Dimethylbis(oleoyloxy)stannane

Endpoint summary

Description of key information

Read-across to DMTE (Dimethyltin bis (2-ethylhexyl thioglycolate) CAS No. 57583-35-4)

Significant differences between the test group and the vehicle-treated controls were found with the test material. The compound therefore has a skin sensitising (contact allergenic) potential in albino guinea pigs.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

Read-across to structurally similar substance DMTE (Dimethyltin bis (2-ethylhexyl thioglycolate) CAS 57583 -35 -4), see attached justification.

Reason / purpose for cross-reference:

read-across source

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 mL at 0.1 %

No. with + reactions:

9

Total no. in group:

20

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.1 mL at 0.1 %

No. with + reactions:

20

Total no. in group:

20

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Composition/purity of the test substance not reported.

Reason / purpose for cross-reference:

other: read-across target

Qualifier:

according to guideline

Guideline:

other: Maurer et al, 1975

Deviations:

not specified

GLP compliance:

no

Type of study:

Maurer optimisation test

Justification for non-LLNA method:

The study was conducted prior to the LLNA becoming the preferred method.

Species:

guinea pig

Strain:

other: Pirbright white

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Ciba-Geigy
- Weight at study initiation: 400 to 450 g
- Housing: individually in Macrolon cages, type 3
- Diet (e.g. ad libitum): NAFAG, Gossau SG pellets; ad libitum
- Water (e.g. ad libitum): ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 1°C
- Humidity 55 ± 5%
- Photoperiod (hrs dark / hrs light): 14 hours light / 10 hour dark

Route:

intradermal

Vehicle:

physiological saline

Concentration / amount:

0.1 mL (0.1 %)

Route:

intradermal

Vehicle:

physiological saline

Concentration / amount:

0.1 mL

No. of animals per dose:

20

Details on study design:

During the first week volumes of 0.1 mL of the test material (0.1%) in saline without adjuvant were injected intradermally on Monday at two sites (flank and back), and on Wednesday and Friday at each one site on the back. Twenty-one hours after administration, the animals were chemically depilated with Butoquick and three hours later the skin reaction was assessed under artificial lighting. The two largest diameters of the erythematous reaction in vertical alignment were measured (mm) and the skin-fold thickness was determined with a skin-fold gauge (mm). The individual "reaction volume" (µL) was calculated from these values for each reaction from each animal.

During the second and third week of induction the substance was mixed with adjuvant (Bacto Adjuvant, complete Freund's Adjuvant) in a 1:1 ratio. A total of 6 sensitising doses of 0.1 mL were injected intracutaneously into the skin of the neck on Monday, Wednesday and Friday. The reactions were not evaluated on these occasions. The test for skin sensitisation was performed two weeks after the last sensitising treatment with the adjuvant mixture. For the test 0.1 mL of the same substance formulation, as employed during the first testing week, was injected intradermally on the previously untreated flank. Twenty-four hours later the reaction site was evaluated in the same manner as during the first testing week.

A group of 20 guinea pigs treated in the same manner with the control vehicle alone served as negative and another group treated with dinitrochlorobenzene as positive control.

For each animal the mean value plus one standard deviation was calculated for the reaction volumes of the 4 intracutaneous injections from the first testing week. Ten days after the intracutaneous challenge injection sub irritant doses at the test compound were applied epicutaneously under occlusive dressing which were left in place for 24 hours.

Challenge controls:

Twenty guinea pigs were treated in the same way with the control vehicle alone served as the negative controls.

Positive control substance(s):

yes

Remarks:

dinitrochlorobenzene

Positive control results:

- Significant skin sensitisation
- Rate of positive reactors: 20/20 animals

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1%

No. with + reactions:

9

Total no. in group:

20

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.1%

No. with + reactions:

20

Total no. in group:

20

A positive reaction was observed.

Erythema scores (Draize scores), 24 hours after removal of dressing, by sex: Males: 4/10 had a score of 1 Females: 7/10 had a score of 1

Interpretation of results:

other: EU Category 1 (H317: May cause an allergic skin reaction).

Conclusions:

Significant differences between the test group and the vehicle-treated controls were found with the test material. The compound therefore has a skin sensitising (contact allergenic) potential in albino guinea pigs.

Executive summary:

The optimisation test was used, an intracutaneous sensitisation procedure, to determine the sensitisation potential of the test material. The test was performed on groups of 10 male and 10 female guinea pigs. Dinitrochlorobenazene was used as the positive control. Skin sensitisation was defined to occur for the challenge reaction whenever the reaction volume exceeded the mean value plus one SD of the 4 pre-sensitisation reponses.

Under the experimental conditions employed, significant differences between the test group and the vehicle treated controls were found with the test material. The compound therefore has a skin sensitising (contact allergenic) potential in albino guinea pigs.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Read-across to DMTC (Dimethyltin dichloride CAS No. 753 -73 -1) was not possible as no skin sensitisation study was performed on DMTC due to its corrosivity. In accordance with column 2 specific rules for adaptation from column 1) of Annex VIII of Regulation (EC) No. 1907/2006, the skin sensisation study required in section 8.3 can be omitted if the available data indicates that the substance should be classified for skin sensitisation or corrosivity. The available data on DMTC leads to its classification as corrosive. As a result read-across to DMTE (Dimethyltin bis (2-ethylhexyl thioglycolate) CAS No. 57583-35-4) was used for the registered substance.

Read-across to DMTE (Dimethyltin bis (2-ethylhexyl thioglycolate) CAS No. 57583-35-4)

In a Maurer Optimisation Test, the test material was weakly sensitising to the skin of male and female albino guinea pigs. At 24 hours after removal of the dressing, the Draize scores for 4/10 males and 7/10 females were 1. Based on the results of a Buehler Test, a blend of the test material in 50 % (w/v) acetone did not induce sensitisation in guinea pigs. The optimisation testing protocol provides a more-sensitive measure of sensitisation than the Buehler method.

Dermal sensitisation in guinea pigs from the key study: sensitiser

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No 1272/2008, the substance requires classification with respect to skin sensitisation Category 1 (H317: May cause an allergic skin reaction).