Di-tert-butyl peroxide

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-03-31 to 2010-09-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well-documented study performed under GLP according to established guidelines with no deviations.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Di-tert-butyl peroxide

EC Number:

203-733-6

EC Name:

Di-tert-butyl peroxide

Cas Number:

110-05-4

Molecular formula:

C8H18O2

IUPAC Name:

2-(tert-butylperoxy)-2-methylpropane

Details on test material:

Identification: Di-tert-butyl peroxide (CAS# 110-05-4)
EINECS Number: 203-733-6
Description: Colorless liquid
Batch Number: 0904130207
Purity: 99.0 %
Expiry Date: 01-May-2010
Stability of Test Item: Stable under storage conditions.
Storage Conditions: In freezer (range of -20 ± 5 °C, provided by Harlan Laboratories Ltd.), keep in original container, store separate from other chemicals, away from sources of heat and sunlight. Avoid shock and friction. For archiving: a sample of the test item will be stored at -80 °C in a high-density polyethylene (HDPE) container with a rated embrittlement temperature of -100 °C. Samples must only be thawed by placing them at the recommended storage temperature; for di-tert-butyl peroxide (CAS# 110-05-4), this is -20 °C. Samples must not be thawed by application of heat.
Safety Precautions: A helmet mask was worn during manipulations with the test item. Otherwise, routine hygienic procedures were used to ensure the health and safety of the personnel.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Test Animals:
Animals: Young Adult New Zealand White Rabbit, SPF
Rationale: Recognized by international guidelines as a recommended test system.
Breeder: Charles River Laboratories France, BP 0109, 69592 L’Arbresle / France
Number of Animals per Test: 3 (Animals of both sexes were used)
Age (when treated): 14 weeks (male), 18 weeks (females)
Body Weight Range (when treated): 2826 g (male), 2706 - 2707 g (females)
Identification: By unique cage number and corresponding ear number.
Acclimatization: Under laboratory conditions after health examination. Only animals without any visual signs of illness were used for the study.
Randomization: Selected by hand at time of delivery. No computer generated randomization program.

Environmental Conditions:
Conditions: Standard Laboratory Conditions. Air-conditioned with 10-15 air changes per hour, and continuously monitored environment with a room temperature of 17-23 °C and a relative humidity between 30-70%, automatically controlled light cycle of 12 hours light and 12 hours dark, music during the daytime light period.
Accommodation: Individually in stainless steel cages equipped with feed hoppers and drinking water bowls.
Diet: Pelleted standard Kliba Nafag 3418 rodent maintenance diet (batch no. 05/10) provided by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) available ad libitum. Results of analyses for contaminants are archived at Harlan Laboratories Ltd. A piece of wood (imported by Indulab AG, Gams / Switzerland from ABEDD® - LAB & VET GmbH, 1160 Vienna / Austria) and a haystick 4642 (batch no. 54/09, Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) were also provided for environmental enrichment.
Water: Community tap water from Füllinsdorf ad libitum. Results of bacteriological, chemical and contaminant analyses are archived at Harlan Laboratories Ltd.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 mL of di-tert-butyl peroxide (CAS# 110-05-4) was withdrawn with a syringe and applied undiluted. The test item was applied at 0.1 mL/animal, the dose specified in the test guidelines for a liquid test item.

Duration of treatment / exposure:

Single exposure.

Observation period (in vivo):

72 hours

Number of animals or in vitro replicates:

3 (1 male and 2 females)

Details on study design:

Di-tert-butyl peroxide (CAS# 110-05-4) was used as delivered by the Sponsor.


The pH of the test item was measured from an aliquot of the test item, before the study initiation date. By using pH strips , the pH was found to be 4.

According to Commission Regulation (EC) No 440/2008 B.5. and OECD Guidelines 405, a test item is not required to be tested if the pH-value is less than 2 or greater than 11.5, owing to its predictable corrosive properties.

0.1 mL of di-tert-butyl peroxide (CAS# 110-05-4) was withdrawn with a syringe and applied undiluted. The test item was applied at 0.1 mL/animal, the dose specified in the test guidelines for a liquid test item.

The eyes of the animals were examined one day prior to test item administration. The test item was placed in the conjunctival sac of the left eye of each animal after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of test item. The right eye remained untreated and served as the reference control.

A single animal (one female) was treated first. As neither a corrosive effect nor a severe irritant effect was observed after the 1- and 24-hour examinations, the test was completed using the two remaining animals.

Rationale: The application form and dose were used to detect an irritating potential of the test item applied.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Results 3

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Reversibility:

fully reversible

Results 4

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.33

Reversibility:

fully reversible

Results 5

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Reversibility:

fully reversible

Results 6

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

The instillation of di-tert-butyl peroxide (CAS# 110-05-4) into the eye resulted in mild, early onset and transient ocular changes, such as slight to moderate reddening of the conjunctivae and slight to moderate reddening of the sclerae. Also, slight swelling of the conjunctivae was noted, although exclusively 1 hour after instillation. All effects were reversible and were no longer evident 72 hours after treatment, the end of the observation period for all animals. No abnormal findings were observed in the cornea or for the iris light reflex of any animal at any of the examinations. No corrosion was observed at any of the measuring intervals. No staining of the treated eyes by the test item was observed and no clinical signs were observed.

Other effects:

Coloration: No staining produced by the test item was observed in the treated eyes.
Corrosion: No corrosion of the cornea was observed at any of the reading times.

Any other information on results incl. tables

Viability / Mortality: No intercurrent deaths occurred during the course of the study.

Clinical Signs: No clinical signs were recorded throughout the entire observation period.

Body Weights: The body weight of the animals was within the range commonly recorded for this strain and age.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based upon the referred classification criteria (Regulation (EC) No 1272/2008), di-tert-butyl peroxide (CAS# 110-05-4) is not classified with respect to eye irritation in rabbits.

Executive summary:

The primary eye irritation potential of di-tert-butyl peroxide (CAS# 110-05-4) was investigated according to OECD test guideline no. 405. The test item was applied by instillation of 0.1 mL into the left eye of each of three young adult New Zealand White rabbits. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours after test item instillation.

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after instillation) for each animal for corneal opacity, iris light reflex and redness and chemosis of the conjunctivae. The individual mean scores for corneal opacity and iris light reflex were 0.00 for all three animals. The individual mean scores for the conjunctivae were 1.00, 0.33 and 0.33 for reddening and 0.00, 0.00 and 0.00 for chemosis, respectively.

The instillation of di-tert-butyl peroxide (CAS# 110-05-4) into the eye resulted in mild, early onset and transient ocular changes, such as reddening and swelling of the conjunctivae and reddening of the sclerae. These effects were reversible and were no longer evident 72 hours after treatment, the end of the observation period for all animals. No abnormal findings were observed in the cornea or for the iris light reflex of any animal at any of the examinations. No corrosion was observed at any of the measuring intervals. No staining of the treated eyes by the test item was observed and no clinical signs were observed.

Thus, the test item did not induce significant or irreversible damage to the rabbit eye.

Based upon the referred classification criteria (Regulation (EC) No 1272/2008), di-tert-butyl peroxide (CAS# 110-05-4) is not classified with respect to eye irritation in rabbits.