Hexadecyl 3,5-bis-tert-butyl-4-hydroxybenzoate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08-22 November 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nohsan, Notification No 8147, April 2011; including the most recent partial revisions.

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

CYASORB® UV-2908 Light Stabilizer

IUPAC Name:

CYASORB® UV-2908 Light Stabilizer

Details on test material:

- Name of test material (as cited in study report): CYASORB® UV-2908 Light Stabilizer
- Substance type: White to off-white powder
- Physical state: Powder
- Purity: >98%
- Lot/batch No.: WP1022803
- Expiration date of the lot/batch: 18 April 2013
- Storage condition of test material: At room temperature protected from light
- Hygroscopic: No
- Volatile: No
- Reactivity: Reactive to oxygen, moisture and light
- Test substance handling:
For oxygen and moisture: no specific handling required
For light: use amber-coloured glassware or wrap container in aluminium foil
- pH (1% in water, indicative range): 7.2 – 6.7 (determined at WIL Research Europe B.V.)
- Stability in vehicle Propylene glycol: Stable for approximately 2 hours
- Solubility in vehicle Propylene glycol: Not indicated

Test animals

Species:

rat

Strain:

other: Wistar strain, Crl:WI (Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: Young adult animals (approx. 11 weeks old)
- Weight at study initiation: Body weight variation was within +/- 20% of the sex mean (males: 317 grams; females:207 grams).
- Housing: Individual housing in labeled Macrolon cages
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle.

IN-LIFE DATES: From: 08 to 22 November 2012

Administration / exposure

Type of coverage:

occlusive

Details on dermal exposure:

One day before exposure (Day -1) an area of approximately 5x7 cm on the back of the animal was clipped.

The test substance formulation was applied in an area of approx. 10% of the total body surface, i.e. approx. 25 cm² for males and 18 cm² for females. The test substance formulation was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D)*, successively covered with aluminum foil and Coban elastic bandage*. A piece of Micropore tape* was additionally used for fixation of the bandages in females only.

Frequency: Single dosage, on Day 1.

Washing: Following application, dressings were removed and the skin cleaned of residual test substance using tap water.

Duration of exposure:

24 hours.

Doses:

2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

VEHICLE Propylene glycol (Merck, Darmstadt, Germany) (specific gravity 1.036)
- Justification for choice of vehicle: The vehicle was selected based on trial formulations performed at WIL Research Europe and on test substance data supplied by the sponsor.

Dose volume: 10 mL/kg

DOSAGE PREPARATION: The formulation (w/w) was prepared within 2 hours prior to dosing using amboured coloured glassware. Homogeneity was accomplished to a visually acceptable level. Adjustment was made for specific gravity of the vehicle. No correction was made for purity of the test substance.

Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: Twice daily.
Body weights: Days 1 (pre-administration), 8 and 15.
Clinical signs: At periodic intervals on the day of dosing (Day 1) and once daily thereafter, until Day 15.
- Necropsy of survivors performed: At the end of the observation period, all animals were sacrificed by oxygen/carbon dioxide procedure and subjected to necropsy. Descriptions of all internal macroscopic abnormalities were recorded.
- Other examinations performed: none.

Statistics:

None.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Chromodacryorrhoea was noted in two males and two females on Day 1. In addition one female showed piloerection on Day 1. Scales and/or white staining were seen in the treated skin-area of two males and two females during the observation period. One male

Gross pathology:

No toxicological significant abnormalities were found at macroscopic post mortem examination of the animals.

One male showed an enlarged left kidney with watery content and a dilated ureter on the left side.
Based on the incidence this is considered not toxicologically significant.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute dermal toxicity study with rats, performed according to OECD/EC test guidelines, an LD50 >2000 mg/kg bw was determined.

Based on these results, CYASORB® UV-2908 Light Stabilizer does not have to be classified and has no obligatory labelling requirement for acute dermal toxicity according to the:
- Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2011),
- Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures.