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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Conducted according to OECD 402, in full comformance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
GLP compliance:
yes (incl. certificate)
Test type:
fixed dose procedure
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Identification: Tert-butyl peroxybenzoate
CAS# 614-45-9
Description: Colorless liquid
Batch Number: 0903225181
Purity: 99.2%
Stability of Test Item: Stable under storage conditions.
Expiry Date: 01-Apr-2010
Storage Conditions: In a refrigerator (2 - 8 °C) away from direct sunlight.

Test animals

Species:
rat
Strain:
other: RccHan:WIST(SPF)
Sex:
male/female
Details on test animals and environmental conditions:
Test System
Animals: Rat, RccHanTM: WIST(SPF)
Rationale: Recognized by international guidelines as a
recommended test system.
Breeder: Harlan Laboratories B.V.
Kreuzelweg 53
5961 NM Horst / The Netherlands
Number of Animals per Group: 5 males and 5 females
Total Number of Animals: 5 males and 5 females
Age (when treated): Males: 9 weeks
Females: 12 weeks
Body Weight Range (when treated): 232.2 g - 259.0 g (males)
186.6 g - 196.6 g (females)
Identification: Unique cage number and corresponding color-coded
spots on the tail. The animals were marked at
acclimatization start.
Randomization: Selected by hand at time of delivery.
No computer generated randomization program.
Acclimatization: Under laboratory conditions, after health
examination. Only animals without any visible signs
of illness were used for the study.

Husbandry
Room Number: Harlan Laboratories Ltd. / Itingen, 1OG.133A
Conditions: Standard Laboratory Conditions. Air-conditioned
with 10 - 15 air changes per hour, and continuously
monitored environment with ranges for room
temperature 22 ± 3 °C and for relative humidity
between 30 - 70% (values above 70% during
cleaning process possible), automatically controlled
light cycle of 12 hours light and 12 hours dark,
music during the daytime light period.
Accommodation: During acclimatization in groups of five per sex in
Makrolon type-4 cages with standard softwood
bedding. Individually in Makrolon type-3 cages with
standard softwood bedding (‘Lignocel’ J. Rettenmaier
& Söhne GmbH & Co. KG, 73494 Rosenberg
/ Germany, imported by Provimi Kliba AG,
4303 Kaiseraugst / Switzerland) during treatment
and observation.
Diet: Pelleted standard Provimi Kliba 3433 rat/mouse
maintenance diet, batch no. 58/09 (Provimi Kliba
AG, 4303 Kaiseraugst / Switzerland) ad libitum.
Results of respective analyses for contaminants are
included.
Water: Community tap water from Itingen ad libitum.
Results of bacteriological assay, chemical and
contaminant analyses of respective samples are
included.

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
One day before treatment, the backs of the animals were clipped with an electric clipper,
exposing an area of approximately 10% of the total body surface.
Only those animals without injury or irritation on the skin were used in the test.
On test day 1, the test item was applied at a dose of 2000 mg/kg body weight evenly on the intact
skin with a syringe and covered with a semi-occlusive dressing. The dressing was wrapped
around the abdomen and fixed with an elastic adhesive bandage.
Application volume/kg body weight: 2 mL
Twenty-four hours after the application the dressing was removed and the skin was flushed with
lukewarm tap water and drapped off with disposable paper towels. Thereafter, the reaction sites
were assessed.
Duration of exposure:
24 h
Doses:
2000 mg/kg (2ml/kg)
No. of animals per sex per dose:
5M & 5F
Control animals:
no
Details on study design:
Preparation of Dose Formulations
Dose levels are in terms of the test item as supplied by the Sponsor.
The test item was applied undiluted as delivered from the Sponsor. The doses were calculated
based upon the rats’ body weight.

Test Item Administration
One day before treatment, the backs of the animals were clipped with an electric clipper,
exposing an area of approximately 10% of the total body surface.
Only those animals without injury or irritation on the skin were used in the test.
On test day 1, the test item was applied at a dose of 2000 mg/kg body weight evenly on the intact
skin with a syringe and covered with a semi-occlusive dressing. The dressing was wrapped
around the abdomen and fixed with an elastic adhesive bandage.

