Registration Dossier
Registration Dossier
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EC number: 234-042-8 | CAS number: 10508-09-5
Endpoint summary
Administrative data
Description of key information
The delayed contact hypersensivity of di-tert-amyl peroxide was evaluated in a Guindea Pig Maximisation Test (GPMT) according to OECD 406 guideline (Ollivier, 2006). The induction phase has been realized both by intradermal route on day (25 % in corn oil) and by cutaneous route on day 8 (undiluted) in 2 groups of guinea pigs: 5 males and 5 females for control group and 10 males and 10 females for treated group. The challenge phase was realized on day 22 by cutaneous application of di-tert-amyl peroxide at 50 % in acetone; the cutaneous reactions were scored 24 and 48 hours after the challenge phase. As equivocal cutaneous reactions were noted after the first challenge, a second challenge application was performed on day 39. The test item was applied at the concentration of 10% (w/w) in acetone to the median left flank and at the concentration of 5% (w/w) in acetone to the median right flank of the animals of both groups, under the same experimental conditions as for the first challenge application. After the first challenge application, a discrete erythema was observed in 3/10 animals of the control group at the 24-hour reading. At the 48-hour reading, a discrete or moderate erythema was noted in 7/10 animals. Dryness of the skin was also recorded in 2/10 animals at the 24-hour reading. In the treated group, a discrete or moderate erythema was noted in 11/20 and 17/20 animals at the 24 and 48-hour readings, respectively. Dryness of the skin was also recorded in 3/20 and 2/20 animals at the 24 and 48-hour readings, respectively. After the second challenge application, no relevant cutaneous reactions were noted. As the cutaneous reactions observed after the first challenge application were of similar incidence and severity in the control and treated groups and as no relevant cutaneous reactions were recorded after the second challenge application at the concentrations of 5 and 10%, the test item at the concentration of 10% should not be considered as a skin sensitizer.
Key value for chemical safety assessment
Skin sensitisation
Link to relevant study records
- Endpoint:
- skin sensitisation: in vivo (non-LLNA)
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 2006
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- other: GLP guideline study, Klimisch 1a
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 406 (Skin Sensitisation)
- Version / remarks:
- 17th July 1992
- GLP compliance:
- yes (incl. QA statement)
- Type of study:
- guinea pig maximisation test
- Justification for non-LLNA method:
- The study was performed before the implementation of the REACH regulation
- Species:
- guinea pig
- Strain:
- Hartley
- Sex:
- male/female
- Details on test animals and environmental conditions:
- - Breeder: Charles River Laboratories France, L’Arbresle, France.
- Diet and water: ad libitum
- Age/weight: on day 1, the animals of the main test were 1-2 months old and had a mean body weight ± standard deviation of 345 ± 12 g for the males and 343 ± 15 g for the females.
- Acclimation: at least 5 days before the beginning of the study.
- Identification: by individual ear-tattoo.
- Temperature: 22 ± 2°C
- Relative humidity: 30 to 70%
-Light/dark cycle: 12 h/12 h
- Ventilation: approximately 12 cycles/hour of filtered, non-recycled air. - Route:
- intradermal
- Vehicle:
- other: corn oil, for intradermal induction, acetone for topical induction
- Concentration / amount:
- 1/INDUCTION
- Intradermal: 25 %
- Cutaneous: 100 %
2/ CHALLENGE
- first challenge: 50 %
- re challenge: 5 % and 10 % - Route:
- intradermal and epicutaneous
- Vehicle:
- other: corn oil, for intradermal induction, acetone for topical induction
- Concentration / amount:
- 1/INDUCTION
- Intradermal: 25 %
- Cutaneous: 100 %
2/ CHALLENGE
- first challenge: 50 %
- re challenge: 5 % and 10 % - No. of animals per dose:
- 15
- Details on study design:
- 1/ INDUCTION
Intradermal injections:
Three injections of 0.1 mL were made into each side of this interscapular region (i.e. three pairs
of sites), as follows:
Treated group
- FCA at 50% (v/v) in 0.9% NaCl (anterior site)
- test item at 25% (w/w) in corn oil (middle site)
- test item at 25% (w/w) in the mixture FCA/0.9% NaCl (50/50) (posterior site)
Control group
- FCA at 50% (v/v) in 0.9% NaCl (anterior site)
- corn oil (middle site)
- vehicle at 50% (w/v) in a mixture FCA/0.9% NaCl (50/50) (posterior site)
Cutaneous application:
As the test item was shown to be irritant during the preliminary test, a topical application of sodium lauryl sulfate was not necessary on day 7. On day 8, a pad of filter paper (approximately 8 cm2) was fully-loaded with the undiluted test item and was then applied to the interscapular region of the animals of the treated group. The animals of the control group received an application of the vehicle alone under the same
experimental conditions.
