Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

The skin-sensitization potential of the test substance DCBS was evaluated in a Guinea pig maximization test and found negative. In a read across approach with DCBS, CBS, TBS and MBS similarities in toxicity parameters like oral and dermal acute toxicity and repeated dose toxicity (for more details see chapter repeated dose toxicity) were noted. The structure analogues CBS, TBBS and MBS induced positive skin reactions in human volunteers and were classified as skin sensitizing. In the light of negative responses in guinea pig tests of CBS and TBBS but positive findings in well documented human studies for both substances, a skin sensitizing potential of DCBS in humans is suggested.

No cases of skin sensitisation related with professional activities derived from contact with Sulfenamides and Thiazoles were reported from several companies. The applied RMMs (Risk Management Measures) and OCs (Operational conditions) in these factories correspond with the moderate hazard band, which applies for substances having a moderate hazard profile i.e. moderate sensitisers, categorized as Skin Sens. 1 B (H 317). On a weight-of-evidence consideration, classification with Skin Sens.1B (H317: May cause an allergic skin reaction) is justified (please see Chapter 13 for the full reports).

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study, comparable to guideline study
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
The GPMT was reported in the year 1985. At this time pount no reliable guideline for a LLNA was available.
Species:
guinea pig
Strain:
Hartley
Sex:
female
Route:
intradermal
Vehicle:
peanut oil
Concentration / amount:
induction phase (intradermal injection): 5% , topical: 25 %; challenge phase: (topical application): 25 % in petrolatum
Route:
epicutaneous, occlusive
Vehicle:
peanut oil
Concentration / amount:
induction phase (intradermal injection): 5% , topical: 25 %; challenge phase: (topical application): 25 % in petrolatum
No. of animals per dose:
20 females treatment group, 10 females solvent control, 10 females postive control
Positive control substance(s):
yes
Positive control substance(s):
other: Positive control: 2,4 -dinitrochlorobenzene
Reading:
rechallenge
Hours after challenge:
672
Group:
positive control
Dose level:
no data
No. with + reactions:
10
Total no. in group:
10
Reading:
rechallenge
Hours after challenge:
672
Group:
negative control
Dose level:
no data
No. with + reactions:
0
Total no. in group:
10
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
25 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
few animals with very slight to slight erythema (grad 0.5 to 1) very similar to negative control
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: few animals with very slight to slight erythema (grad 0.5 to 1) very similar to negative control.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
25 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
few animals with very slight to slight erythema (grad 0.5 to 1) very similar to negative control
Remarks on result:
other: see Remark
Remarks:
Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: few animals with very slight to slight erythema (grad 0.5 to 1) very similar to negative control.

Mortality and overt signs of toxicity:

none of the guinea pig died. All guinea pigs appeard normal throughout the study period with the exception of the 3/10 animals of the positive control, 1/20 treatment group ( scanty stool).

Body weight gain:

1/10 guinea pigs in the positive control group exhibited a 12% weight loss at termination from its initial body weight. No other remarkable changes or differences were observed in body weights.

Dermal observations:

All positive control animal exhibited a positive reaction (erythema score 24, 48 h: 1.9, 1.9).

A few guinea pigs in both negative control and test article groups exhibited low level irritation at the test article application sites. One animal of the control group and one animal in the test group were also noted for very slight irritation at the vehicle control site. The irritation consist of grades 0.5 and 1 erythema. A few animal were also noted for grade 1 edema. The indicence of irritation was the same between the two groups and the group average irritation scores were very comparable (average score 24 h: 0.15 treatment group vs. 0.15 negative control; 48 h: 0.13 vs. 0.15)

No irritation was observed at the vehicle site on any animal either group at rechallenge. Three guinea pigs in the test group exhibited slightly patchy to slight erythema at the test article site. Only one of the guinea pigs exhibited a grade 1 erythema and none of the animals were noted for edema.

Interpretation of results:
GHS criteria not met
Remarks:
Migrated information
Executive summary:

The skin-sensitization potential of the test substance DCBS was evaluated in a Guinea pig maximization test. The intradermal induction was performed using 5% test substance, and the topical induction was performed with 25% test substance concentration. The challenge using 25 % test substance formulation led to very slight skin reactions in the treatment group comparable to the negative control group (erythema average score 24 h: 0.15 treatment group, 0.15 negative control; 48 h: 0.13 treatment group, 0.15 negative control), whereas all positive control animal exhibited a positive reaction (erythema average score 24, 48 h: 1.9, 1.9). In summary, by comparing the results in the treatment group and in the negative control group the test substance did not show a skin-sensitization potential (Monsanto Co. 1985).

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

Non human data

The skin-sensitization potential of the test substance DCBS was evaluated in a Guinea pig maximization test. The intradermal induction was performed using 5% test substance, and the topical induction was performed with 25% test substance concentration. The challenge using 25 % test substance formulation led to very slight skin reactions in the treatment group similar to the negative control group (erythema average score 24 h: 0.15 treatment group, 0.15 negative control; 48 h: 0.13 treatment group, 0.15 negative control); whereas all positive control animal exhibited a positive reaction (erythema average score 24, 48 h: 1.9, 1.9). In summary, by comparing the results in the treatment group and in the negative control group the test substance did not show a skin-sensitization potential (Monsanto Co. 1985).

Human data

In several well documented Repeated Insult Patch tests with human volunteers a skin sensitizing potential of the structure analogues CBS, TBBS and MBS were noted. The substances CBS, TBBS and MBS were classified as skin sensitizer in humans. In a read across approach, where physicochemical data and toxicological findings of DCBS, CBS, TBBS and MBS were compared, consistencies in acute toxicity (oral and dermal), skin and eye-irritation, as well as repeated dose toxicity were found. However, CBS and TBBS showed no positive response in Buehler assays with guinea pigs but positive responses in humans. In light of this observation, it is discussed if the negative response of DCBS noted in a guinea pig maximization test reflects the human situation. Based on the read across approach with data from human volunteers treated with the CBS, TBBS or MBS a skin sensitizing potential of DCBS in humans is suggested.


Justification for classification or non-classification

Based on a read across approach with the structure analogues CBS, TBBS and MBS, a skin sensitizing potential of DCBS in humans is suggested; a classification of DCBS as skin sensitizer according to the classification criteria of regulation no. 1272/2008 (GHS) is recommended.

DCBS was negative in a guinea pig maximization assay (Monsanto Co. 1985). In a read across approach (please see Chapter 13 for details), where physicochemical data and toxicological findings of DCBS, CBS, TBBS and MBS were compared; consistencies in acute toxicity (oral and dermal), skin and eye-irritation, as well as in repeated dose toxicity were found. The substances CBS, TBBS and MBS were all classified as skin sensitizer in humans. Based on this finding and on the similarities noted in toxicity parameter a moderate skin sensitizing potential of DCBS in humans is suggested (Skin Sens. 1B).