Sodium 2-biphenylate

Endpoint summary

Description of key information

Skin sensitisation (OECD 406): not sensitising

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:

02 - 31 Mar 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 81-6 (Skin Sensitisation)

Version / remarks:

1984

Deviations:

not specified

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

A non-LLNA test is available that was performed prior to the current data requirements, stipulated in Regulation (EC) No 1907/2006. In accordance with the same Regulation, the data was included to avoid unnecessary testing.

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., USA
- Age at study initiation: Approximately 9 weeks
- Weight at study initiation: 365 - 446 g
- Housing: 5 animals were housed per cage.
- Diet: Purina Certified Guinea Pig Chow #5026, ad libitum
- Water: Tap water, ad libitum
- Acclimation period: At least 1 week
- Indication of any skin lesions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 40 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

- IN-LIFE DATES: From: 02 Mar 1994 To: 31 Mar 1994

Route:

epicutaneous, occlusive

Vehicle:

other: distilled water

Concentration / amount:

0.5%

Day(s)/duration:

3 single treatments (6 h exposure) every 7 days within 21 days

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: distilled water

Concentration / amount:

0.1%

Day(s)/duration:

single treatment (6 h exposure)

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: A preliminary skin irritation study was conducted in order to determine a slightly irritating dose level as well as to establish the highest non-irritating concentration of the test substance. Guinea pigs were clipped free of hair on the left and right side the day prior to dosing. Single application of a 0.4 mL aliquot of a 0.1, 0.5, 1, 5 or 10% solution of the test substance in distilled water was topically applied to the skin for 6 h, in up to 3 application sites per animal. 2 guinea pigs were used per dose level. Based on the results of this preliminary skin irritation study, the dose levels 1, 5 and 10% solutions of the test substance in distilled water produced moderate to marked erythemas after 24 and 48 h, respectively. The treatment group exposed to the dose level of 0.5% showed slight erythema in 1/2 guinea pigs at the 48-h reading time point. No erythema were observed in both animals at the 0.1% dose level. Edema were not determined in all treatment groups at the 24- and 48-h reading time points, respectively. Thus, based on the results of this study, a dose level of 0.1% was considered to be the highest non-irritant concentration and 0.5% the highest concentration causing mild-to-moderate skin irritation.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 h
- Test groups: test substance in distilled water
- Control group: positive control
- Site: left flank
- Frequency of applications: every 7 days
- Duration: 0 - 21 Days
- Concentration: 0.5%

B. CHALLENGE EXPOSURE
- No. of exposures: 1 (challenge)
- Day(s) of challenge: 35 (challenge)
- Exposure period: 6 h
- Test groups: test substance in distilled water
- Control group: positive control
- Site: right flank
- Concentration: 0.1%
- Evaluation (hr after challenge): 24 and 48 h after patch removal

Challenge controls:

10 naïve male guinea pigs, 5 received a 0.1% solution of the test substance in distilled water and 5 received the positive control.

Positive control substance(s):

yes

Remarks:

(10% solution of [trade name] (CAS 1675-54-3) epoxy resin in dipropylene glycol monomethyl ether)

Positive control results:

Challenge application with the positive control caused slight to moderate erythema, considered to reflect a hypersensitivity response, at the test site on nine of ten animals, with no effect noted in the corresponding naïve control animals.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Induction: 0.5%; Challenge: 0.1%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Neither erythema nor edema were observed.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: 0.5%; Challenge: 0.1%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Neither erythema nor edema were observed.

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

Induction: 10%; Challenge: 10%

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

Very slight, slight or moderate erythema (scores of 0.5 - 2) were observed.

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

Induction: 10%; Challenge: 10%

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

Slight or moderate erythema (scores of 1 - 2) were observed.

Group:

negative control

Remarks on result:

not measured/tested

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No. 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A Guinea pig maximisation test was performed with the test substance according to OECD guideline 406 and under GLP conditions (The Toxicological Research Laboratory, 1994). A range-finding study was performed to establish suitable dose levels for the induction and challenge treatments. In the main study, 10 male Hartley guinea pigs received three dermal applications each of a 0.5% suspension of the test substance in distilled water for 6 hours under occlusive conditions during the three-week induction period. Two weeks thereafter, the challenge treatment was performed by topical application of the test substance as a 0.1% suspension in distilled water for 6 hours under occlusive conditions. Observations were made 24 and 48 hours after challenge treatment. Ten naïve male guinea pigs served as control, 5 from those received a 0.1% solution of the test substance in distilled water and 5 received the positive control. Challenge application with the positive control caused slight to moderate erythema, considered to reflect a hypersensitivity response, at the test site on nine of ten animals, with no effect noted in the corresponding naïve control animals. Examination of the application sites at challenge reading time points 24 and 48 h revealed no skin reaction in any of the 10 animals tested; thus, the test substance was not a skin sensitizer under the test conditions used.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on skin sensitisation with the test substance sodium 2-biphenylate (CAS 132-27-4) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008, and are therefore conclusive but not sufficient for classification.