3 wt%) with no reproductive effects were observed in Sprague-Dawley rats.

Effects on developmental toxicity

Description of key information

TDAEs (IP 346 ≥ 3%) were evaluated using read-across information from distillate aromatic extracts.  TDAEs (IP 346 < 3%) were evaluated using read-across data from other lubricating base oils (IP 346 < 3%). In a key read-across development study (OECD 414), exposure to heavy paraffinic distillate aromatic extract produced maternal, reproductive and foetal toxicity.  Maternal toxicity was exhibited as vaginal discharge (dose-related), body weight decrease, reduction in thymus weight and increase in liver weight (125 mg/kg/day and higher) and aberrant haematology and serum chemistry (125 and/or 500 mg/kg/day). Evidence of potential reproductive effects was shown by an increased number of dams with resorptions and intrauterine death.  DAE was developmentally toxic as indicated by increased resorptions and decreased foetal body weights. Furthermore, when exposures were increased to 1000 mg/kg/day and given only during gestation days 10 through 12, cleft palate and ossification delays were observed. Cleft palate was considered to indicate a potential teratogenic effect of DAE.  
DAEs were developmentally toxic as indicated by increased resorptions and decreased foetal body weights.  These results indicate that based on read-across to DAEs, TDAEs (IP 346≥ 3 wt%) are considered to have developmental effects.  
For lubricating base oils with an IP-346 less than 3%, one key developmental study (OECD 414) was identified.  The study was conducted dermally with Sprague-Dawley rats.  A maternal LOAEL was not reported but can be referenced to be 125 mg/kg/day based on skin irritation.  A developmental/teratogenic NOAEL was not reported; however, it can be inferred that this value is 2000 mg/kg/day.  
Based on read-across data from other lubricant base oils (IP 346 < 3 wt%) and lack of effects on developmental endpoints, TDAEs (IP 346 < 3 wt%) are not considered to have developmental effects.

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. 

TDAEs (IP 346 ≥ 3 wt%)

In a read-across developmental study, heavy paraffinic distillate aromatic extract (CAS# 64742 -04 -7) was tested in a dermal study during gestation days 0 to 19 for developmental effects and maternal toxicity in the Sprague-Dawley rat (Mobil, 1989b). Nine groups of pregnant rats were divided in three groups: prenatal, postnatal and bioavailability groups. These groups are further described below. Bioavailability group procedures and results are described separately.

 

Prenatal groups: the undiluted test sample was applied without occlusion to the shaved skin of pregnant rats at doses of 8, 30, and 125 mg/kg/day on gestation days 0-19 (15/group). An additional group received the same treatment at 500 mg/kg/day on gestation days 0 through 16. Initially, administration of the test sample to the 500 mg/kg/day group was also scheduled for gestation days 0 through 19, however treatment was discontinued after gestation day 16 because a high incidence of resorption was suspected (as indicated by a red vaginal discharge observed among rats in this group). Another prenatal group received the same treatment at 1000 mg/kg/day only on gestation days 10 through 12, an interval at which the developing foetus is sensitive to teratogenic insult. A group of sham treated rats served as control. Prenatal groups were sacrificed on gestation day 20.

 

The postnatal group was exposed under the same conditions as the prenatal group. Postnatal animals (10/group) were dosed at 0 or 125 mg/kg/day on gestation days 0 through 19. Postnatal groups were allowed to deliver their offspring naturally. Pups were observed on post partum day 0 for external malformations and variations and then together with their dams, sacrificed on post partum day 4.

 

End points examined in adults included clinical signs (all groups except bioavailability group) body weight (all groups), food consumption (all groups except bioavailability group), haematology and serum chemistry (only prenatal groups), liver and thymus weights (all groups except bioavailability group), and uterine and net body weights (all groups except bioavailability group). Foetal toxicity examinations included: resorption incidences, anomalous development (gross, skeletal and visceral abnormalities) and body weight.

