Registration Dossier

Administrative data

Description of key information

No repeat-dose toxicity studies were located for oral toxicity of VGOs/HGOs/Distillate fuels.

However, supporting information is available, with two studies conducted on petroleum substances in other categories; a sub-chronic study on a Kerosine (CAS 8008-20-6) and a chronic study on a Highly Refined Base Oil (CAS 8042-47-5). These do not contain significant amounts of the PAH constituents considered to be the drivers of toxicological hazard for VHGO, but have other constituents in common. They help to demonstrate that no significant toxicological hazard is expected from other aliphatic (paraffinic and naphthenic) and aromatic (mono- and di- aromatic) constituents.

 

In addition, one oral sub-chronic study is proposed on a VHGO substance containing high levels of PAH constituents.

 

For sub-chronic inhalation toxicity of VGOs/HGOs/Distillate fuels, a conservative sub-chronic NOAEC of 750 mg/m3 was determined for local effects on the lung (increased relative wet weight in the absence of histopathological change). A NOAEC of >1710 mg/m3 was established for systemic effects, based on no significant findings at this level (OECD 413).

 

In a subacute dermal repeated-dose toxicity test, the NOEL level based on dermal irritation was 0.0001 mL/kg and a NOEL of 0.5 mL/kg was calculated for systemic toxicity (OECD 410). For subchronic dermal toxicity, a NOAEL of 30 mg/kg body weight/day appears appropriate for VGOs/HGOs/Distillate fuels based on changes in haematological parameters (decreased RBC, haemoglobin, HCT), clinical chemistry values (increased urea nitrogen and cholesterol) parameters and organ weight effects (increased liver weight, decreased thymus weight). The NOAEL for local effects is 125 mg/kg body weight/d, based on histopathological changes present at the application site (OECD 411).

In addition, a recent study to OECD 411 and GLP was conducted on a member of the VHGO category. This showed low systemic toxicity (NOAEL 600 mg/kg/day), with higher doses not possible due to excessive local irritation. This study was conducted on a substance in the category low in PAH content (the constituent expected to drive toxicological hazard).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
1 710 mg/m³
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEC
880 mg/m³
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
NOAEL
30 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
One of 17 repeat dose dermal studies

Additional information

No repeat-dose toxicity studies were located for oral toxicity.

However, supporting information is available, with two studies conducted on petroleum substances in other categories; a sub-chronic study on a Kerosine (CAS 8008-20-6) and a chronic study on a Highly Refined Base Oil (CAS 8042-47-5). These do not contain significant amounts of the PAH constituents considered to be the drivers of toxicological hazard for VHGO, but have other constituents in common. They help to demonstrate that no significant toxicological hazard is expected from other aliphatic (paraffinic and naphthenic) and aromatic (mono- and di- aromatic) constituents.

 

In addition, one oral sub-chronic study is proposed on a VHGO substance containing high levels of PAH constituents.

 

Inhalation Toxicity

In a 90-day sub-chronic inhalation toxicity study on diesel fuel, groups of male and female Sprague-Dawley rats were exposed whole body to 250, 750 or 1500 mg/m3aerosol (MMAD 0.43-0.75 microns) 4 hour per day, two days per week for 13 weeks (total of 26 exposures) (analytical concentrations:0.35, 0.88, and 1.71 mg/L). (Klimisch score = 2), Lock et al., 1984). The study also included a sham (chamber) control group and an untreated (animal room) control group, with animals in all groups aged 18-21 weeks at the start of the study. Body weight (all animals) and food consumption (6/sex/dose level) were recorded weekly. Breathing frequency was measured using a barometric method (groups of 12 rats/sex/dose level, temporarily housed in sealed chambers) prior to the first exposure (baseline), before the 14thand 26thexposures (i.e., study weeks 7 and 13), and after one or two months recovery. Startle reflex (assessed by measuring reaction time, peak time and peak height following exposure to five 10 msec pulses of 110 dB noise) was quantified in males only (8/dose) immediately after the first, 14thand 26thexposures to evaluate acute/short term effects. It was evaluated in both sexes (8/sex/dose) prior to the 14thand 26thexposures and after one and two months recovery to assess chronic/cumulative changes. The type and number of free cells present in pulmonary lavage fluid and serum chemistry (alkaline phosphatase, aspartate aminotransferase, cholesterol, triglyceride, uric acid, urea nitrogen, glucose, bilirubin, creatinine, sodium and potassium) were determined in groups of animals (6/sex/dose) at study termination and following a two-month recovery period. Lung function tests (pulmonary resistance, nitrogen washout, carbon monoxide diffusion, functional reserve capacity, peak expiratory flow, total lung capacity, vital capacity, inspiratory capacity, functional residual capacity, residual volume, specific compliance) were performed on groups of anaesthetised animals (8/sex/dose level, fitted with a tracheal cannula) after 13 weeks exposure and also following a 2-month recovery period using whole body plethysmography. After completion of the lung function tests, animals were subjected to necropsy (including gross examination and collection of organ weight data), followed by histological examination of around 15-20 tissues.