2/CHALLENGE
First challenge application: on day 22, the animals of treated and control groups received an application of the test item and
vehicle at the concentration of 50% (w/w)
The chambers were held in contact with the skin for 24 hours by means of an adhesive anallergenic waterproof plaster.
As equivocal cutaneous reactions were noted, a second challenge application was performed after a rest period of 16 days.
Second challenge application
On day 39, the animals of treated and control groups received an application of the test item at the concentration of 10% (w/w) to the median left flank and at the concentration of 5% (w/w) to the median right flank, under the same experimental conditions as for the first challenge
application - Positive control substance(s):
- yes
- Remarks:
- Mercaptobenzothiazole
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- negative control
- Dose level:
- 50%
- No. with + reactions:
- 3
- Total no. in group:
- 10
- Clinical observations:
- discrete erythema
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- test chemical
- Dose level:
- 50%
- No. with + reactions:
- 11
- Total no. in group:
- 20
- Clinical observations:
- discrete or moderate erythema
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- negative control
- Dose level:
- 50%
- No. with + reactions:
- 7
- Total no. in group:
- 10
- Clinical observations:
- discrete or moderate erythema
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- test chemical
- Dose level:
- 50%
- No. with + reactions:
- 17
- Total no. in group:
- 20
- Clinical observations:
- discrete or moderate erythema
- Reading:
- rechallenge
- Hours after challenge:
- 24
- Group:
- other: negative and treated groups
- Dose level:
- 5 or 10 %
- No. with + reactions:
- 0
- Total no. in group:
- 20
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- positive control
- Dose level:
- 1%
- No. with + reactions:
- 8
- Total no. in group:
- 10
- Remarks on result:
- positive indication of skin sensitisation
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- Under these experimental conditions and according to the maximization method of Magnusson and Kligman, di-tert-amyl peroxide at the concentration of 10% did not induce delayed contact hypersensitivity in guinea pigs.
- Executive summary:
The delayed contact hypersensivity of di-tert-amyl peroxide was evaluated in Guinea pigs according to OECD N°406 guideline (July 17th1992 - Magnusson and Kligman test).
The induction phase has been realized both by intradermal route on day (25 % in corn oil) and by cutaneous route on day 8 (undiluted) in 2 groups of guinea pigs: 5 males and 5 females for control group and 10 males and 10 females for treated group. The challenge phase was realized on day 22 by cutaneous application of di-tert-amyl peroxide at 50 % in acetone; the cutaneous reactions were scored 24 and 48 hours after the challenge phase.
As equivocal cutaneous reactions were noted after the first challenge, a second challenge application was performed on day 39. The test item was applied at the concentration of 10% (w/w) in acetone to the median left flank and at the concentration of 5% (w/w) in acetone to the median right flank of the animals of both groups, under the same experimental conditions as for the first challenge application.
No clinical signs and no deaths were noted during the study.
After the first challenge application, a discrete erythema was observed in 3/10 animals of the control group at the 24-hour reading. At the 48-hour reading, a discrete or moderate erythema was noted in 7/10 animals. Dryness of the skin was also recorded in 2/10 animals at the 24-hour reading.
In the treated group, a discrete or moderate erythema was noted in 11/20 and 17/20 animals at the 24 and 48-hour readings, respectively. Dryness of the skin was also recorded in 3/20 and 2/20 animals at the 24 and 48-hour readings, respectively.
