2-methylpentane-2,4-diol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented, according to accepted guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987 followed; reliability scoring based on 2002 guideline

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpentane-2,4-diol

EC Number:

203-489-0

EC Name:

2-methylpentane-2,4-diol

Cas Number:

107-41-5

Molecular formula:

C6H14O2

IUPAC Name:

2-methylpentane-2,4-diol

Details on test material:

- Name of test material (as cited in study report): Hexylene glycol
- Physical state: liquid
- Analytical purity: 99.72%
- Stability: stable for one year, no expiry date was given
- Storage: room tempertaure in an unlit cabinet

Test animals

Species:

rat

Strain:

other: Crl:CD. BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd., Margate
- Age at study initiation: Males were 6 to 8 weeks old and females were 9 to 10 weeks old
- Weight at study initiation: Males 260 - 284 g; Females 229 - 239
- Fasting period before study: None
- Housing: The rats were individually caged in suspended stainless steel mesh cages
- Diet (e.g. ad libitum): SQC(E) Rat and mouse maintenance diet No 1, from Special Diets Services, Ltd, Witham was available ad libitum
- Water (e.g. ad libitum): Mains water was provided ad libitum via cage-mounted water bottles
- Acclimation period: 8 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25
- Humidity (%): 40 to 70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: area of the dorsum cover by a 5 X 5 cm dense gauze patch
- % coverage: 10% of total body surface
- Type of wrap if used: patch was kept in place by a elasticated, open weave adhesive bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): swabbed with moist cotton wool

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2.22 mL/kg body weight
- Constant volume or concentration used: no, individual dose volumes were calculated from the body weights of the rats on the morning of dosing using the 2.22 mL/kg body weight dose volume and the specific gravity of the test article (0.9 g/mL)

Duration of exposure:

24 hour

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5 males and 5 females

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 15 days
- Frequency of observations and weighing: rats were weighed the day before dosing, on day the day of dosing and days 8 and 15. Clinical signs were recorded frequently on day 1 and regularly for the remainder of the study with the minimum schedule being at least once within half an hour of dosing, four times within 4 hours of dosing, twice daily on days 2, 3, and 4 and once daily from the 5th to last day of the observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: the conditions of each dermal test site was recorded following removal of dressing on day 2. Full necropsy was performed on day 15 and included inspection of external surfaces and orifices, all viscera and tissue within the abdominal, thoracic and cranial cavities, free-hand sectioning of the dermal test site, liver and kidneys

Statistics:

Not reported

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Mortality:

No deaths occured

Clinical signs:

other: No clinical signs

Gross pathology:

Renal pelvic dilatation in 2 rats and an enlarged spleen on one other animal. There were no irritation reactions or other dermal changes in the sites of application of the test article.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

A single (24 hour) semi-occluded topical application of hexylene glycol to rats at a dose level of 2000 mg/kg body weight caused no death. No clinical signs of systemic toxicity or dermal reactions to application of the test article were apparent during the observation period. The acute median lethal dermal dose (LD50) and acute minimum lethal dose of hexylene glycol were found to exceed 2000 mg/kg body weight.

Executive summary:

An acute dermal toxicity study on hexylene glycol has been performed in accordance with OECD Guidelines for the Testing of Chemicals No. 402 and in compliance with GLP (Gardner, 1996). The study was performed in Crl:CD BR rats in which 5 male and 5 female animals were dermally administered 2000 mg/kg body weight of hexylene glycol in a volume of 2.22 mL/kg body weight. The test substance was applied to the dorsal area (10% of total body surface) under semi-occlusive conditions for an exposure period of 24 hours. Animals were observed over a 15-day period. There were no irritation reactions or other dermal changes at the sites of hexylene glycol application. In addition, no deaths occurred and no clinical signs of systemic toxicity were observed. A small loss in weight loss was observed in one female on day 15, but no other effects on body weight were observed. Gross pathology revealed renal pelvic dilatation in 2 rats and an enlarged spleen in one other animal. The dermal LD50 of hexylene glycol was determined to be greater than 2000 mg/kg body weight in rats.