Registration Dossier

Administrative data

Description of key information

- Skin sensitisation: not a skin sensitiser (OECD 406 / GPMT, GLP, K, rel. 1)

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:
From 1994-01-12 to 1994-02-19
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Study performed according to OECD test guideline No. 406 and in compliance with GLP.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Version / remarks:
1992
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes (incl. certificate)
Remarks:
UK GLP compliance programme (inspection date: 1992-10-27)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
At the time of study performance, the LLNA method was not adopted.
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: D. Hall, Darley Oaks, Burton-on-Trent, Staffordshire, England.
- Age at study initiation: young
- Weight at study initiation: 250-300 g
- Housing: in groups of 5 in stainless steel cages.
- Diet (e.g. ad libitum): antibiotic free diet ad libitum (SQC, FD1 guinea pig diet with added vitamin C produced by Special Diets Services, Witham, Essex).
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days for the animals used for the preliminary study and 19 days for those selected for the main tests.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-24 °C. On 2 occasions the recorded temperature fell by 1 °C below the protocol specified range. These deviations are considered not to have affected the outcome of the study.
- Humidity (%): 28-66 %. On one occasion the relative humidity was recorded to be less than the minimum specified in the protocol. This deviation is considered not to have affected the outcome of the study.
- Air changes (per hr): no data
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: no data
Route:
intradermal
Vehicle:
other: light liquid paraffin
Concentration / amount:
25 % / 3 x 0.1 mL
Day(s)/duration:
Day 1
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, occlusive
Vehicle:
other: ethanol
Concentration / amount:
100 %
Day(s)/duration:
Day 8 / 48 hours
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: ethanol
Concentration / amount:
100 % and 50% / 24 hours
Day(s)/duration:
Day 22
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
5 preliminary test animals, 20 test animals, 10 control animals
Details on study design:
RANGE FINDING TESTS:
- Intradermal injections: 100%, 50%, 25%, 10%, 5%, and 1% v/v in light liquid paraffin. 1 guinea-pig pre-treated 7 d before with 4 intradermal injections of 1:1 FCA/water. The highest concentration which produced an acceptable localised response at each injection site was 25%.
- Topical induction and challenge: 100%, 50%, 25% and 12.5% v/v in ethanol. 4 guinea-pigs pre-treated with FCA/water as described above. Undiluted test article was found to be non-irritant when applied topically and was therefore selected for the topical induction phase of the main study. Undiluted test article and a 50% v/v concentration of the test article in ethanol were selected for the challenge concentrations.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2, intradermal injections and topical application
- Exposure period: 48h for topical application
- Test groups:
INTRADERMAL: 3 pairs of intradermal injection (0.1 mL) on Day 0 as follows:
- 1/ 50% v/v FCA/distilled water
- 2/ test substance 25% in light liquid paraffin
- 3/ test substance 25% in 50:50 distilled water/FCA
Six days after the intradermal induction, as the undiluted test material was non-irritant, the test area of all test and control animal was treated topically with 0.5 mL of 10 % sodium lauryl sulphate in light liquid paraffin in order to produce irritation.
TOPICAL: 7 days after intradermal injections, the test substance (100%) was applied (patches of Whatman No. 3 filter paper, 4cm x 2cm) and covered with a strip of "Blenderm" surgical tape secured in place and wrapped with "Elastoplast" elastic adhesive bandage (occlusive tape).
- Control group: similarly treated with the exception that the ethanol was topically applied instead of the test substance
- Site: shaved dorsal area between the shoulders

