tert-butyl hydroperoxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP standards

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: 40 CFR 163.81-5

Deviations:

no

Principles of method if other than guideline:

Draize method: Test animals have approximately 10% hair shaved off their backs. The left side was abraded with a 20 gauge hypodermic needle, the right side remained intact. On each of the test animals, four areas were exposed to an aliquot of the product. Aliquots were applied to an anterior and posterior site on the abraded and intact skin under four layers of gauze patches. The patches were covered with a rubber dental dam and then secured with adhesive tape. After 24 hours, the tape, rubber dental dam and patches were removed. Readings were recorded at 24 and 72 hours.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

tert-butyl hydroperoxide

EC Number:

200-915-7

EC Name:

tert-butyl hydroperoxide

Cas Number:

75-91-2

Molecular formula:

C4H10O2

IUPAC Name:

2-methylpropane-2-peroxol

Details on test material:

Aqueous solution containing TBHP at ca. 70 wt%
Tertiary Butyl Hydroperoxide (70%)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Marland Farms, Hewitt, New Jersey
- Age at study initiation: n/a
- Weight at study initiation: 1.9 - 3.1 kg
- Housing: Individual, Suspended wire cages
- Diet (e.g. ad libitum): Wayne rabbit ration (ad libitum)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 11 days

Test system

Type of coverage:

occlusive

Preparation of test site:

other: all shaved, some abraded some not

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): undiluted test material (i.e. 70% TBHP)

Duration of treatment / exposure:

24 hour exposure

Observation period:

72 hours

Number of animals:

6 (3 male and 3 female)

Details on study design:

TEST SITE
- Area of exposure: Anterior and posterior sites on the back
- % coverage: 10
- Type of wrap if used: 4 layers of gauze patches covered by a rubber dental dam and secured with adhesive tape.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): Treated areas were wiped free of any compound.
- Time after start of exposure: 24 h

Results and discussion

In vivo

Results

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: using 24h & 72h results

Score:

4.39

Reversibility:

not reversible

Remarks:

determined after 14 days post treatment

Remarks on result:

other: See table 1 for further details

Other effects:

3 of the 6 animals died within 24 hours following test substance administration; all rabbits were cyanotic and depressed within 1 hour of administration; At 24 hours or death, all rabbits showed moderate to severe oedema (3.5 for intact and abraded) and 4 had mild to moderate erythema (0.33 and 0.84 for intact and abraded); at 72 hours, a mild to moderate erythema was seen in 2 of the 3 survivors (1.67 for intact and abraded) and slight oedema was seen in one and severe oedema in the remaining 2 survivors (3 for intact and abraded); 14 days post dosing 2 of the remaining rabbits had skin described as "parchment-like", appeared necrotic and was beginning to slough.

Any other information on results incl. tables

Table 1: Observed effects

				Observed Effects
				Intact Skin				Abraded Skin
				Erythema		Oedema		Erythema		Oedema
Rabbit No.	Sex	Weight		24h	72h	24h	72h	24h	72h	24h	72h
1	F	2.55		0	- (1)	3	-	2	-	3	-
2	F	3.10		0	2	4	4	1	2	4	4
3	F	1.90		0	- (2)	4	-	0	-	4	-
4	M	2.15		1	3	4	4	1	3	4	4
5	M	2.00		0	- (3)	4	-	0	-	4	-
6	M	2.50		1	0	2	1	1	0	2	1
Mean				0.33	1.67	3.5	3	0.84	1.67	3.5	3
Mean 24 And 72h				1.00		3.25		1.26		3.25
				Mean Intact Score = 2.13				Mean Abraded Score = 2.26

Primary irritation index = 4.39

(1) Dead 24 hours post dosing

(2) Dead 4:35 hours post dosing

(3) Dead 5 hours post dosing

Applicant's summary and conclusion

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Aq. TBHP-70 is considered a severe dermal irritant which should be classified as corrosive. It follows that TBHP itself must be considered corrosive.

Executive summary:

TBHP (aqueous solution as tested) is considered a severe dermal irritant which should be classified as corrosive category 1C under Regulation 1272/2008, CLP.