Foots oil (petroleum), hydrotreated

Repeated dose toxicity: dermal

Administrative data

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1985-04-15 to 1985-05-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study is considered reliable without restriction because it was conducted according to OECD Guideline 410.

Justification for type of information:

Concawe believes that dermal is the most relevant exposure route, and is sufficiently robust, to identify any potential hazards from repeated exposures to petroleum products to be able to adequately manage the potentially associated risks. However, the primary objective of the testing required for REACH is the identification of hazard, for which the default exposure route under the regulation is oral as this is considered to maximise systemic exposure. To address the regulatory exposure route issue, Concawe will review the current data base for evidence of systemic toxicity after dermal exposure and will also conduct a number of oral OECD 422 studies on prioritized substances in each relevant petroleum category. The document attached provides a concise overview of the information to further support the dermal route of exposure and proposed additional work, as part of a larger testing strategy (the strategy document can be found in Annex 13).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)

GLP compliance:

yes

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Hydrotreated heavy naphthenic oil, sufficiently refined, IP 346 < 3% (CAS # 64742-52-5)

IUPAC Name:

Hydrotreated heavy naphthenic oil, sufficiently refined, IP 346 < 3% (CAS # 64742-52-5)

Details on test material:

- Name of test material (as cited in study report): API 83-15 Hydrotreated Heavy Naphthenic Distillate, CAS # 64742-52-5
- Substance type: Other Lubricant Base Oil (Sufficiently refined, IP 346 <3%)
- Physical state: Clear Yellow Viscous Liquid
- Analytical purity: Not reported
- Impurities (identity and concentrations): Not reported

- Purity test date: Not reported
- Lot/batch No.: Not reported
- Stability under test conditions: Not reported
- Storage condition of test material: Room temperature
- Viscosity SSU: 3737 @ 100°F
- Color (ATSM) - <2.5
- Pour Point °F: 30
- Aniline Point °F: 194.4
- Flash Point °F, COC: 480
- Gravity, API: 19.2
- Distillation Range D1160: 814 - 1030 (10% - 87%)
- Initial Boiling Point °F: 665

- Composition of test material:
Saturates: 58.7%
Aromatics: 37.1%
Polar Compounds: 4.1%

Sulfur 0.1 wt%

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hazleton Dutchland, Inc. (Denver, Pennsylvania)
- Age at study initiation: Not reported
- Weight at study initiation: Male - 2.4 to 3.1 Kg; Female - 2.4 to 3.0 Kg
- Fasting period before study: Not reported
- Housing:Individually in stainless steel cages with grid bottoms
- Diet (e.g. ad libitum): Purina® Laboratory Rabbit Chow® ad libitum
- Water (e.g. ad libitum): ad libitum via automatic watering system
- Acclimation period: 18 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 3°C
- Humidity (%): 29-80%
- Air changes (per hr): 10-14
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

IN-LIFE DATES: From: 1985-03-28 To: 1985-05-17

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: Dorsal trunk
- % coverage: 10%
- Type of wrap if used: Polyethylene material secured by hypoallergenic tape
- Time intervals for shavings or clippings: 24 hours prior to first application and as necessary thereafter


REMOVAL OF TEST SUBSTANCE
- Washing (if done): gentle wipe with a dry, clean absorbent guaze pad
- Time after start of exposure: 6 hours


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0, 200, 1000, or 2000 mg/kg body weight
- Constant volume or concentration used: no (volume calculated based on weekly body weight)


USE OF RESTRAINERS FOR PREVENTING INGESTION: no

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

6 hours/exposure

Frequency of treatment:

3/week for 4 consecutive weeks

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 200, 1000, 2000 mg/kg
Basis:
nominal per unit body weight

No. of animals per sex per dose:

5/sex/dose

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: Based on pilot test
- Rationale for animal assignment (if not random): Randomized
- Section schedule rationale (if not random):

Positive control:

Positive control not used

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily with 6 hour intervals
- Cage side observations checked in table [No.?] were included: A list of cage side observations was not reported


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Twice daily


DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: Prior to TS administration and once daily thereafter


BODY WEIGHT: Yes
- Time schedule for examinations: Day 1 of study, once weekly thereafter, and prior to termination


FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No


WATER CONSUMPTION: No


OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Post termination
- Dose groups that were examined: 0, 200, 1000, and 2000 mg/kg

ORGAN WEIGHTS: Yes

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At termination
- Anaesthetic used for blood collection: Yes (T-61®)
- Animals fasted: No data
- How many animals: 5/sex/dose
- Parameters checked in table [No.1] were examined: Yes


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At termination
- Animals fasted: No data
- How many animals: 5/sex/dose
- Parameters checked in table [No.2] were examined: Yes


URINALYSIS: No, urine collected for possible future evaluation
- Time schedule for collection of urine: Urine collected prior to dosing and at Termination
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (see Table 3)
HISTOPATHOLOGY: Yes (see Table 3)

Statistics:

Body weights, clinical pathology, and absolute and relative organ weight data of the treated groups were statistically compared to the control group data of the same sex, using a two-tailed Student's t-testf at the 5% probability level.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Dermal irritation:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality was observed in control animals or at any dose level tested.

