Di-tert-butyl 1,1,4,4-tetramethyltetramethylene diperoxide

Endpoint summary

Description of key information

1 TEST: With 4 hours of exposure, slight irritation, with scores not meeting the criteria for classification.  Desquamation was also noted which had not resolved in all animals by day 14.

2 TEST: With 24 hours of exposure,  the substance caused severe skin irritation. Its dermal effects observed after 24 hours generaly consisted of well-defined erythema, slight to distinct ischemia and very slight to slight edema. The dermal effects observed after 72 hours generally consisted of slight to distinct incrustation and very slight edema.

Based on these results, the test substance needs to be labelled for skin irritation Cat 2 according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

 

Slight conjunctival effects were noted in two eye irritation studies; however, they were not severe enough to warrant classification. Based on these results, the test substance does not need to be labelled for eye irritation according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

 

A study for respiratory irritation is not available as inhalation is not a relevant route of exposure for this substance.

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:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study performed according to established principles and published methods which were current at the time but not OECD guideline. There is no CoA for the test material; it is described only by trade name, lot number and physical appearance.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

see below

Principles of method if other than guideline:

- Exposure period was 24 hours under occlusion, not 4 hours under semi-occlusion.
- The protocol states that animals may be used for 1 - 4 test substances, although it cannot be determined whether or not that occurred in this study.
- The observation period was 72 hours not 14 days.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Twelve health adult New Zealand White albino rabbits are used for 1-4 substances.

Type of coverage:

occlusive

Preparation of test site:

other: one part shaved only, one part shaved and abraded

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 ml

Duration of treatment / exposure:

24 hours

Observation period:

72 hours following patch removal

Number of animals:

Twelve (six intact, six abraded)

Details on study design:

Twenty four hours prior to applying the materials, the hair is removed from the backs of the animals with an electric clipper in such a way as to avoid abrasions. 0.5 ml of the test substance is brought on the intact or abraded skin under a surgical patch measuring 1 inch x 1 inch. The patches are fixed to the application site by means of adhesive tape and the entire trunk of the rabbits is wrapped with an impervious material to maintain the test patches in position and to retard evaporation of volatile substances.

Six rabbits are treated on the intact skin, the other six on the abraded skin. The abrasions are minor incisions through the stratum corneum, but not sufficiently deep to disturb the derma or to produce bleeding.

After an exposure period of 24 hours the patches and the material applied are removed and the resulting skin reactions are evaluated by the method of Draize. A second reading is made 48 hours later (72 hours after application).

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 hours

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: an additional 48 hours

Remarks on result:

other: intact skin; all scores 4 out of 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 hours

Score:

4

Max. score:

4

Reversibility:

other: last observation for this study

Remarks on result:

other: intact skin; all scores 4 out of 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 hours

Score:

2

Max. score:

2

Reversibility:

not fully reversible within: an additional 48 hours

Remarks on result:

other: intact skin; all scores 2 out of 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 hours

Score:

1

Max. score:

1

Reversibility:

other: last observation for this study

Remarks on result:

other: intact skin; all scores 1 out of 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 hours

Score:

3.6

Max. score:

4

Reversibility:

not fully reversible within: an additional 48 hours

Remarks on result:

other: abraded skin; for erythema five animals had score 4 out of 4, one animals had score 2 out of 4

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 hours

Score:

3.5

Max. score:

4

Reversibility:

other: last observation for this study

Remarks on result:

other: abraded skin; five animals had score 4 out of 4, one animal had score 1 out of 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 hours

Score:

1.3

Max. score:

2

Reversibility:

not fully reversible within: an additional 48 hours

Remarks on result:

other: abraded skin; two animals had score 2 out of 4, four animals had score 1 out of 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 hours

Score:

0.7

Max. score:

1

Reversibility:

other: last observation for this study

Remarks on result:

other: abraded skin; four animals had score 1 out of 4, two animals had score 0 out of 4

Irritant / corrosive response data:

On the basis of the present results it can be concluded that the substance is a severe primary skin irritant.

Other effects:

None reported.

Its dermal effects observed after 24 hours generaly consisted of well-defined erythema, slight to distinct ischemia and very slight to slight edema. The dermal effects observed after 72 hours generally consisted of slight to distinct incrustation and very slight edema. There were no distinct differences between skin reactions of the intact skin and those of the abraded skin.

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

On the basis of the present results it can be concluded that the substance is a severe primary skin irritant. Mean value of > 2.3 - < 4.0 for erythema in all animals from gradings at 24, 48 and 72 hours after patch removal. Reversibilty of these effects cannot be judged from this study since the observations stopped after 72 hours. However corrosion was not observed and the animals were exposed for 24 hours instead of 4 hours.

