Diphenyl[4-(phenylsulfanyl)phenyl] sulfonium hexafluoroantimonate(1-)

Endpoint summary

Description of key information

Skin Sensitisation: Category 1A for skin sensitisation; OECD 406- GPMT. P.A.M. Daamen. 1988

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

Study period:

13 September 1988 - 14 October 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted to international guideline although the test item purity was not disclosed.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1981

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

1984

Deviations:

not specified

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

In accordance with REACH Regulation (EC) 1907/2006: Annex VII: column 2 as amended by Commission Regulation (EU) 2017/706, a well documented study report conducted before 10 May 2017, following a method equivalent or similar to guideline with acceptable deviations is available. This is sufficient to fulfil the standard information requirement in accordance with REACH Regulation (EC) 1907/2006: Annex XI: section 1.1.2 since adequate and reliable (with restrictions) study information has been provided suitable for classification and labelling and/or risk assessment.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga, Sulzfeld, FRG.
- Females (if applicable) nulliparous and non-pregnant: Yes
- Microbiological status of animals, when known: Not reported
- Age at study initiation: approximately 8 weeks at study initiation
- Weight at study initiation: 335 - 476 g.
- Housing: 2 animals per cage metal cages with wire-mesh floor
- Diet (e.g. ad libitum): standard diet including ascorbic acid (1600 mg/kg) in addition hay was provided once a week.
- Water (e.g. ad libitum): Free access to mains tap water
- Acclimation period: At least 7 days
- Indication of any skin lesions: No

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 21ºC
- Humidity (%): 45- 75 %
- Air changes (per hr): Not indicated
- Photoperiod (hrs dark / hrs light): 12 h: 12 h (light: dark)
- IN-LIFE DATES: Not reported

Route:

intradermal and epicutaneous

Vehicle:

propylene glycol

Concentration / amount:

Induction phase
The animals received intradermal injection of 0.1 ml of test item (5% and 10 % w/w in propylene glycol).
Followed topical exposure to 0.5 ml of 50% (w/w in propylene glycol

Route:

epicutaneous, occlusive

Vehicle:

propylene glycol

Concentration / amount:

0.05 ml of the test item at concentration on 50%, 25%, 10% & 0% (w/w) held in place for 24hours

No. of animals per dose:

20 Treated animals
10 control animals

Details on study design:

Test methods:
The animals were allocated to two groups; one experimental group go 20 animals and one group of 10 animals representing the control groups.
The remaining animals were used for primary irritation experiments. the main study comprised two phases: induction and challenge.

Primary irritation experiments:
Primary irritation experiment included intracutaneous injections and epicutaneous application of several concentrations of the test substance diluted in propylene glycol (OPG, Utrecht, the Netherlands). For animals received epicutaneous applications of the test substance at 50%, 25%, 10% and 5 % (w/w) in amount of 0.05 ml using square chamber (v.d. Bend, Brielle, The Netherlands). The skin reactions of these four animals are summarised. One animal received 4 x 0.1 ml intracutaneous injections of 5% (w/w) and 0.5 ml 50% (w/w) test substance epicutaneously applied.

Induction Phase:

Day 0, Control Group.

the fur from an approximately 4 cm x 6 cm between the shoulders was removed by clipping. Three pairs of intradermal injections were made in such a way that the three injections formed a row on each sides of the midline. The six injections were made within the boundaries of 2 cm x 4 cm area, over which a patch was applied one week later, the injections consisted of:
A. 0.1 ml vehicle alone: propylene glycol (OPG, Utrecht, the Netherlands).
B. 0.1 ml Freunds Complete Adjuvant (FCA, DIFCO, Detroit, USA) emulsified with an equal volume of distilled water (Pyrogen free, Ferensius AG, Bad Homburg, FRG).
C. 0.1 ml FCA, emulsified with equal volume of propylene glycol.
The injections A & B are made close to each other and most cranial, the injection C were made caudal to Injections A & B.

Day 0, Experimental group.
These animals received the same treatment as the control; groups., but the injections consisted of:
A. 0.1 ml of the test substance (5% w/w in propylene glycol).
B. 0.1 ml of FCA emulsified with an equal volume of distilled water
C. 0.1 ml of the test substance (10% w/w in propylene glycol) emulsified with equal volume of FCA.