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 14 d after the topical induction application, i.e. 21 d after study initiation
- Exposure period: 24 hours
- Test groups: 100% on the anterior aspect of the left flank, 50% v/v in ethanol on the posterior aspect of the left flank. Similarly treated than topical induction (patches 2cm x 2 cm)
- Control group: similarly treated with the exception that the test substance was omitted
- Site: left flanks
- Concentrations: 100% and 50% v/v in ethanol
- Evaluation (hr after challenge): approximately 24 and 48 hours after patch removal.
Challenge controls:
None
Positive control substance(s):
yes
Remarks:
Benzocaine
Positive control results:
Ethyl p amino benzoate (Benzocaine) was used as a positive control as this is known to be a mild to moderate sensitiser. The material was administered as a 1 % concentration in propylene glycol for the intradermal injections and a 4 % concentration in acetone for the topical induction. Challenge was conducted at concentrations of 4 % and 3 % in acetone. This positive control study took place during the period from 1993-07-07 to 1993-07-31.
Three animals in the test group gave positive response to 4 % benzocaine resulting in a response incidence of 30 %. Neither challenge concentration elicited a response in any control animal at any of the observation times during the study. These results confirm that benzocaine is a mild to moderate sensitizer under the conditions of this study and the test system is therefore considered to be validated.
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
1
Total no. in group:
20
Clinical observations:
grade 1 (discrete or patchy erythema)
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
4 %
No. with + reactions:
3
Total no. in group:
10
Remarks on result:
positive indication of skin sensitisation

none

Interpretation of results:
GHS criteria not met
Conclusions:
Under the test conditions, ST 06 C 93 is not classified as a skin sensitiser.
Executive summary:

In a dermal sensitisation study performed according to the EU test method B.6 and in compliance with GLP, ST 06 C 93 was tested in female Hartley guinea-pigs using the Guinea-Pig Maximisation Test method (20 treated animals + 10 controls).

The preliminary study determined the concentration to be used for the induction and challenge phases of the main study.

 

ST 06 C 93 diluted in light liquid paraffin at 25% (v/v) was administered by injection for intradermal induction. As the substance was not a skin irritant, 24 hours prior to the topical application, the site was pre-treated with 0.5 mL 10% w/w sodium lauryl sulphate in light liquid paraffin. Topical induction was performed with the test material as supplied, 7 days after intradermal injections. For the challenge, 21 days after study initiation, it was tested at 100% and 50 % v/v in ethanol.

 

ST 06 C 93 produces evidence of skin sensitisation in one animal at 100 %, resulting in a response incidence of 5 %.

 

No response was exhibited by any animal of the control group.

 

The historical positive control, benzocaine, produces evidence of skin sensitisation in three of ten animal at 100 %, resulting in a response incidence of 30 %.These results confirmed that benzocaine is a mild to moderate sensitiser under the conditions of this study and the test system was therefore considered to be validated.

 

Under the test conditions, ST 06 C 93 is not classified according to the Regulation EC No. 1272/2008 (CLP) and to the GHS.

This study is considered as acceptable and satisfies the requirement for sensitisation endpoint.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

A key study was identified (Toxicol 1994, rel. 1). This dermal sensitisation study was performed according to the EU test method B.6 and in compliance with GLP. ST 06 C 93 diluted in light liquid paraffin at 25% (v/v) was administered by injection for intradermal induction. As the substance was not a skin irritant, 24 hours prior to the topical application, the site was pre-treated with 0.5 mL 10% w/w sodium lauryl sulphate in light liquid paraffin. Topical induction was performed with the test material as supplied, 7 days after intradermal injections. For the challenge, 21 days after study initiation, it was tested at 100% and 50 % v/v in ethanol. ST 06 C 93 produces evidence of skin sensitisation in one animal at 100 %, resulting in a response incidence of 5 %. No response was exhibited by any animal of the control group. The historical positive control, benzocaine, produces evidence of skin sensitisation in 30 % of the animals. These results confirmed that benzocaine is a mild to moderate sensitiser under the conditions of this study and the test system was therefore considered to be validated.

Moreover, in an occlusive repeated insult patch tests conducted in 108 volunteer subjects, the substance does not show evidence of sensitisation when tested at 20% in diethyl phthalate (TKL, 2001).

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

no data

Justification for classification or non-classification

Harmonised classification:

The substance has no harmonized classification according to the Regulation (EC) No. 1272/2008 (CLP).

Self-classification:

Based on the available data no self-classification is proposed according to the CLP and to the GHS.

No data was available for respiratory sensitisation. However, this substance is not a skin sensitizer, therefore according to Figure R.7.3 -2 of the Chapter R.7 (V 4.1 - October 2015) the chemical is not considered as a respiratory sensitizer.