 

There were no deaths during the exposure phase or during the 2-month recovery period. Animals were described as inactive during treatment but no overt clinical signs were present. Body weight was decreased in both the sham control and the diesel-exposed groups relative to animal room controls at the start of exposure (that is, when the animals were first introduced into the chambers). Exposed animals exhibited a reduced weight gain (relative to the sham control group) until the start of the fourth week of treatment (statistically significant for mid- and high dose males and all exposed females), after which male body weight increased while body weights for females remained relatively static. Terminal body weights (after 25 exposures) were significantly decreased by 7%, 13% and 11% in low-, mid- and high-dose males and by 11%, 17% and 16% in the corresponding groups of females, relative to the sham controls. Body weights for exposed males were comparable to the sham control group by the third week of the recovery period, whereas statistically significant decreases remained in mid- and high-dose females until recovery weeks 7 and 5, respectively. Food intake was significantly decreased by approximately 10-15% in mid- and high dose animals (no difference between the sexes) during study weeks 4-12, but did not differ from that of the sham control group thereafter.

 

Breathing frequency was indistinguishable between sham control and exposed animals during the test and recovery periods. Results from the startle reflex tests showed that reaction time was statistically significantly increased in high- and mid-dose males immediately after exposure, and in mid-dose females immediately before exposure, however the magnitude of the alteration (2 msec) was small and considered of doubtful toxicological relevance by the study authors. In contrast, statistically significant increases in peak time were present in high dose males (2-4 msec greater than sham controls) at all of the time points investigated, intermittently in mid-dose males (after the 14thexposure, before the 26thexposure, at one month post-exposure; 2-5 msec) and intermittently in low dose males (after the 14thexposure and at the one month into the recovery phase; 2 -3 msec). Similar statistically significant increases in peak time (increased 2-4 msec) were also present in high- and mid-dose females and persisted for up to one month post-exposure. The magnitude of these differences (up to 5 msec) led the authors to conclude that treatment-related decrement in performance was probably present. There was no obvious treatment-related change in the maximum force exerted by the animals following exposure to the noise stimulus.

 

The number of alveolar macrophages in pulmonary lavage fluid was increased 8-19% in exposed animals of both sexes (significant for low- and high-dose groups), but had resolved by the end of the 2-month recovery period (numbers of other cells unaffected). Pulmonary function tests showed no obvious dose-related difference or trend in lung resistance, multibreath nitrogen washout, single breath carbon monoxide diffusing capacity, maximal forced exhalation, peak expiratory flow, vital capacity, inspiratory capacity, functional residual capacity or specific compliance. Only total lung capacity and residual volume were altered by treatment, with statistically significant decreases (-7% and -13%, respectively) noted in high-dose animals (both sexes combined) when compared with the sham controls.

 

Relative liver weight (as a proportion of body weight) was statistically significantly increased in high-dose males (+29%) and females (+14%) at study termination, but comparable to the sham controls by the end of the two month recovery period. Similarly the relative wet weight of the right middle lobe of the lung was increased 18-19% (significant) in high-dose males and females immediately post-exposure, with smaller (non-significant) increases of 7-9% present in the mid-dose groups. Kidney, spleen, adrenal and testis weights were comparable for the sham control and the treated groups. Some clinical chemistry parameters were apparently altered in high-dose animals (LDH, cholesterol and creatinine in females at study termination; LDH in males 2 month post-exposure), however the report discounts the biological relevance of the findings and the data are not reported. Red cell and white cell counts were unaffected.

 

Histopathological examination of lung revealed no treatment-related lesions, while findings in the kidney (glomerulosclerosis), adrenal (small cortical adenomas) and heart (degeneration of single cardiac fibres) occurred at a similar frequency in control and treated animals and were considered spontaneous phenomena, unrelated to treatment. No treatment-related lesions were present in 15-20 other tissues that were sampled and subjected to microscopic evaluation. This included the nasal turbinates, where no adverse changes were present even in high-dose animals.

 

These results demonstrate statistically significant alterations in a number of parameters (body weight, food consumption, startle reflex, certain lung function parameters) in rats following sub-chronic inhalation exposure to diesel aerosol, however the magnitude of these changes was small suggesting that they are of doubtful biological relevance. Statistically significant increases in relative liver weight and relative wet lung weight were observed in animals exposed to 1710 mg/m3(actual concentration) diesel aerosol for 13 weeks, however there was no histopathological involvement, again making the relevance of these findings unclear.  It is noted that the use of whole body exposure probably resulted in ingestion of the test sample during grooming, and may account for the systemic findings that were observed. All of the changes present following 13 weeks exposure were reversed after a 2-month recovery period. A conservative sub-chronic NOAEC of 0.88 mg/L (analytical concentration) was determined for local effects on the lung (increased relative wet weight in the absence of histopathological change). A NOAEC of greater than or equal to 1.71 mg/L was established for systemic effects, based on no significant findings at this level.