One male and one female rabbit in the high-dose group (2000 mg/kg) exhibited decreased food intake on days 25-29 and days 10-17, respectively. The same female animal had soft feces and a soiled anal area on Days 10-17 and appeared thin from Days 16-29. These were considered incidental to treatment with API 83-15 by the study authors.

Dermal administration of API 83-15 at 200 mg/kg caused minimal irritation in male (24 of 28 days) and female (26 of 28 days) rabbits. No edema was observed at this dose. For the 1000 mg/kg dose, the daily mean irritation score was in the slight irritant range 17 out of 28 days for males and 16 out of 28 days for females. Mean irritation scores were 1.1 and 1.2 for males and females, respectively. Erythema (1 or 2) was constantly observed in both male and female animals at this dose from Days 16 to 27 of the study. No edema was observed in either male or female rabbits at the 1000 mg/kg dose level. Animals administered API 83-15 at 2000 mg/kg had mean dermal irritation scores of 1.2 and 1.7 for males and females, respectively. Irritation was observed on 15 of 28 days in male and 17 of 28 days in female rabbits at this dose level. Moderate erythema (MIS = 2.2) was observed in males on Days 17 and 25 and in females (MIS = 2.2 - 2.6) on Days 20, 21, and 24 through 28. Slight edema was seen in one male rabbit on day 17 and minimal edema observed in one female rabbit on Day 19 of the study. Flaking skin was also visible in one female in the high-dose group on Day 23.


BODY WEIGHT AND WEIGHT GAIN
Mean terminal body weights for males and females in the 2000 mg/kg dose group were observed to be lower (statistically significant) than control.Three of five male rabbits and four of five female rabbits from the high-dose group (2,000 mg/kg body weight) lost weight over the course of the study. Body weights for male rabbits in the high-dose group at Days 15, 22, 29, and overall mean body weight change were significantly lower than control. For high-dose females, the Day 29 mean weight and the overall weight change were lower (statistically significant) than control. These findings were considered to be treatment-related. Mean body weight gain in the low-dose (200 mg/kg) and mid-dose (1000 mg/kg) dose group appeared to be normal in male and female rabbits.


HAEMATOLOGY
No treatment-related findings were observed in the hematology parameters measured.

CLINICAL CHEMISTRY
SGOT values were observed to be elevated in male rabbits in the 1000 and 2000 mg/kg dose group and in females in the 2000 mg/kg dose group. SGPT values were also elevated in the 1000 and 2000 mg/kg dose level males. Total protein values for females in the 2000 mg/kg dose group were found to be significantly lower when compared to control animals. All these observations are considered to be treatment-related by the study authors.

URINALYSIS
Not conducted

NEUROBEHAVIOUR
Not conducted

ORGAN WEIGHTS
Significantly lower mean absolute heart weight and mean absolute thyroid weights of males in the high-dose (2000 mg/kg) dose group were not considered treatment-related since the relative weights of these organs were not lower than the contols. Significantly lower mean absolute and relative right adrenal weights were considered incidental and not treatment-related since a dose-response was not observed and these values were within the normal range. Mean relative liver weight in females belonging to the 2000 mg/kg dose group was significantly higher than control animals and considered treatment-related. Significant increases in the mean relative right kidney weight in females dosed at 2000 mg/kg were considered sporadic and not treatment-related. Statistically significant increases in the mean absolute and relative right and left adrenal weights in females dosed at 2000 mg/kg was considered treatment-related, although indirectly related to toxic stress.

GROSS PATHOLOGY
Yellow discolorations were observed in the livers of low-dose rabbits with one mid-dose male exhibiting a prominent lobular pattern. Two males in the 2000 mg/kg dose group exhibited yellow granular surface or white nodular areas and four female rabbits in the 2000 mg/kg dose group exhibited prominent lobular patterns in their livers.

HISTOPATHOLOGY: NON-NEOPLASTIC
Minimal to slight epidermal hyperplasia and hyperkeratosis of the skin were present in two male and two female rabbits treated with 2000 mg/kg of API 83-15. The testes of one male in the high-dose group had unilateral diffuse tubular hypoplasia. Nine of ten male female rabbits in the high-dose treatment exhibited a slight to moderately severe multifocal or diffuse hepatocytomegaly accompanied by a minimal to moderate multifocal subacute hepatitis in the liver.

Effect levels

Dose descriptor:

NOAEL

Effect level:

ca. 1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: SGOT and SGPT were elevated at 1000 mg/kg. No other effects were observed at this dose level.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Table 1. Mean Body weight change in male and female rabbits
Dose Level (mg/kg)	Males			Females
	Day 1 (Kg)	Day 29 (Kg)	Weight Gain (kg)	Day 1 (Kg)	Day 29 (Kg)	Weight Gain (Kg)
0 (control)	2.8 (0.2)	3.0 (0.2)	0.2 (0.1)	2.6 (0.1)	3.0 (0.1)	0.3 (0.1)
200	2.6 (0.2)	3.0 (0.1)	0.3 (0.1)	2.7 (0.2)	3.1 (0.2)	0.3 (0.1)
1000	2.7 (0.2)	2.8 (0.1)	0.2 (0.1)	2.6 (0.2)	2.9 (0.4)	0.3 (0.3)
2000	2.8 (0.3)	2.6^*(0.3)	-0.2^*(0.3)	2.7 (0.2)	2.6^*(0.2)	-0.1^*(0.1)

* Statistically significantly lower than control (p = 0.05)

Standard deviation (SD) represented in parenthesis

Table 2a. Mean clinical chemistry values in male rabbits
Dose Level (mg/kg)	Glucose (mg/dL)	BUN (mg/dL)	SGOT (U/L)	SGPT (U/L)	ALP (U/L)	T. PROT (U/L)
0 (control)	113 (14)	15 (4)	16 (4)	30 (9)	84 (18)	4.9 (0.1)
200	117 (16)	15 (2)	16 (4)	30 (9)	80 (31)	5.0 (0.4)
1000	104 (12)	17 (4)	52^*(30)	75^*(30)	94 (26)	5.0 (0.2)
2000	114 (13)	17 (6)	50 (36)	76^*(24)	72 (24)	4.8 (0.3)

* Statistically significantly higher than control (p≤ 0.05)

mg/dL = milligrams per deciliter

U/L = International units per liter

Standard deviation (SD) represented in parenthesis

Table 2b. Mean clinical chemistry values in female rabbits
Dose Level (mg/kg)	Glucose (mg/dL)	BUN (mg/dL)	SGOT (U/L)	SGPT (U/L)	ALP (U/L)	T. PROT (U/L)
0 (control)	113 (10)	21 (4)	20 (4)	33 (8)	118 (27)	5.6 (0.3)
200	108 (12)	19 (5)	18 (5)	34 (20)	136 (24)	5.2 (0.3)
1000	111 (10)	19 (2)	19 (6)	32 (19)	121 (87)	5.0 (0.5)
2000	114 (11)	18 (4)	42^+(15)	77 (48)	79^-(20)	4.9^-(0.5)

+ Statistically significantly higher than control (p≤0.05)

 - Statistically significantly lower than control (p≤0.05)

mg/dL = milligrams per deciliter

U/L = International units per liter

Standard deviation (SD) represented in parenthesis

 

Table 3a. Relative and Absolute organ weights in male rabbits
Dose group (mg/kg)	Heart		Thyroids		Right Adrenal
	Absolute (g)	Relative (%)	Absolute (g)	Relative (%)	Absolute (g)	Relative (%)
0 (Control)	8.16 (0.58)	0.27 (0.03)	0.296 (0.050)	0.010 (0.002)	0.167 (0.041)	0.006 (0.001)
200	8.19 (0.92)	0.28 (0.03)	0.241 (0.052)	0.008 (0.002)	0.118^*(0.010)	0.004^*(0.000)
1000	7.59 (1.28)	0.27 (0.03)	0.241 (0.052)	0.009 (0.001)	0.156 (0.068)	0.005 (0.002)
2000	6.52^*(1.19)	0.25 (0.03)	0.219^*(0.045)	0.008 (0.002)	0.138 (0.019)	0.005 (0.001)

* Statistically significantly lower than control (p≤0.05)