Based on these results, the test substance needs to be labelled for skin irritation Cat 2 according to
the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the
United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on
classification, labelling and packaging of items and mixtures (including all amendments).

Executive summary:

Primary irritation to the skin is measured by a patch-test technique on the abraded and intact skin of albino rabbits. It caused severe skin irritation. Its dermal effects observed after 24 hours generaly consisted of well-defined erythema, slight to distinct ischemia and very slight to slight edema. The dermal effects observed after 72 hours generally consisted of slight to distinct incrustation and very slight edema. There were no distinct differences between skin reactions of the intact skin and those of the abraded skin.

On the basis of the present resutls it can be concluded that the substance is a severe primary skin irritant.

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

29 September 1994 - 2 November 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well-conducted and documented study performed under GLP; however, no CoA for the test material is included in the report.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Myrtle's Rabbitry, Thompson Station, TN.
- Age at study initiation: adult
- Weight at study initiation: 2.0 to 3.5 kg
- Housing: The animals were housed individually in suspended stainless steel cages. All housing and care were based on the standards recommended by the Guide for the Care and Use of Laboratory Animals
- Diet (e.g. ad libitum): Purina Certified Rabbit Chow #5322 was provided ad libitum to the animals throughout the study. The lot number and expiration date of each batch of diet used during the study were recorded. The feed was analyzed by the supplier for nutritional components and environmental contaminants. Dietary limitations for various environmental contaminants, including heavy metals, pesticides, polychlorinated biphenyls and total aflatoxin are set by the manufacturer. Within these limits, contaminants which may have been present were not expected to compromise the purpose of this study. Results of the dietary analyses (Certificates of Analysis) are provided by the manufacturer for each lot of diet. These are maintained by SLS.
- Water (e.g. ad libitum): Municipal tap water treated by reverse osmosis or deionization (back-up system) was available to the animals ad libitum throughout the study. The purified water was supplied by an automatic watering system. Monitoring of the drinking water for contaminants was conducted by SLS and the records are available for inspection. Within generally accepted limits, contaminants which may have been present were not expected to compromise the purpose of this study.
- Acclimation period: Upon receipt, animals were examined, identified with plastic ear tags and then quarantined for a minimum of five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):± 19-21
- Humidity (%): 46-64
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: 29 September 1994 - 2 November 1994

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

4 hours

Observation period:

Animals were examined for signs of erythema and edema and the responses scored at approximately 1, 24, 48 and 72 hours and up to 14 days after patch removal

Number of animals:

3 males and 3 females

Details on study design:

TEST SITE
- Area of exposure: 1" X 1" square 4 ply gauze patch
- % coverage:-
- Type of wrap if used: The test article was administered under the gauze patch. The gauze patch was held in contact with the skin at the cut edges with a non-irritating tape. Removal and ingestion of the test article was prevented by placing an elastic wrap over the trunk and test area (semi-occlusive binding). The elastic wrap was then further secured with adhesive tape around the trunk at the cranial and caudal ends.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test article was removed using gauze moistened with distilled water.
- Time after start of exposure: immediatly after the 4 hour exposure.

SCORING SYSTEM: Draize

Irritation parameter:

erythema score

Basis:

mean

Remarks:

all

Time point:

other: 24-48-72 hours

Score:

1.22

Max. score:

2

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: in 5/6 animals desquamation was observed

Irritation parameter:

edema score

Basis:

mean

Remarks:

all

Time point:

other: 24-48-72 hours

Score:

0.94

Max. score:

2

Reversibility:

fully reversible within: 14 days

Remarks on result:

other: in 5/6 animals desquamation was observed

Irritant / corrosive response data:

Exposure to the test article produced very slight to well-defined erythema and very slight to slight edema on 6/6 test sites at the 1 hour scoring interval, the 4-hour interval was not evaluated.
The dermal irritation resolved completely in all animals by study day 14. Additional dermal findings noted during the period included desquamation in 5 of the 6 test animals.

