Distillates (petroleum), steam-cracked, C5-12 fraction

Repeated dose toxicity: dermal

Administrative data

Endpoint:

sub-chronic toxicity: dermal

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant, near guideline studies, available as unpublished reports, minor restrictions in design and/or reporting but otherwise adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

only 3 applications/week (12 in total)

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

64741-63-5 (API 83-04) and 68955-35-1 (API 83-05)

IUPAC Name:

64741-63-5 (API 83-04) and 68955-35-1 (API 83-05)

Constituent 2

Reference substance name:

Light catalytic reformed naphtha (Sample API 83-04)

IUPAC Name:

Light catalytic reformed naphtha (Sample API 83-04)

Constituent 3

Reference substance name:

Catalytic reformed naphtha (Sample API 83-05)

IUPAC Name:

Catalytic reformed naphtha (Sample API 83-05)

Details on test material:

- Name of test material (as cited in study report): Light catalytic reformed naphtha (petroleum) API Sample 83-04
- Name of test material (as cited in study report): Light catalytic reformed naphtha API Sample 83-04
- Name of test materials (as cited in study report): Full range catalytic reformed naphtha API Sample 83-05
- Substance types: petroleum derived hydrocarbon
- Composition of test materials, percentage of components: up to 100% aromatics, including substituted mono and diaromatics (including approximately 2-5% benzene)
- Physical state: clear yellowish liquid

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hazleton Dutchland Inc., Denver, Pennsylvania, USA
- Age at study initiation: Not reported
- Weight at study initiation: API 83-04: 2.6-3.2 kg (males), 2.6-3.3 kg (females), API 83-05: 2.5-3.1 kg (males), 2.6-3.2 kg (females)
- Housing: Individually in stainless steel cages with grid bottoms
- Diet: Purina Laboratory Rabbit Chow #5321 ad libitum
- Water: ad libitum
- Acclimation period: 18 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22±3°C (API 83-04), 23±3°C (API 83-05)
- Humidity: 20-70 (%):
- Air changes (per hr): 10-15
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: From: 16 January 1984 To: 17 February 1984 (API 83-04)
IN-LIFE DATES: From: 16 January 1984 To: 14 February 1984 (API 83-04)

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: trunk (approximately 15 cm x 20 cm)
- % coverage: approximately 10% of total body surface
- Type of wrap if used: surgical gauze pad, wrapped with a sheet of polythene and secured with hypoallergenic tape.
- Time intervals for shavings or clippings: approximately 24 hours prior to each application

REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped with a clean dry absorbent gauze pad (not washed).
- Time after start of exposure: 6 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): Based on the weekly bodyweight of each animal and the specific gravity (0.7480 g/mL) of API 83-04.

USE OF RESTRAINERS FOR PREVENTING INGESTION: no

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

28 days

Frequency of treatment:

three times per week (total of 12 applications)

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 200, 1000, 2000 mg/kg (API 83-04 and API 83-05)
Basis:
nominal per unit body weight

No. of animals per sex per dose:

5

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: Doses determined in a pilot 5 day dermal study

Examinations

Observations and examinations performed and frequency:

MORTALITY AND CLINICAL OBSERVATIONS: Yes
- Time schedule: twice daily .

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily (Draize scoring system used)

BODY WEIGHT: Yes
- Time schedule for examinations: At start, weekly thereafter and at termination

FOOD CONSUMPTION: No

WATER CONSUMPTION: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all
- Parameters examined: erythrocyte count, total leukocyte count, differential leukocyte count, haemoglobin, haematocrit, RBC morphology

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all
- Parameters examined: glucose, blood urea nitrogen, alkaline phosphatase, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, total protein

URINALYSIS: No (urine collected from all control and high dose animals prior to initiation of dosing and at termination. Frozen and stored for possible future evaluation).

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
ORGAN WEIGHTS: heart, liver, spleen, kidneys, adrenals, thyroids, pituitary, testes, ovaries, brain
HISTOPATHOLOGY: Yes. The following tissues from all control and high dose animals were examined: heart, lungs, bronchi, trachea, thyroids, parathyroids, cervical lymph nodes, salivary gland, tongue, oesophagus, stomach, duodenum, jejunum, ileum, sacculus rotundus, colon, thymus, spleen, liver, pancreas, kidneys, adrenals, vagina, seminal vesicles, testes/ovaries, epididymides, prostate, uterus, mesenteric lymph nodes, urinary bladder, mammary gland, brain (cerebellum, cerebrum, pons), pituitary, spinal cord (2 sections), skeletal muscle, sciatic nerve, skin (treated and untreated), bone, bone marrow (smear), eyes, gross lesions

Statistics:

2-tailed Student's t-test 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

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY:
API 83-04: No treatment-related mortalities or clinical observations.
API 83-05: One male at 2000 mg/kg/day was found dead on day 12 and another on day 17. One male was killed in extremis at 1000 mg/kg/day on day 19. No consistent treatment-related clinical findings were observed.