 

Results - Prenatal Group

Prenatal groups were sacrificed on gestation day 20. All mothers were necropsied and grossly examined. Uterus and ovaries were excised and examined grossly. Numbers of corporea lutea per ovary of each pregnant animal were counted. Ovaries of non-pregnant animals were grossly examined and then discarded. Number and location of implantations, early and late resorptions and live and dead foetuses were recorded.

 

Maternal toxicity: Red vaginal discharge was observed in a number of pregnant animals in all untreated DAE-exposed groups. Although authors mentioned this as being dose related, no statistics are provided.

 

In general animals exposed at 125 and 500 mg/kg consumed less food; at this dose level significant reduction in body weight gain, net body weight gain, and gravid uterine weight occurred throughout gestation. Body weight gain was also decreased at dose level of 1000 mg/kg/day. Of the haematology parameters evaluated, platelet and white blood cell counts were significantly affected in a dose related manner. Effects on 14 of 22 analyzed serum components were noted at the 125 or/and 500 mg/kg/day dose levels.

 

Thymus weights were significantly reduced and liver weights increased at doses in excess of 30 mg/kg/day. 

 

Reproductive effects: Implantation was not adversely affected by treatment. The number of dams with no viable offspring was increased at dose levels from 125 mg/kg/day. Litter size was significantly lower and resorptions were significantly increased compared to controls at 125 mg/kg/day and higher.

 

Foetal toxicity and development: At 30 mg/kg/day, although not statistically significant, a twofold increase over controls in the number of resorptions was observed, which the authors considered as of biological relevance. However, reanalysis of the data using the litter as the statistical unit (rather than individual resorptions) identifies30 mg/kg bw/day as the appropriate NOAEL for developmental toxicity. Treatment at 125 mg/kg/day and at higher doses resulted in decreased mean foetal body weights. A statistically significant increase in the incidence of incompletely ossified skull bones in foetuses exposed in utero to 125 mg/kg/day was observed. 

 

When the period of exposure was restricted to gestation days 10 through 12 and the dose increased to 1000 mg/kg, defects in costal cartilage development were significantly increased. Two of 114 foetuses evaluated were oedematous and had cleft palates. The cleft palate finding was considered by the authors to be biologically significant and evidence of a teratogenic effect, basis very low historical control incidences at theirs and other laboratories.

 

Results - Postnatal Group

In the postnatal group (10/group), three females were found to be not pregnant, five females resorbed their entire litters and one dam had only two pups, which she subsequently cannibalized. The postpartum analysis of the single viable litter of this group was not meaningful.

 

Results - Bioavailability Group

The bioavailability group included 3 females which were dosed with¹⁴C-carbazole- and³H benzo[a]-pyrene [BaP] - labelled Untreated DAE at 1000/kg/day on gestation days 10 through 12 and were treated under the same conditions as the previous two groups. Animals were housed in metabolic cages until sacrifice; urine and faeces were collected.

 

Bioavailability group animals were sacrificed on gestation day 13. Maternal tissues collected for radioactivity measurements were: blood, thymus, liver, small intestine, large intestine, kidneys, stomach and ovaries. Placentas, embryos, amniotic fluid and yolk sacs were pooled for each dam before analysis of radioactivity.

 

Bioavailability analyses revealed that dermal absorption of both radiolabelled substrates occurred.¹⁴C-carbazole was more extensively absorbed than³H-BaP over a 72-hour period (20% and 4% of the original dose respectively after three applications). After 72 hours, about 2% of¹⁴C-carbazole and³H-BaP (2.1% and 1.8% respectively) was found in the maternal tissues, primarily in blood, large and small intestines. By comparison, less than 0.01% of each surrogate was detected in the embryo, indicating that³H-benzo[a]-pyrene and¹⁴C carbazole do not selectively accumulate in the embryo under conditions of this study. 

 

The authors concluded that under study conditions heavy paraffinic distillate furfural extract produced maternal, reproductive and foetal toxicity. Maternal toxicity was exhibited as vaginal discharge (dose-related), body weight decrease, reduction in thymus weight and increase in liver weight (125 mg/kg/day and higher) and aberrant haematology and serum chemistry (125 and/or 500 mg/kg/day). Evidence of potential reproductive effects was shown by an increased number of dams with resorptions and intrauterine death. DAE was developmentally toxic as indicated by increased resorptions and decreased foetal body weights. Furthermore, when exposures were increased to 1000 mg/kg/day and given only during gestation days 10 through 12, cleft palate and ossification delays were observed. Cleft palate was considered to indicate a potential teratogenic effect of DAE.