Summary of dermal lesions

 

no.	Effect	Hour	Days after application						Mean score erythema 24/48/72 h *	Mean score oedema 24/48/72 h *
		1	1	2	3	7	10	14
51403/M	Erythema/ eschar Oedema	1 1	1 1	1 1	1 0	1** 0	2 1	0** 0	1	0.66
51411/F	Erythema/ eschar Oedema	1 1	2 1	1 1	1 0	0 0	- -	- -	1.33	0.66
51387/M	Erythema/ eschar Oedema	2 1	2 1	1 1	0 1	0** 0	- -	- -	1	1
51388/M	Erythema/ eschar Oedema	2 2	2 1	1 1	1 1	1 0	1** 0	0** 0	1.33	1
51427/F	Erythema/ eschar Oedema	2 1	2 1	1 1	1 1	1** 1	2 1	0** 0	1.33	1
51430/F	Erythema/ eschar Oedema	2 2	2 2	2 1	1 1	1 1	2 1	0** 0	1.66	1.33
Mean Group									1.22	0.94

* Mean score based on 24, 48 and 72 h after application

**desquamation

 

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Based on these results, the test substance needs to be labelled for skin irritation Cat 2 according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the
United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on
classification, labelling and packaging of items and mixtures (including all amendments).

Executive summary:

The potential irritant and/or corrosive effects of the substance were evaluated on the skin of New Zealand White rabbits. Each of six rabbits received a 0.5 ml dose of the test article as a single dermal application. The dose was held in contact with the skin under a semi-occlusive binder for an exposure period of four hours. Following the exposure period, the binder was removed and the remaining test article was wiped from the skin using gauze moistened with distilled water. Test sites were subsequently examined and scored for dermal irritation for up to 14 days following patch removal. Exposure to the test article produced very slight to well-defined erythema and very slight to slight edema on 6/6 test sites at the 1 hour scoring interval. The dermal irritation resolved completely in all animals by study day 14. Additional dermal findings noted during the period included desquamation, which was noted on 5/6 test sites. Under the conditions of this test and according to established principles and criteria at the time the study was conducted the substance was considered to be an irritant to the skin of the rabbit.

Reference 3

Endpoint:

skin irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (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:

29 September 1994 - 27 October 1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well-conducted and documented study performed under GLP; however, no CoA for the test material is included in the report.

Qualifier:

according to guideline

Guideline:

EPA OTS 798.4500 (Acute Eye Irritation)

Deviations:

yes

Remarks:

One mortality check was not conducted and one was conducted but not documented. However, no mortality occurred during the study and the occurences are considered to have had no apparent impact on the outcome of the study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Adult, New Zealand White rabbits were received at SLS from Myrtle's Rabbitry, Thompson Station, TN. Upon receipt, plastic ear tags displaing unique identification numbers were used to individually identify the animals. Cage cards displaying at least the study number, animal number and sex were affixed to each cage. The animals were housed individually in suspsended stainles steel cages. All housing and care were based on the standards recommended by the Guide for the Care and Use of Laboratory Animals.

The animal room temperature and relative humidity ranges were 68 - 70 °F and 46 - 59%, respectively. Environmental control equipment was monitored and adjusted as necessary to minimize fluctuations in the animal room environment. Light timers were set to maintain a 12-hour light/12-hour dark cycle. There were ten to twelve air changes in the animal room per hour. the animal room temperature and relative humidity were recorded a minimum of once daily.

Purina Certified Rabbit chow #5322 was provided ad libitum to the animals throughout the study. the lot number and expiration date of each batch of diet used during the study were recorded. The feed was analyzed by the supplier for nutritional components and environmental contaminants. Dietary limitation for various environmental contaminants, including heavy metals. pesticides, polychlorinated biphenyls and total aflatoxin are set by the manufacturer. Within these limits, contaminants which may have been present were not expected to compromise the purpose of this study. Results of the dietary analyses (Certificates of Analysis) are provided by the manufacturer for each lot of diet. These are maintained by SLS.

Municipal tap water treated by reverse osmosis or deionization (back-up system) was available to the animals ad libitum throughout the study. The purified water was supplied by an automatic watering system. Monitoring of the drinking water for contaminants was conducted by SLS and the records are available for inspection. Within generally accepted limits, contaminants which may have been present were not expected to compromise the purpose of this study.

Upon receipt, animals were examined, identified with plastic ear tags and then quarantined for a minimum of five days. The animals chosen for study use were arbitrarily selected from healthy stock animals to avoid potential bias. All animals received a detailed pretest observation prior to dosing. Only healthy animals were chosen for study use. Females were nulliparous and nonpregnant.

Vehicle:

unchanged (no vehicle)

Controls:

other:

Amount / concentration applied:

0.1 ml

Duration of treatment / exposure:

Once

Observation period (in vivo):

The eyes were macroscopically examined with the aid of an auxiliary light source for signs of irritation at 1, 24, 48 and 72 hours after dosing according to the Ocular Grading System presented in Appendix B which is based on Draize. Following macroscopic observations at the 24 hour scoring interval, the fluorescein examination procedure was repeated on all test and control eyes and any residual test article was gently rinsed from the eye at this time (if possible) using 0.9% physiological saline. If positive fluorescein dye retention was noted at 24 hours, a fluorescein exam was conducted on the affected eyes at each subsequent interval until a negative response was obtained.