Day 6, Control group and Experimental group.

the skin of the shoulder area was treated with sodium dodecyl sulfate (Merck, Darmstadt, FRG), 10% in petrolatum (Ph. Ned, Brocacef, Maarssen, The Netherlands).

Day 7, Control Group. The same area in the shoulder region was clipped. A patch of Metalline (Lohamann, Neuwid FRG) (2 cm x 4 cm), moistened with 0.5 ml propylene glycol, was fixed onto a strip of micropore-tape (3M co., St. Paul, USA) which was applied to the shoulder skin over the injection sites and secured by an elastic bandage (Caban, 3M Co., St. Paul, USA). After 48 hours, the dressings were removed and the treated skin scored according to the scoring system used in the primary irritation experiment.

Day 7, Experimental group.
These animals were exposed and score in a similar manner to the controls, to approximately 0.5 ml of the 50% (w/w, in propylene glycol) test substance concentration.

Challenge Phase.

The challenge
phase was carried out on day 21. In both groups the left flank was shaved. The test substance, diluted in propylene glycol, was applied in an amount of 0.05 ml on square chamber (v.d. Bend, Brielle, The Netherlands), mounted on micropore -tape. Each animal received 4 different concentration go the test substance; all animals were treated similarly. The concentration tested were; 50%, 25%, 10%, and 5% (w/w). The elastic bandage (Coban) was kept in the place for 24 hours. Twenty-four and forty-eight hours after removal of the dressing the reading were made. For proper evaluation of the skin reactions, the treated side was closely shaved on day 23 after the first reading.

Observation:
The challenge application sites of both test and control animals were assessed for skin reactions, which were recorded according to the following

No skin reaction ………………………………….0
Red spots (Scattered reactions) …………….1
Moderated but confluent reactions……..2
Redness and swelling ………………………….3
Intense reddening and swelling ……………4
Any observed signs of general toxicity and local effects other than those indicated above were recorded. Moderate but confluent redness (grad 2) was considered a positive response to the challenge, provided that such a reaction was not observed in the control group.

Interpretation of results:

The readings after application of the challenge dose on day 21 were compared to assess the sensitisation rate i.e. the number of sensitised animals in proportion of the total number of animals in the experimental groups. The sensitisation rate was compared with the Classification of Kligman

Challenge controls:

10 animals treated with sodium dodecyl sulfate 10% in petrolatum

Positive control substance(s):

no

Positive control results:

A previous positive control experiment was conducted in Sep 1987 (NOTOX 0000/809) in order to validate the animals and test procedure.
Test substance: Formaldehyde solution 37% (p.a. art. 4003, Merck, Darmtadt, FRG)
Induction phase: 5% (v/v) in milli-ro water
Challenge phase: 5 %, 3% & 0.5% (v/v) in milli-ro water
A sensitisation rate of 100% was obtained to the 5%, 3% & 0.5% concentrations.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

13

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

13

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

10

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50%

No. with + reactions:

19

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

18

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

15

Total no. in group:

20

Clinical observations:

No signs of systemic toxicity

Remarks on result:

positive indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

25%

No. with + reactions:

3

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

10%

No. with + reactions:

1

Total no. in group:

10

Clinical observations:

No signs of systemic toxicity

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

other: not reported

Group:

positive control

Dose level:

5%, 3% and 0.5%

Remarks on result:

other: It is reported that a sensitisation rate of 100% was obtained for the 5%, 3% and 0.5% concentrations

