Di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide

Endpoint summary

Description of key information

Skin Irritation

The test substance LUPEROX 231 (l,I-DI-(tertBUTYLPEROXY)- 3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Eye Irritation

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 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) is not classified with respect to eye irritation in rabbits.

Bovine Corneal Opacity

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No. 6731-36-8) is not considered to be an eye irritant.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 Days

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented study according to OECD 404 and OECD & French Government GLP. Study report includes, QA & GLP statement and C of A for test article.

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Animals
-Sex, species, strain: male New Zealand White rabbits.
-Reason for this choice: species commonly requested by the international regulations for this type of study.
-Breeder: Elevage Cunicole de Val de Selle, 80160 Prouzel, France.
-Number of animals and identification: three animals were used, as recommended by the international regulations and taking into account that a good correlation of results can be obtained with either three or six animals. The animals were identified individually with a metal tag in the ear.
-Weight: on the day of treatment, the animals had a mean body weight ± standard deviation of 2.5 ± 0.2 kg.
-Acclimatization: at least five days before the beginning of the study.

Environmental conditions
During the acclimatization period and during the main test, the environmental conditions in the animal room were set as follows:
-temperature: 18 ± 3°C
-relative humidity: 30 to 70%
-light/dark cycle: 12 hl12 h
The temperature and relative humidity were recorded continuously and records retained.
The housing conditions (temperature, relative humidity and light/dark cycle) were checked
regularly.The animals were housed individually in polystyrene cages (35 cm x 55 cm x 32 cm or
48.2 cm x 58 cm x 36.5 cm). Each cage was equipped with a food container and a water bottle.

Food and water
All the animals had free access to 112 C pelleted diet (U.A.R., 91360 Villemoisson-sur-Orge, France). Each batch of food was analysed (composition and contaminants) by the supplier. Drinking water filtered by a F.G. Millipore membrane (0.22 micron) was provided ad libitum. Bacteriological and chemical analysis of the water and detection of possible contaminants (pesticides, heavy metals and nitrosamines) are performed periodically. Results ar archived at C.I.T. It was verified that no contaminants in the diet or water at levels likely to influence the outcome of the study were present.

Type of coverage:

semiocclusive

Preparation of test site:

other: unabraded

Vehicle:

unchanged (no vehicle)

Controls:

other: each animal served as its own control, untreated sites

Amount / concentration applied:

A single dose of 0.5 ml of the test substance was applied to a 6 cm2 dry gauze pad (Semes France, 54183 Heillecourt, France) which was then applied to the right (application for four hours) or the left flank (application for three minutes) of the animals. The test substance and the gauze pad were held in contact with the skin by means of an adhesive hypoallergenic aerated semi-occlusive dressing (Laboratoires de Pansements et d'Hygiene,
21300 Chenove, France) and a restraining bandage (Laboratoires 3M Sante, 92245 Malakoff, France). After removal of the dressing, any residual test substance was wiped off by means of a dry gauze pad

The untreated skin served as control.

.

Duration of treatment / exposure:

4 hours

Observation period:

three minutes, one hour, 24 hr, 48 hr, 72 hr

Number of animals:

three

Details on study design:

Preparation and selection of the animals
The day before treatment, the flanks of each animal were clipped using electric clippers. The skin of each animal was examined in order to use only
animals without any signs of cutaneous irritation. Animals showing signs of cutaneous irritation, cutaneous defects or pre-existing dermal injury
were not used.

Study design
The study design was established according to available information on the test substance and following the O.E.C.D. and E.C. guidelines. As possible irritant effects were anticipated, a first assay was conducted with one animal. The duration of exposure was three minutes on one flank and four
hours on the other flank. Since the test substance was not strongly irritant in this first assay, it was then applied for four hours in two other animals in second assay.

Application of the test substance
The test substance was used in its original form.
A single dose of 0.5 ml of the test substance was applied to a 6 cm2 dry gauze pad (Semes France, 54183 Heillecourt, France) which was then applied to the right (application for four hours) or the left flank (application for three minutes) of the animals. The test substance and the gauze pad were heldin contact with the skin by means of an adhesive hypoallergenic aerated semi-occlusive dressing (Laboratoires de Pansements et d'Hygiene, 21300 Chenove, France) and a restraining bandage (Laboratoires 3M Sante, 92245 Malakoff, France). After removal of the dressing, any residual test substance was wiped off by means of a dry gauze pad. The untreated skin served as control.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: day 2

Score:

ca. 2

Max. score:

2

Reversibility:

fully reversible

Irritant / corrosive response data:

After three-minute exposure (one animal): Very slight or slight erythema (grade 1 or 2) was observed up to day 3; it was accompanied by slight oedema (grade 2) on day 2 only. Dryness of the skin was noted from days 4 to 7.

After four-hour exposure (four animals)
Very slight or slight erythema (grade 1 or 2) was observed up to day 3 (two animals) or 6. It was accompanied by slight or severe oedema (grade 2 or 4) for 24 hours in all animals. Mean scores over 24, 48 and 72 hours for individual animals were 1.3, 1.0 and 1.0 for erythema and 0.7 for oedema.

Under the conditions fo this test, the test substance LUPEROX 231 (l,I-DI-(tertBUTYLPEROXY)-3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Interpretation of results:

not irritating

Remarks:

Migrated information While a classification of "not irritating" is appropriate under the governing EEC Directive (93/21, April 27, 1993), a four-hour occlusive exposure clearly resulted in short-term irritant response, including severe edema at the end of exposure in 2/3 of t Criteria used for interpretation of results: EU

Conclusions:

CONCLUSION
Under these experimental conditions, the test substance LUPEROX 231 (l,I-DI-(tertBUTYLPEROXY)- 3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Executive summary:

RESULTS

-After three-minute exposure (one animal): Very slight or slight erythema (grade 1 or 2) was observed up to day 3; it was accompanied by slight oedema (grade 2) on day 2 only. Dryness of the skin was noted from days 4 to 7.