 

Dermal Toxicity

A recent study to OECD 411 and GLP was conducted on a member of the VHGO category. This showed low systemic toxicity (NOAEL 600 mg/kg/day), with higher doses not possible due to excessive local irritation. This study was conducted on a substance in the category low in PAH content (the constituent expected to drive toxicological hazard).

 

In a key subacute dermal toxicity study, Naval Distillate was administered to male and female Sprague Dawley rats at does levels of 0.0001, 0.005, and 0.5 mL/kg (Klimisch score = 2, ARCO 1992e). The test material produced slight dermal irritation at a dose of 0.005 mL/kg and severe irritation at a dose of 0.50 mL/kg as evidenced by grossly visible dermal irritation and microscopic changes in the skin. A dose-dependent decrease in mean triglyceride was noted in males at a dose of 0.50 mL/kg. No other treatment related effects were observed in any of the parameters evaluated. The NOEL level based on dermal irritation was 0.0001 mL/kg and a NOEL of 0.5 mL/kg was calculated for systemic toxicity. 

 

In assorted subacute dermal toxicity studies, VGOs/HGOs/Distillate fuels were applied to the skin of rats. In a supporting subacute dermal toxicity study Naval Distillate was administered to male and female Sprague Dawley rats at does level of 0.50 mL/kg (Klimisch = 2, ARCO 1994a). The dermal irritation NOAEL is <0.50 ml/kg based on slight to moderate dermal irritation observed in the treated rats. In a supporting subacute dermal toxicity study Light Vacuum Gas Oil was administered to male and female Sprague Dawley rats at dose levels of 0.05, 0.25 and 1.0 ml/kg (Klimisch score = 2, ARCO 1993j). Based on the results of this study, the NOEL for dermal irritation was calculated to be less than 0.05 ml/kg for males and 0.05 ml/kg for females. The systemic NOEL was determined to be 1.00 ml/kg for males and 0.25 ml/kg for females. In a supporting subacute dermal toxicity study Sweet Distillate was administered to male and female Sprague Dawley rats at dose levels of 0.05, 0.25 and 1.0 ml/kg (Klimisch score = 2, ARCO 1992f). Based on the results of the study, the dermal irritation NOEL was determined to be less than 0.05 ml/kg and the systemic NOEL was determined to be 1.0 ml/kg. In a supporting subacute dermal toxicity study, a blended diesel fuel was applied to the shaved skin of male and female Sprague Dawley rats at dose levels of 0.5, 1.0, 2.5, 5.0, and 10.0 mL/kg (Klimisch score = 2, ARCO 1988h). The NOAEL was determined to be 1.0 ml/kg (highest dose tested) because of the lack of systemic toxicity and reversible dermal irritation observed at this dose level. In a supporting subacute dermal toxicity study, Cherry Point Diesel Fuel Number 2 was applied to the shaved skin of 10 male and 10 female Sprague Dawley rats at dose levels of 0, 0.5, 2.0, and 5.0 ml/kg (Klimisch score = 2, ARCO 1986j). The NOAEL was determined (by the reviewer) to be 2.0 ml/kg based on the lack of systemic effects observed at this dose level. In a supporting subacute dermal toxicity study Naval Distillate Watson was administered to male and female Sprague Dawley rats at dose levels of 0.25, 2.0 and 5.0 mL/kg (Klimisch score = 2, ARCO 1986k). The NOEL was determined to be 5.0 ml/kg because the dermal effects observed were reversible and no systemic toxicity was observed through the course of the study period at the highest dose tested. In a supporting subacute dermal toxicity study, Watson Diesel Fuel Number 2 was applied to the shaved skin of 10 male and 10 female Sprague Dawley rats at dose levels of 0, 0.5, 2.0, and 5.0 ml/kg (Klimisch score = 2, ARCO 1986l). The NOEL for dermal toxicity was determined (by the reviewer) to be 2.0 ml/kg based on the decrease in body weight noted in male rats at the highest dose tested (5.0 ml/kg).

