Lead Carbonate Intermediate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

August-December 2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Hypothesis for read-across: Lead (Pb) is the main component of the target substance, and considered the major driver for adverse effects based on its properties and relative quantity in the substance. For toxicity assessment the bioavailable part is relevant. From the target substance itself, Pb is poorly soluble. For read-across purpose, however, data from more soluble compounds was used. Therefore, it is considered that the used read-across data gives worst-case estimate on the adverse effects. Well-documented and corresponded to the requirements of the recommended Annex V Test Guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

There was one deviation from the study protocol which was concerned with the relative humidity section 6.2 Husbandry). On some days of the study the relative humidity was higher than 70%.

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An appropriate guinea pig maximization test is available, which would not justify conducting an additional LLNA due to animal welfare.

Test material

Test material information

Constituent 1

Reference substance name:

[phthalato(2-)]dioxotrilead

EC Number:

273-688-5

EC Name:

[phthalato(2-)]dioxotrilead

Cas Number:

69011-06-9

Molecular formula:

C8H4O6Pb3

IUPAC Name:

[phthalato(2-)]dioxotrilead lead(2+);oxygen(2-);phthalate

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): PEBETAL dibasic lead phthalate
- Physical state: fine, white powder
- Analytical purity: 74.15% Pb= 97.6% Pebetal
- Composition of test material, percentage of components: ash: 79.3%; water: 0.2%
- Lot/batch No.: D1/4296
- Expiration date of the lot/batch: July 31, 2004
- Storage condition of test material: At room temperature; Shelf life; at least one year after dispatch

In vivo test system

Test animals

Species:

guinea pig

Strain:

other: pirbright white

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles Rive Deutschland GmbH
- Age at study initiation:
- Weight at study initiation: males: 436-504 g; females: 395-481 g
- Housing: The guinea pigs were kept in collective housing up to a maximum of 5 animals per cage in a battery of cages, equipped with a paper disposal system.
- Diet (e.g. ad libitum): The animals received 2040 Teklad Global Guinea Pig Diet offered ad libitum.
- Water (e.g. ad libitum):Tap water as for human consumption was continuously available ad libitum via drinking nipples.
- Acclimation period: 19 days (range finding); 22 days ( main test)


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/-3 degrees centigrade
- Humidity (%): 37-76%
- Air changes (per hr): 16 times per hour and filtered adequately
- Photoperiod (hrs dark / hrs light): 12 hours dark/ 12 hours light with light on at 7:00 AM


IN-LIFE DATES: From: To:

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: Intradermal application: The solid test article was diluted with aqua ad iniectabilia and Freund's complete adjuvant to a final concentration of 5%. Dermal Application-the solid test article was used 50% in petrolatum

Concentration / amount:

For the intradermal injection, the test article was diluted with aqua ad iniectabilia and Freund's complete adjuvant to a final concentration of 5%. For the dermal application, the solid test article was used 50% in petrolatum.

Challenge

Route:

epicutaneous, occlusive

Vehicle:

other: Intradermal application: The solid test article was diluted with aqua ad iniectabilia and Freund's complete adjuvant to a final concentration of 5%. Dermal Application-the solid test article was used 50% in petrolatum

Concentration / amount:

For the intradermal injection, the test article was diluted with aqua ad iniectabilia and Freund's complete adjuvant to a final concentration of 5%. For the dermal application, the solid test article was used 50% in petrolatum.

No. of animals per dose:

10 test and 5 control animals

Details on study design:

RANGE FINDING TESTS: The range finding test was performed to determine the concentrations of the test article to be used in the main test. For the intradermal injection, the test article was diluted with aqua ad iniectabilia and Freund's complete adjuvant to a final concentration of 5%. Two animals were employed, skin reactions being recorded 48 and 72 hours after treatment. For the dermal application, the solid test article was used 50% in petrolatum. A closed patch exposure was effected by means of an occlusive bandage using swabs, Leukosilk, and non-irritating tape Elastoplast which enveloped the whole animal's trunk. Two animals were employed and skin reactions were recorded 48 and 72 hours post applicationem.


MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: Seven days after the injection, the injection sites were covered occlusively for 48 hours.
- Test groups: 10 guinea pigs
- Control group: 5 guinea pigs
- Site: Injections were made in the clipped intracapsular region on either side of the spine.
- Frequency of applications: Three pairs of intradermal injections (0.1 ml)
- Duration: Seven days after the injection, the injection sites were covered occlusively for 48 hours with a patch carrying the test article (50%) or, in control animals, the control article petrolatum.
- Concentrations: Test group: 1) FCA 50% (v/v) diluted in aqua ad iniectabilia, 2) test article 5% in peanut oil, 3) test article 5% in aqua iniectabilia/FCA. Control group: 1) FCA 50% (v/v) diluted in aqua ad iniectabilia, 2) peanut oil, 3) peanut oil 50% (v/v) diluted in FCA.




B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 14 days after the second stage of the induction
- Exposure period: 24 hours
- Test groups: 10 test animals
- Control group: 5 control animals
- Site: The challenge test was performed on a 5 x 5 cm clipped skin area on each flank.
- Concentrations: The test article was applied at the concentration of 50% to the left flank and the control article petrolatum to the right in a volume
of 0.5 g using the patch technique. In each case, the duration of exposure was 24 hours under an occlusive dressing.
- Evaluation (hr after challenge): 24 and 48 hours after patch removal the appearance of the challenge and re-challenge skin sites was observed and skin responses were gradfed on the basis of the classification system according DRAIZE. The animals werer weighed before treatment and at the end of the study. Al findings were recorded with respect to duration and severity on special report forms.




OTHER:

Challenge controls:

The control article petrolatum was applied to the left flank of the guinea pig in a volume of 0.5 g using the patch technique for 24 hours under an occlusive dressing.

Positive control substance(s):

yes

Remarks:

Assessed at least every 6 months by use of 25% and 50% "4-aminobenzoic acid ethyl ester (benzocaine)" (OECD406) in vaseline. The last test with acceptable levels of responses to this substance was performed from April 8 to 2 May 2003.

Results and discussion

Positive control results:

Sensitisation rate (50%) at 24 h: 70% Sensitisation rate (50%) at 48h: 70%
Sensitisation rate (25%) at 24 h: 30% Sensitisation rate (25%) at 24h: 30%

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No findings were observed in control animals.

Remarks on result:

no indication of skin sensitisation

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50% in petrolatum

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

None

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% in petrolatum. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: None.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

25% in vaseline

No. with + reactions:

3

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

25% in vaseline

No. with + reactions:

3

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 5

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

50% in vaseline

No. with + reactions:

7

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 6

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

50% in vaseline

No. with + reactions:

7

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Any other information on results incl. tables

There were no skin reactions after the dermal application in the induction phase. No allergic skin reactions were observed in the test animals after the challenge exposure 24 and 48 h after patch removal. No findings were observed in control animals. The sensitisation rate, i.e. the number of animals showing an allergic response expressed as a percentage of the total number of animals, was determined 24 and 48 h after patch removal and was 0% in test animals in each case. The corresponding reaction rate in control animals was 0%.

Justification for read-across: Lead (Pb) is the main component of the target substance, and considered the major driver for adverse effects based on its properties and relative quantity in the substance. For toxicity assessment the bioavailable part is relevant. From the target substance itself, Pb is poorly water soluble. For read-across purpose, however, data from more soluble compounds was used. Therefore, it is considered that the used read-across data gives worst-case estimate on the adverse effects.

See IUCLID Section 13 for Analogue approach report.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

According to the EEC Directive 2001/59/EEC, 6 August 2001 and the Gefahrstoffverordnung (GefStoffV) of 15 November 1999 (BGB1. I, p. 2233), thetest article PEBETAL dibasic lead phthalate can be classified as a "non-sensitiser" since no allergic responses were observed in test animals after the adjuvant test according to Magnusson & Kligman.

Executive summary:

The potential skin sensitising properties of the test article PEBETAL dibasic lead phthalate were assessed in the guinea pig maximisation test method, using 10 test and 5 control animals in the main test. Following the induction exposure to the test article (50% in petrolatum) or the vehicle petrolatum (control article), the animals of both groups were subjected two weeks later to a challenge with the test article (50% in petrolatum) as well as the control article. Responses to the challenge procedure were evaluated 24 and 48 h after the end of the exposure period.

Results: - No allergic skin reactions occurred in test animals 24 and 48 h after the end of the challenge procedure. The sensitisation was 0%.

-No findings were observed in control animals (reaction rate: 0%).

According to the EEC Directive 2001/59/EEC, 6 August 2001 and the Gefahrstoffverordnung (GefStoffV) of 15 November 1999 (BGB1 I. p. 2233), the test article PEBETAL dibasic lead phthalate can be classified as a "non-sensitiser" since no allergic responses were observed in test animals under the experimental conditions described.