Application volume/kg body weight: 2 mL

Twenty-four hours after the application the dressing was removed and the skin was flushed with
lukewarm tap water and drapped off with disposable paper towels. Thereafter, the reaction sites
were assessed.

Rationale
Dermal administration was used as this is one possible route of human exposure during
manufacture, handling and use of the test item.

Observations
Viability / Mortality: Daily during the acclimatization period, within the
first 30 minutes and at approximately 1, 2, 3 and 5
hours after administration on test day 1 (with the
clinical signs) and twice daily during days 2 - 15.

Clinical Signs: Daily during the acclimatization period, within the
first 30 minutes and at approximately 1, 2, 3 and 5
hours after administration on test day 1. Once daily
during days 2 - 15.

Local Dermal Signs: Once daily during days 2 (following dressing
removal) through day 15 using the numerical scoring
system described in Appendix IV on p. .
Body Weights: On test days 1 (prior to administration), 8 and 15.
Pathology
Necropsy
All animals were killed at the end of the observation period by an intraperitoneal injection of
vetanarcol at a dose of at least 2.0 mL/kg body weight (equivalent to at least 324 mg sodium
pentobarbitone/kg body weight) and discarded after macroscopic examinations were performed.
An external examination and opening of the abdominal and thoracic cavities for examinations of
major organs were performed. The appearance of any macroscopic abnormalities was recorded.
No organs or tissues were retained.

Determination and Scoring of Clinical Signs and Local Dermal Signs
Observation
Data were summarized in tabular form, showing for each individual animal the clinical and local
signs at each measurement interval. All findings were described.
The skin reaction was assessed according to the numerical scoring system listed in the
Commission Regulation (EC) No 440/2008 B.4 (see Appendix IV on p. ).

Statistical Analysis
No statistical analysis was used.

Data Compilation
Body weights were recorded on-line.
Clinical and local dermal signs were recorded on data sheets.

Mortality/viability were compiled into the RCC Tox Computer System during recording and/or
recorded on data sheets.

Macroscopic findings were compiled into the RCC Tox Computer System during recording.
The RCC Tox Computer System (RCC-Tox-Lims) had been validated with respect to data
collection, storage and retrievability.
Statistics:
none

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LD0
Effect level:
2 000 mg/kg bw
Based on:
test mat.
Mortality:
none
Clinical signs:
none
Body weight:
not affected
Gross pathology:
dermal irritation
Other findings:
Generalized erythema, slight in degree, was noted in all animals after removal of the semiocclusive
bandage 24 hours after administration. This finding was noted Initally in all males,
(persisting between two and five days) and in all females (persisting for one to five days). Slight
to moderate desquamation was noted in all five males and two of five females, with localized
necrotic areas in one male and one female which persisted until the last day of observation.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
The median lethal dose of tert-butyl peroxybenzoate after single dermal administration to rats of
both sexes, observed over a period of 14 days, is:
LD50 (rat): greater than 2000 mg/kg body weight
Executive summary:

Five male and five female RccHan:WIST (SPF) rats were treated with tert-butyl peroxybenzoate at 2000 mg/kg by dermal application. The test item was applied undiluted as delivered from the Sponsor at a volume dosage of 2 mL/kg. The application period was 24 hours. The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2 - 15. Local signs were noted once daily from test day 2 to 15. Mortality/viability was recorded within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2 - 15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically. No deaths occurred during the study. No clinical signs were evident during the course of the study. The body weight of the animals was within the range commonly recorded for this strain and age. Local effects included slight generalized erythema Initally in all males and females. This finding persisted up to five days in both sexes, although males seemed to be more susceptible. Slight to moderate desquamation, noted in all five males and two of five females, was accompanied by localized necrotic areas in one male and one female. This latter finding persisted until the last day of observation. At necropsy, dermal sores were noted on the treated skin of two males (nos. 1 and 4) and one female (no. 10) and were considered to be related to the treatment with the test item. The median lethal dose of tert-butyl peroxybenzoate after single dermal administration to rats of both sexes, observed over a period of 14 days, is: LD50 (rat): greater than 2000 mg/kg body weight