 

The subchronic dermal toxicity (Klimisch score = 2, Mobil 1989a) of a vacuum gas oil was evaluated in a key study at doses of 0, 30, 125 or 500 mg/kg/day 5 days a week for 13 weeks. Body weight gain was slightly lower in high-dose males (-12%) and females (-7%) compared to the controls and, as a result, high-dose males weighed significantly less than control males during weeks 8 to 13, and high-dose females during week 11 only. Terminal body weights were decreased 3-7% (non-significant) in high-dose males and females, respectively, while those of the other treated groups were indistinguishable from the controls. No clinical signs and only minimal skin irritation (flaking with slight erythema in treatment groups) was observed in the study. Haematological results showed that red cell counts, haemoglobin concentration and haematocrit were significantly altered in mid-dose and high-dose animals. Results from clinical chemistry determinations at week 13 indicated dose-related effects on serum urea nitrogen and cholesterol, with alterations in other isolated parameters in high-dose animals only. Absolute liver weights were increased by 12-19% in mid-dose animals (significant for males only) and by 18-35% in high dose animals (significant in both sexes), while absolute thymus weights were decreased significantly in both sexes by approximately 30-40%. As a proportion of body weight, relative liver weights remained significantly increased relative to controls for the mid (16%) and high- (30-40%) dose groups, while relative thymus weights were significantly decreased (approx. 30%). No microscopic alterations were detected in the liver, however a slight reduction of thymocytes (lymphoid elements) was noted in thymus from males and females treated with 500 mg/kg body weight/day. Examination of skin from the treatment site revealed a non-specific, reversible increase in mitosis of basal cells of the epidermal epithelium in high dose animals only. Results of sperm evaluations showed no treatment-related effects.

 

Based on changes in haematological parameters (decreased RBC, haemoglobin, HCT), clinical chemistry values (increased urea nitrogen and cholesterol) parameters and organ weight effects (increased liver weight, decreased thymus weight), a sub-chronic dermal NOAEL of 30 mg/kg body weight/day appears appropriate for vacuum tower overheads. The NOAEL for local effects was 125 mg/kg body weight/d, based on histopathological changes present at the application site.

 

In a supporting subchronic dermal toxicity study,diesel fuel (F-237) was applied to the shaved skin of rats at dose levels of 0, 0.01, 0.10, or 1.00 mL/kg bw/day (Klimisch score = 1, ARCO 1994b). There was moderate dermal irritation in the high-dose, slight dermal irritation in the mid-dose group, and very slight dermal irritation in the low-dose group. Body weight was decreased in high-dose males, but food consumption was increased in both sexes of the high-dose group. Changes in differential leukocyte counts, decreased albumin (and albumin/globulin ratio), and increased incidence of lymphoid hyperplasia of the auxilliary lymph node also occurred in the high-dose group and were considered to be secondary to the dermal irritation. The systemic LOAEL is 1.00 mL/kg/day based on moderate dermal irritation accompanied by decreased body weight (males only), increased food consumption, changes in differential leukocyte counts, decreased albumin (and albumin/globulin ratio), and increased incidence of lymphoid hyperplasia of the auxilliary lymph node. The NOAEL is 0.1 mL/kg/day (approximately 84 mg/kg/day).

 

The key subacute dermal toxicity study was selected because its conservative NOAEL captures the worst-case scenario of the available data. However, with the availability of subchronic dermal toxicity data, that information will be used for risk characterisation. 

 

Additional data support that VGOs/HGOs/Distillate fuels are not harmful after repeated doses (API, 1980aa; API, 1980bb; API, 1980a; API, 1980b; Easley et al., 1982; API, 1983c; API, 1983d; IIT Research Institute, 1984; Kainz and White, 1984; API, 1986a; NTP, 1986; Dalbey et al., 1987; Mobil, 1989; CONCAWE, 1993; Dally et al., 1996, Nessel et al., 1998). This information is presented in the dossier.

 

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:

Oral study not required as ingestion is not a major route of exposure

 

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:

one of 3 studies on diesel fuel vapour/aerosol

 

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:

increased lung weight observed in the absence of significant histopathology

 

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:

90-day study with the lowest NOAEL

 

Repeated dose toxicity: dermal - systemic effects (target organ) cardiovascular / hematological: thymus; cardiovascular / hematological: other; digestive: liver

Justification for classification or non-classification

There were no data for classification of repeated dose toxicity for oral exposure of VGO/Hydrocracked/Distillate fuels.  A NOAEC of > 1710 mg/m3 will be carried forward for risk characterisation of systemic effects following sub-chronic exposure to aerosolised diesel fuel. A NOAEL of 30 mg/kg body weight/day, reflecting dose-related changes in liver and thymus, will be carried forward for risk characterisation of systemic effects following sub-chronic dermal exposure to vacuum tower overheads. The NOAEL for subchronic dermal local effects was 125 mg/kg body weight/day.

 

Based on these data VGOs/HGOs/Distillate fuels are classified as H373 under the EU CLP Regulation,(EC)1272/2008, criteria.