-After four-hour exposure (four animals): Very slight or slight erythema (grade 1 or 2) was observed up to day 3 (two animals) or 6. It was accompanied by slight or severe oedema (grade 2 or 4) for 24 hours in all animals.

-Mean scores over 24, 48 and 72 hours for individual animal were 1.3, 1.0 and 1.0 for erythema and 0.7 for oedema.

CONCLUSION

Under these experimental conditions, the test substance LUPEROX 231 (l,1-DI-(tertBUTYLPEROXY)- 3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Reference 2

Endpoint:

skin corrosion: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin irritation study does not need to be conducted because adequate data from an in vivo skin irritation study are available

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

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)

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

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 No. 70), 18 weeks (female No. 71), 20 weeks (female No. 72)
Body Weight Range (when treated): 3137 g (male No. 70), 2827 g (female No. 71), 2814 g (female No. 72)
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.

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.1 mL of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) 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):

7 (animal no. 70 and 72) or 10 days (animal no. 71), respectively

Number of animals or in vitro replicates:

3 (1 male and 2 females)

Details on study design:

Di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) 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 4-5.

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.

The eyes of the animals were examined one day prior to test item administration.

0.1 mL of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) 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 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.

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48 h

Score:

0.67

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

The instillation of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) 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 and slight ocular discharge was noted, although exclusively 1 hour after instillation. All effects were reversible and were no longer evident 7 days after treatment. 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.

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.

Interpretation of results:

other: not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Based upon the referred classification criteria (Regulation (EC) No 1272/2008), di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) is not classified with respect to eye irritation in rabbits.

Executive summary:

The primary eye irritation potential of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) 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 as well as 7 days (all animals) or 10 days (just one animal) 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, 0.67 and 0.00 for reddening and 0.00, 0.00 and 0.00 for chemosis, respectively.

The instillation of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) into the eye resulted in mild, early-onset and transient ocular changes, such as reddening and swelling of the conjunctivae, ocular discharge and reddening of the sclerae. These effects were reversible and were no longer evident 7 days after treatment. 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 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) is not classified with respect to eye irritation in rabbits.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD Guideline for Testing of Chemicals 437: Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants (September, 2009).

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals 437: Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants (September, 2009).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Amount / concentration applied:

1 mL of the neat liquid test item were applied onto 3 bovine corneas

Duration of treatment / exposure:

the corneas were exposed to the test item for 10 min; afterwards the corneas were incubated for further 2 hours

Details on study design:

the corneas were exposed to the test item for 10 min; afterwards the corneas were incubated for further 2 hours; after determination of the corneas opacity a fluorescein solution was applied onto the corneas; after further 90 minutes the amount of permeated fluorescein was determined photometrically in order to evaluate the test item's effect on the cornea's pemeability

Irritation parameter:

in vitro irritation score

Value:

0

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Irritant / corrosive response data:

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No. 6731-36-8) is not considered to be an eye irritant.

Results after 10 Minutes Incubation Time

Test Group	Opacity value = Difference (t130-t0) of Opacity		Permeability at 490 nm (OD490)		In vitroScore	Meanin vitroScore	Proposedin vitroIrritation Scale
		Mean		Mean
Negative Control	0	0.33	0.050	0.077	0.75	1.48	Non eye irritant
Negative Control	1		0.072		2.08
Negative Control	0		0.108		1.62
Positive Control	67.67*		1.6063*		91.76	94.18	Very severe eye irritant
Positive Control	66.67*		2.1213*		98.49
Positive Control	63.67*		1.9073*		92.28
Test Item	-1.33*		-0.0047*		0.00	0.00	Non eye irritant
Test Item	-0.33*		0.0083*		0.00
Test Item	-0.33*		-0.0067*		0.00

*corrected values

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: other: OECD Guideline for Testing of Chemicals 437: Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants (September, 2009).

Executive summary:

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No. 6731-36-8) is not considered to be an eye irritant.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation

Under these experimental conditions, the test substance LUPEROX 231 (l,I-DI-(tertBUTYLPEROXY)- 3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Eye Irritation

The instillation of di-tert-butyl 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) into the eye resulted in mild, early-onset and transient ocular changes, such as reddening and swelling of the conjunctivae, ocular discharge and reddening of the sclerae. These effects were reversible and were no longer evident 7 days after treatment. 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 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) is not classified with respect to eye irritation in rabbits.

Bovine Corneal Opacity

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No. 6731-36-8) is not considered to be an eye irritant.

Justification for selection of skin irritation / corrosion endpoint:

Apparently well conducted GLP study.

Justification for selection of eye irritation endpoint:

Apparently well conducted GLP study.

Justification for classification or non-classification

Skin Irritation

The test substance LUPEROX 231 (l,I-DI-(tertBUTYLPEROXY)- 3,3,5-TRIMETHYLCYCLOHEXANE) was considered non-irritant when administered by cutaneous route in rabbits.

Eye Irritation

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 3,3,5-trimethylcyclohexylidene diperoxide (CAS# 6731-36-8) is not classified with respect to eye irritation in rabbits.

Bovine Corneal Opacity

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane (CAS No. 6731-36-8) is not considered to be an eye irritant.