Standard deviation (SD) represented in parenthesis

Table 3b. Absolute and Relative organ weights in female rabbits
Dose group (mg/kg)	Liver		Right Kidney		Right Adrenal		Left Adrenal
	Absolute (g)	Relative (%)	Absolute (g)	Relative (%)	Absolute (g)	Relative (%)	Absolute (g)	Relative (%)
0 (Control)	97.74 (11.74)	3.22 (0.29)	8.36 (0.75)	0.28 (0.03)	0.113 (0.011)	0.004 (0.000)	0.134 (0.024)	0.004 (0.001)
200	87.99 (11.05)	2.88 (0.38)	8.29 (1.07)	0.27 (0.02)	0.123 (0.022)	0.004 (0.001)	0.113 (0.032)	0.004 (0.001)
1000	94.15 (15.49)	3.22 (0.25)	8.88 (1.47)	0.30 (0.03)	0.133 (0.019)	0.005 (0.001)	0.134 (0.024)	0.005 (0.001)
2000	108.65 (18.53)	4.10^*(0.50)	8.75 (1.38)	0.33^*(0.04)	0.180^*(0.027)	0.007^*(0.002)	0.179^*(0.022)	0.007^*(0.001)

* Statistically significantly higher than control (p≤ 0.05)

  Standard deviation (SD) represented in parenthesis

Table 4. Mean dermal irritation scores for male and female rabbits
Dose (mg/kg)	Males	Females
0 (Control)	0.0	0.0
200	0.3	0.6
1000	1.1	1.2
2000	1.2	1.7

0 = Non-irritant

>0 but ≤1= Minimal

>1 but ≤2 = Slight

>2 but ≤5 = Moderate

>5 = Severe

Applicant's summary and conclusion

Conclusions:

Skin irritation ranging from slight to minimal was observed at the mid- and high-dose tested. An increase in liver weight coupled with increases in Serum Glutamic Oxaloacetic Transaminase (SGOT) and Serum Glutamic Pyruvic Transaminase (SGPT) was noted at the 2000 mg/kg dose level. Although SGOT and SGPT levels were also observed to be elevated at the 1000 mg/kg dose level, no other effects were observed at this dose level. Therefore the 28-day repeat dose dermal toxicity NOAEL is determined to be 1,000 mg/kg.

Executive summary:

Read across justification

The physical and chemical properties of foots oils are comparable to the other lubricant base oil intermediate streams from which they are derived. Hence their health effects are also similar to those of other lubricant base oils, and the conclusions of the hazard assessment for other lubricant base oils also apply to foots oils.

In a 28-Day repeat dose dermal toxicity study, five New Zealand White rabbits/sex/dose were topically administered Hydrotreated heavy naphthenic oil six hours/day, three times a week for a period of 28 -days at concentrations of 0, 200, 1000, or 2000 mg/kg body weight.

All animals were observed twice daily for mortality and signs of clinical toxicity and dermal irritation was scored daily (according to the Draize system). Body weights were measured and recorded for each rabbit at the end of the quarantine period, at weekly intervals during the study, and prior to termination.

There was no mortality observed at any concentration tested, and clinical signs such as decreased food consumption, soft stool and staining around the anal region were observed in a few animals in both sexes. Statistically significant treatment-related decreases in mean body weight were observed in males and females at the 2000 mg/kg concentration. High-dose (2000 mg/kg) and mid-dose (1000 mg/kg) males and females were slightly irritated by the administration of hydrotreated heavy naphthenic oil. Low-dose (200 mg/kg) males and females exhibited minimal irritation from administration of the test article. All observed hematology parameters appeared normal in controls and in animals treated with hydrotreated heavy naphthenic oil. SGOT levels were elevated in males exposed at 1000 and 2000 mg/kg and in females administered 2000 mg/kg hydrotreated heavy naphthenic oil. SGPT levels were also elevated in male rabbits exposed to the test material at concentrations of 1000 and 2000 mg/kg. Total protein levels in females at 2000 mg/kg were significantly lower than the control animals. Mean relative liver weight in females exposed at the high-dose were significantly higher than the concommitant control. Statistically significant increases in the mean absolute and relative right and left adrenal weights in females dosed at 2000 mg/kg was considered treatment-related, although indirectly related to toxic stress.Treatment-related gross pathologic findings were confined to the liver and consisted of yellow discolorations in the livers of low-dose rabbits; prominent lobular pattern in one mid-dose male; yellow granular surface or white nodular area in two high-dose males and a prominent lobular pattern in four high-dose females. Topical administration of hydrotreated heavy naphthenic oil at 2000 mg/kg to both male and female rabbits was seen to induce changes in the liver characterized by multifocal to diffuse enlargement of hepatocytes (hepatocytomegaly) accompanied by multifocal areas of inflammation (subacute hepatitis).

The systemic toxicity NOAEL is 1000 mg/kg, based on the lack of adverse systemic effects observed at this dose level.

This study is considered reliable without restriction because it was conducted according to OECD Guideline 410.