 

Additional data support that DAE is a developmental toxicant (Feuston and Hamilton, 1996; Feuston and Mackerer, 1996). This information is presented in the dossier.

 

TDAEs (IP 346 < 3 wt%)

A key read-across developmental study on lubricating base oils with an IP-346 less than 3% (Mobil Environmental and Health Science Laboratory 1987, Klimisch score=1) was identified. In this study, 100 SUS solvent refined base oil was administered to female Sprague Dawley rats dermally. There were five dose groups. Groups 2 through 4 (10 dams/group in Groups 2 and 3; 15 dams/group in Group 4) were administered 125, 500, 2000 mg/kg/day using a 1 cc syringe (calibrated in 0.01 cc). Dams were clipped on the dorsal surface, and the test material was dispensed evenly over the test site. Animals were fitted with Elizabethan-style collars. The control group (Group 1; 15 dams/group) was clipped and collared in a similar fashion. For the control group, the dorsal skin of each rat was stroked with the tip of a 1 cc syringe, but no test material was applied. A fifth dose group (5 dams/group) was used, in which dams were applied the base oil on gestation day 0-17 at a dose level of 2000 mg/kg/day. A base oil fortified with [1-14C]octacosane was administered on gestation day 18.

Dermal application of the lubricant base oil to pregnant rats during gestation produced slight dermal irritation at all dose levels. At these dosages, the lubricant base oil produced erythema and flaking of the skin at the site of application in a dose-dependent manner. One animal in the 500 mg/kg/day dose group had dermal oedema.

 

There were no other signs of maternal toxicity. Serum components were not adversely affected by the test material. According to the Group 5 results, the test material metabolites were able to pass across the placenta, but did not bioaccumulate in the foetuses. Maternal LOAEL was 125 mg/kg/day based on skin irritation. There was no evidence of teratogenicity. There were no treatment-related changes observed during the external, skeletal, or visceral evaluations. Mean foetal weight and crown-rump lengths were comparable across all dose groups. Developmental/teratogenic NOAEL was 2000 mg/kg/day.

In accordance with REACH Annex XI, a decision on testing in a second species is deferred on the basis of animal welfare grounds [Article 13(4) of REACH recognising EC Directive 86/609/EEC] until the ongoing Concawe testing programmes on reprotoxicity are completed, which are expected to integrate the existing data with newly developed in-vitro high throughput toxicology data leading into a valid test system to assess the PNDT endpoint.

Toxicity to reproduction: other studies

Additional information

No two -generation reproductive toxicity data are available for TDAEs, or to serve as read-across from DAEs or other lubricant base oils. As TDAE(IP 346 ≥ 3%) are classified as reproductive toxicants, a two generational study is not required. For TDAE (IP 346 < 3%) a key screening reproductive/developmental toxicity study on OLBOs showed no effects on reproductive parameters. 

Justification for classification or non-classification

A key read-across developmental toxicity study was conducted on DAE and produced maternal, reproductive and foetal toxicity in rats when administered dermally at doses up to 125 mg/kg/day. The NOAEL for reproductive and developmental toxicity was 30 mg/kg/day. Based on the study results and read-across from DAEs, TDAEs(IP 346≥ 3 wt%) are classified as Reproductive Toxicants Category 2 (H361d) according to the EU CLP Regulation (EC No. 1272/2008).

A key read-across developmental study was conducted on other lubricating base oils with an IP-346 < 3 wt%, and resulted in a developmental/teratogenic NOAEL inferred to be 2000 mg/kg/day. Based on this NOAEL and the use of the data as read-across, TDAEs (IP 346< 3 wt%) are not classified as a developmental toxicant according to the EU CLP Regulation EC No. 1272/2008).