Table 2. Individual Bodyweights and Challenge Skin Readings

Animal No.	Day -1	Induction Day 9 Reading	Day 23 Readings				Day 24 Readings				Day 24	Comments
	BW^a(gram)	50^a	50^b	25	10	0	50^b	25	10	0	(BW)^a(gram)
Exper.
106	384	0	2	2	2	0	2^s	3^s	3^s	0	598	Sensitised
107	432	0	3	2	2	0	4^cs	3^s	3^s	0	516	Sensitised
108	402	0	1	1	1	0	3^s	3^s	3^s	0	544	Sensitised
109	386	0	0	0	0	0	1	1	1	0	521	Not sensitised
110	340	0	0	0	0	0	1	1	0	0	456	Not sensitised
111	386	0	2	1	1	0	2^s	2^s	1^s	0	524	Sensitised
112	418	0	2	2	1	0	2	2	2	0	544	Sensitised
113	387	0	2	2	1	0	2^s	2	2	0	534	Sensitised
114	375	0	0	0	0	0	1^s	1^s	1^s	0	508	Not sensitised
115	419	0	1	1	0	0	1	1	0	0	543	Not sensitised
116	412	0	3	2	2	0	3^s	3^s	3^s	0	556	Sensitised
117	389	0	1	1	1	0	1	1	1	0	510	Not sensitised
118	412	0	1	1	1	0	2^s	2^s	2^s	0	548	Sensitised
119	395	0	0	0	0	0	1^s	1	1	0	489	Not sensitised
120	373	0	2	1	0	0	2^s	2^s	2^s	0	487	Sensitised
121	382	0	0	0	0	0	1	0	0	0	484	Not sensitised
122	390	0	2	0	0	0	1^s	1^s	0	0	452	Sensitised
123	341	0	0	0	0	0	0	0	0	0	503	Not sensitised
124	373	0	0	1	0	0	2^s	2^s	2^s	0	469	Sensitised
125	354	0	3	3	3	0	3^s	3^s	3^s	0	456	Sensitised
Contr.
126	463	0	0	0	0	0	0	0	0	0	625
127	405	0	0	0	0	0	0	0	0	0	506
128	412	0	0	0	0	0	0	0	0	0	606
129	438	0	0	0	0	0	1	1	0	0	525
130	469	0	0	0	0	0	0	0	0	0	628
131	476	0	0	0	0	0	0	0	0	0	623
132	391	0	0	0	0	0	0	0	0	0	515
133	381	0	0	0	0	0	0	0	0	0	518
134	406	0	0	0	0	0	0	1	0	0	556
135	402	0	0	0	0	0	0	1	0	0	545

a) Bodyweight

b) Concentrations in propylene glycol (% w/w)

c) This site showed brownish discolouration; a sign of necrosis

s) This site showed scaliness

Table 3. Erythema from Exposure of the guinea pig skin from irritation test

Animal no.	Day -7 BW^a (g)	24 Hour Readings^b				48 Hour Readings^b				Day -1 BW^a(g)
		50^c	25	10	5	50^c	25	10	5
136	371	0	0	0	0	0	0	0	0	414
137	336	0	0	0	0	0	0	0	0	343
138	368	0	0	0	0	0	0	0	0	379
139	335	0	0	0	0	0	0	0	0	366

a = body weight

b = time after removal of dressing

c = concentrations in propylene glycol (%, v/v)

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

Under the study conditions, the test substance was considered to be a moderate sensitiser Category 1A.

Executive summary:

A study in compliance with OECD 406 (1988) was conducted to assess the sensitising potential of the test substance in female guinea pigs of the Dunkin-Hartley strains. One experimental group of 20 animals and one control group of 10 animals were used. The remaining animals were used in the primarily irritation experiments where four animals received an epicutaneous application of the test item in propylene glycol at 50, 25, 10 & 5 % (w/w) in an amount of 0.05ml and one animal received 4 x 0.1 ml intracutaneous injections of 5% (w/w) test item and 0.5 ml 50% (w/w) test item epicutaneously applied. No signs of skin irritation or systemic toxicity was observed in all four animals.

Induction phase: fur from appropriately 4 cm * 6 cm between the shoulders were removed by clipping. Six injections were made over a 2 cm * 4 cm area, for control groups, 0.1 ml of vehicle alone, 0.1 ml Freunds complete Adjuvant (FCA) emulsified with an equal volume of distilled water and 0.1 ml FCA emulsified with an equal volume of propylene glycol.  Experimental groups received 0.1 ml test item (5% w/w in propylene glycol), 0.1 ml of Freunds complete Adjuvant (FCA) emulsified with an equal volume of distilled water and 0.1 test item in (10% w/w in propylene glycol) emulsified with equal volume of FCA.  The injection sites were covered with patch a week later.