DERMAL IRRITATION: Treatment-related findings were present in all API 83-04 and API 83-05 treated groups and consisted of erythema, oedema, cracked skin, atonicity, skin dry and leather-like, flaking skin. The 2000 and 1000 mg/kg/day API 83-04 dose levels were severely irritating to rabbit skin and the 200 mg/kg dose was moderately irritating. The 2000 mg/kg/day API 83-05 dose level was severely irritating to rabbit skin and the 200 and 1000mg/kg doses were moderately irritating.

BODY WEIGHT AND WEIGHT GAIN:
API 83-04: 2000 mg/kg males had statistically significantly lower mean body weight on days 15, 22 and 29 and females were lower on days 22 and 29. Stat sig. lower mean bodyweight gains were present for males at 2000 mg/kg and females at 1000 and 2000 mg/kg.
API 83-05: Overall bodyweight gains for 2000 mg/kg/day males and females were stat. sig. lower than controls.

HAEMATOLOGY: No treatment-related effects

CLINICAL CHEMISTRY: No treatment-related effects

ORGAN WEIGHTS: No treatment-related effects

GROSS PATHOLOGY: Effects confined to treated skin and consisted of thickened, reddened, flaky, fissured, cracked and/or dry skin

HISTOPATHOLOGY: Effects confined to treated skin and consisted of slight to moderate proliferative and inflammatory changes. These inflammatory changes were accompanied by an increased granulopoiesis of the bone marrow probably related to the stress or other factors associated with skin irritation. No other treatment-related effects.

Effect levels

1

Dose descriptor:

NOAEL

Remarks:

API 83-04 systemic toxicity

Effect level:

1 000 mg/kg bw/day (nominal)

Sex:

male

Basis for effect level:

other: Lower bodyweights and bodyweight gain at 2000 mg/kg.

2

Dose descriptor:

NOAEL

Remarks:

API 83-04 systemic toxicity

Effect level:

200 mg/kg bw/day (nominal)

Sex:

female

Basis for effect level:

other: Lower bodyweight at 2000 mg/kg. Lower bodyweight gain at 2000 and 1000 mg/kg.

3

Dose descriptor:

LOAEL

Remarks:

APA 83-04 dermal irritation

Effect level:

200 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: Moderate irritation at lowest dose tested

4

Dose descriptor:

NOAEL

Remarks:

API 83-05 systemic toxicity

Effect level:

200 mg/kg bw/day (nominal)

Sex:

male

Basis for effect level:

other: Mortalities at 1000 and 2000 mg/kg/day

5

Dose descriptor:

NOAEL

Remarks:

API 83-05 systemic toxicity

Effect level:

1 000 mg/kg bw/day (nominal)

Sex:

female

Basis for effect level:

other: Lower bodyweight gain at 2000 mg/kg

6

Dose descriptor:

LOAEL

Remarks:

API 83-05 dermal irritation

Effect level:

200 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: Moderate irritation at lowest dose tested

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Following repeated 6-hour dermal applications to rabbit skin over a period of 28 days (3 times/week, total of 12 applications), the NOAEL of API 83-04 was 1000 mg/kg/day for males and 200 mg/kg/day for females; for API 83-05 the NOAEL was 200 mg/kg/day for males and 1000 mg/kg/day for females.

Executive summary:

Repeated dose (6 hour dermal applications) toxicity of API 83-04 (CAS 64741-63-5) and API 83-05 (CAS 68955-35-1) was investigated in groups of 5 male and 5 female rabbits. The neat test substance was applied to skin over a period of 28 days (3 times/week, total of 12 applications) at doses of 0, 200, 1000 or 2000 mg/kg/day. Animals were observed daily for clinical signs of toxicity and skin irritation, bodyweight was measured at intervals and at the end of the study blood samples were analysed for changes in haematology and clinical chemistry, a selection of organs were weighed and a full range of tissues examined histopathologically.

There were no effects on haematology, clinical chemistry, organ weights or histopathology indicative of systemic toxicity. Treatment-related effects of API 83-04 were confined to lower body weight and body weight gain at 2000 mg/kg/day in males and female, lower body weight gain in females at 1000 mg/kg/day and evidence (visual and histopathological) of moderate to severe skin irritation at all dose levels. Treatment-related effects of API 83-05 comprised mortality in males at 1000 and 2000 mg/kg/day, lower body weight at 2000 mg/kg/day in males and female, and evidence (visual and histopathological) of moderate to severe skin irritation at all dose levels.

The NOAEL for systemic toxicity for API 83-04 (CAS 64741-63-5) was 1000 mg/kg/day for males and 200 mg/kg/day for females.

The NOAEL for systemic toxicity for API 83-05 (CAS 68955-35-1) was 200 mg/kg/day for males and 1000 mg/kg/day for females.

A NOAEL was not established for local irritant effects for either material - 200 mg/kg was a LOAEL based on moderate irritation using Draize scores.