After the second challenge application, no relevant cutaneous reactions were noted. As the cutaneous reactions observed after the first challenge application were of similar incidence and severity in the control and treated groups and as no relevant cutaneous reactions were recorded after the second challenge application at the concentrations of 5 and 10%, the test item at the concentration of 10% should not be considered as a skin sensitizer.
Reference
First challenge application
Scoring of skin reactions was as follows:
Control group
Sex Animal 24 hours 48 hours number LF RF LF RF
Male 71 0 1 0 2
72 0 1 0 1
73 0 0 0 0
74 0 0 0 1
75 0 1 0 2
Female 86 0 0/S 0 2
87 0 0/S 0 1
88 0 0 0 1
89 0 0 0 0
90 0 0 0 0
Treated group
Sex Animal 24hours 48hours
number LF RF LF RF
Male 76 0 0/S 0 2
77 0 2 0 2
78 0 1 0 1
79 0 1 0 1
80 0 0/S 0 1/S
81 0 1 0 1
82 0 1 0 2
83 0 1 0 2
84 0 1 0 1/S
85 0 2 0 1
Female 91 0 0/S 0 1
92 0 2 0 1
93 0 0 0 1
94 0 0 0 0
95 0 0 0 0
96 0 1 0 1
97 0 0 0 1
98 0 0 0 1
99 0 1 0 1
100 0 0 0 0
LF:left flank(vehicle)
RF:right flank (test item at the concentration of 50% (w/w)) S :dryness of the skin
Second challenge application
Scoring of skin reactions was as follows:
Control group
Sex Animal beforetreatment 24hours 48hours number LF RF LF RF LF RF
Male 71 0 0 0 0 0 0
72 0 0 1 0 1/S 0
73 0 0 0 0 0 0
74 0 0 0 1 0 0
75 0 0 0 0 0 0
Female 86 0 0 0 0 0 0
87 0 0 0 0 0 0
88 0 0 0 0 0 0
89 0 0 0 0 0 0
90 0 0 0 0 0/S 0
LF:left flank (test itemat the concentrationof 10% (w/w)) RF: right flank (test item at the concentration of 5%)
S :dryness of the skin
Treated group
Sex Animal before treatment 24 hours 48 hours number LF RF LF RF LF RF
Male |
76 |
0 |
0 |
0 |
0 |
0 |
0 |
|
77 |
0 |
0 |
0 |
1 |
0 |
0 |
|
78 |
0 |
0 |
0 |
0 |
0 |
0 |
|
79 |
0 |
0 |
0 |
0 |
0 |
0/S |
|
80 |
0 |
0 |
0 |
0 |
0/S |
0 |
|
81 |
0 |
0 |
0 |
0 |
0 |
0 |
|
82 |
0 |
0 |
0 |
0 |
0 |
0 |
|
83 |
0 |
0 |
0 |
0 |
0 |
0 |
|
84 |
0 |
0 |
0 |
0 |
0 |
0 |
|
85 |
0 |
0 |
0 |
0 |
0 |
0 |
Female |
91 |
0 |
0 |
0 |
0 |
0 |
0 |
|
92 |
0 |
0 |
0 |
0 |
0 |
0 |
|
93 |
0 |
0 |
0 |
0 |
0 |
0 |
|
94 |
0 |
0 |
0 |
0 |
0 |
0 |
|
95 |
0 |
0 |
0 |
0 |
0 |
0 |
|
96 |
0 |
0 |
0 |
0 |
0 |
0 |
|
97 |
0 |
0 |
0 |
0/S |
0 |
0/S |
|
98 |
0 |
0 |
0 |
0 |
0 |
0 |
|
99 |
0 |
0 |
0 |
0 |
0 |
0 |
|
100 |
0 |
0 |
0 |
0 |
0 |
0 |
LF: left flank (test item at the concentration of 10% (w/w)) RF: right flank (test item at the concentration of 5%)
S :dryness of the skin
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not sensitising)
Respiratory sensitisation
Endpoint conclusion
- Endpoint conclusion:
- no study available
Justification for classification or non-classification
According to EU Regulation (EC) N0. 1272/2008 (CLP), di-tert amyl peroxide is not classified for skin sensitisation.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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