Number of animals or in vitro replicates:

six

Details on study design:

The test article was instilled into the conjunctival sac of the right eye of each animals after gently pulling the lower lid away from the eye. Following instillation, the eyelids were gently heald together for approximately one second in order to limit test article loss and the animal was returned to its cage. The contralateral eye remained untreated to serve as a control.

Irritation parameter:

conjunctivae score

Remarks:

(redness + swelling + discharge) x 2

Basis:

mean

Remarks:

mean of all six animals

Time point:

other: 1 hour

Score:

5

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

conjunctivae score

Remarks:

(redness + swelling + discharge) x 2

Basis:

mean

Remarks:

mean of all six animals

Time point:

other: 24 hours

Score:

2.33

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

conjunctivae score

Remarks:

(redness + swelling + discharge) x 2

Basis:

mean

Remarks:

mean of all six animals

Time point:

other: 48 hours

Score:

0.33

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

conjunctivae score

Remarks:

(redness + swelling + discharge) x 2

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

0

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: all

Score:

0

Max. score:

0

Irritation parameter:

iris score

Basis:

mean

Time point:

other: all

Score:

0

Max. score:

0

Irritant / corrosive response data:

Exposure to the test article produced conjunctivitis (redness, swelling and/or discharge) in 6/6 test eyes at the 1 hour scoring interval. The conjunctival irritation resolved completely in all animals by the 72 hour scoring interval.
Normal background positive fluorescein dye retention was observed in 1/6 control eyes (stippling) at the 24 hour scoring interval. This finding was resolved by 48 hours and was not considered significant. No corneal opacityI iritis or conjunctivitis was observed in the control eyes.

Summary of ocular lesions

Anim. No.	Effect	Hours	Days after application					Mean score cornea Days 1/2/3	Mean score iritis Days 1/2/3	Mean score redness Days 1/2/3	Mean score chemosis Days 1/2/3
		1	1	2	3	7	14
51369/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 1	0 0 1 1 0	0 0 0 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0.33	0
51370/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 1	0 0 1 0 0	0 0 0 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0	0
51364/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 1	0 0 1 0 0	0 0 0 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0.33	0
51337/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 0	0 0 1 0 0	0 0 0 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0.33	0
51362/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 0	0 0 1 0 0	0 0 1 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0.66	0
51275/F	Cornea Iris Redness Chemosis Discharge	0 0 1 1 0	0 0 1 0 0	0 0 0 0 0	0 0 0 0 0	- - - - -	- - - - -	0	0	0.33	0
Mean all anim.								0	0	0.33	0

Interpretation of results:

GHS criteria not met

Conclusions:

Slight conjunctival effects were noted in this study; however, they were not severe enough to warrant classification.
Based on these results, the test substance does not have to be classified and has no obligatory labelling requirement for eye irritation according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2017) (including all amendments) and Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

Executive summary:

The potential eye irritant and/or corrosive effects of the substance were evaluated on New Zealand White rabbits. Each of six rabbits received a 0.1 ml dose of the test article in the conjunctival sac of the right eye. The conralateral eye of each animal remained untreated and served as a control. Test and control eyes were examined for signs of irritation for up to 72 hours following dosing.

Exposure to the test article produced conjunctivitis (redness, swelling and/or discharge) in 6/6 test eyes at the 1 hour scoring interval. The conjunctival irritation resolved completely in all animals by the 72 hour scoring interval.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

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

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

On the basis of the result from 2 studies it can be concluded that the substance is a severe primary skin irritant after 24 hour exposure under occlusion. Mean values of > 2.3 - < 4.0 for erythema in all animals from gradings at 24, 48 and 72 hours after patch removal. Reversibilty of these effects cannot be judged from this study since the observations stopped after 72 hours. However corrosion was not observed and the animals were exposed for 24 hours instead of 4 hours.

While the two available studies, conducted with 24 hours of exposure reported severe irritation, in the study conducted in accordance with current guideline, using a 4 hour exposure, the registered substance was slightly irritating to skin with desquamation noted which had not resolved by day 14.

Effects on skin irritation/corrosion: highly irritating

Justification for classification or non-classification

The registered substance was classified as a skin irritant based on a study conducted using severe exposure conditions (i.e. 24 -hour exposure occlusive). 

 

Slight conjunctival effects were noted in two eye irritation studies; however, they were not severe enough to warrant classification.

 

Data to conclude on respiratory irritation is not available.