On day 7:  Control groups received 0.5 ml of vehicle over the injected sites under occlusive condition for 48 hours. While the experimental group received 0.5 ml of the 50% (w/w in propylene glycol) under occlusive conditions for 48 hours.

Challenge Phase: on day 21, 0.05 ml of the test item at concentrations of 50, 25, 10, 0% (w/w) diluted in propylene glycol were applied under occlusive condition for 24 hours. Reading was conducted after 24 and 48 hours after removal of occlusive patches.

Results: Following induction up to 50% concentration of the test item in propylene glycol was no skin reaction was observed during this phase.  

Challenge phase produced positive skin reactions (grad 2 or more) in twelve animals at 50%, eleven at 25% and nine at 10% concentrations. These reactions were characterised with moderate, confluent redness and in some animals, oedema, scaliness and necrosis was observed.  Three control animals showed red spots in reaction to one or two of the tested concentrations. No consistent signs of systemic toxicity were observed in an animal during the study.

Under the condition of the study, it was concluded that the test item, is a sensitiser at a rate of 60%, an indication of moderate sensitivity (Kligman 1966). Applying the general classification and labelling requirements for Directive 67/548/EEC (amended by Directive 83/467/EEC), the test item should be labelled a skin sensitiser.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

A study in compliance with OECD 406 (1988) was conducted to assess the sensitising potential of the test substance in female guinea pigs of the Dunkin-Hartley strains. One experimental group of 20 animals and one control group of 10 animals were used. The remaining animals were used in the primarily irritation experiments where four animals received an epicutaneous application of the test item in propylene glycol at 50, 25, 10 & 5 % (w/w) in an amount of 0.05ml and one animal received 4 x 0.1 ml intracutaneous injections of 5% (w/w) test item and 0.5 ml 50% (w/w) test item epicutaneously applied. No signs of skin irritation or systemic toxicity was observed in all four animals.

Induction phase: fur from appropriately 4 cm * 6 cm between the shoulders were removed by clipping. Six injections were made over a 2 cm * 4 cm area, for control groups, 0.1 ml of vehicle alone, 0.1 ml Freunds complete Adjuvant (FCA) emulsified with an equal volume of distilled water  and 0.1 ml FCA emulsified with an equal volume of propylene glycol.  Experimental groups received 0.1 ml test item  (5% w/w in propylene glycol), 0.1 ml of Freunds complete Adjuvant (FCA) emulsified with an equal volume of distilled water and 0.1 test item in (10% w/w in propylene glycol) emulsified with equal volume of FCA.  The injection site were covered with patch a week later.

On day 7:  Control groups received 0.5 ml of vehicle over the injected sites under occlusive condition for 48  hours. While the experimental group received 0.5 ml of the 50% (w/w in propylene

glycol) under occlusive conditions for 48 hours.

Challenge Phase: on day 21, 0.05 ml of the test item at concentrations of 50, 25, 10, 0% (w/w) diluted in propylene glycol were applied under occlusive condition for 24 hours. Reading was conducted after 24 and 48 hours after removal of occlusive patches.

Results: No skin reaction was observed during the induction phase.  Challenge phase produced positive skin reactions (grad 2 or more) in twelve animals at 50%, eleven at 25% and nine at 10% concentrations. The reactions were characterised with moderate, confluent redness and in some animals, oedema, scaliness and necrosis was observed.  Three control animals showed red spots in reaction to one or two of the tested concentrations. No consistent signs of systemic toxicity were observed in an animal during the study.

Under the condition of the study, it was concluded that the test item, is a sensitiser at a rate of 60%, an indication of moderate sensitivity (Kligman 1966). The test item meets the classification for Cat 1B for skin sensitisation according to GHS and CLP  (EC 1272/2008) regulations.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The test item, is a sensitiser at a rate of 60%, an indication of moderate sensitivity (Kligman 1966). The test item meets the classification for Category 1A for skin sensitisation according to GHS and CLP  (EC 1272/2008) regulations.