Phosphorus

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Scientific sound non GLP study similar to Bühler Method with restricted reporting. Sufficient detail available to be able to judge the study as reliable for this end point.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

yes

Remarks:

10 animals in the treatment group, positive control group only, 10 topical applications

GLP compliance:

no

Remarks:

performed before GLP guideline

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

Phosphorus

EC Number:

231-768-7

EC Name:

Phosphorus

Cas Number:

7723-14-0

IUPAC Name:

phosphine

Constituent 2

Reference substance name:

phosphorus

EC Number:

918-594-3

Cas Number:

7723-14-0

Molecular formula:

(P)n (Phosphorus red modification)

IUPAC Name:

phosphorus

Details on test material:

- Name of test material (as cited in study report): oiled red phosphorus Albright and Wilson, LDT. Lot LT 22 RED PHOSPHORUS)
- Substance type: element
- Physical state: solid / powder
- Analytical purity: > 94,6 % +- 1,20 %
- Impurities (identity and concentrations): < 0,0055 % +- 0,0020 % yellow phosphorus
- Composition of test material, percentage of components:approx. 94,6 % total phosphorus, 0,08 % +- 0,010 % mineral oil

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

Details on test animals and environmental conditions:
TEST ANIMALS
- Source: charles River Breeding Laboratories, Inc., MA, USA
- Age at study initiation: females: 7weeks males: 9 weeks
- Housing: wired bottom cages
- Diet (e.g. ad libitum): Purina Rat Chow
- Water (e.g. ad libitum): Acified water (pH 2.5)
- Acclimation period: 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72° to 76°F
- Humidity (%): 39 to 54 percent relative humidity
- Photoperiod (hrs dark / hrs light): 12h dark / 12h with artificial illumination.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

physiological saline

Induction 2

Concentration / amount:

Study I: intradermal injection 0.1 mL of a 0.1% (w/v) suspension
Study II: concentrations for the patch test range-finding studies were 1.0, 2.0 and 5.0%; 10% in the main study

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

physiological saline

Challenge 2

Concentration / amount:

Study I: intradermal injection 0.1 mL of a 0.1% (w/v) suspension
Study II: concentrations for the patch test range-finding studies were 1.0, 2.0 and 5.0%; 10% in the main study

No. of animals per dose:

10

Details on study design:

The potential of Red Phosphorus to produce skin sensitization was evaluated by two methods
- Study I: Intradermal injections (females)
- Study II: externally applied patches containing the test material (males)

- Study I:
Red Phosphorus was suspended in sterile isotonic saline. 0.1 mL of a 0.1% (w/v) suspension was used for intradermal injection.

- Study II:
The suspensions' concentrations for the Patch test range-finding study were 1, 2 and 5%. In the main study 10% (w/v) suspension was used. All animals used in the patch tests received 0.5 mL of the test material. The positive control was 2,4-Dinitro-1-chlorobenzene, 0.1 mL applied as 0.05% (w/v) solution.
The method included application of the test material or positive control substance to a shaved area of the flank or back 3 times per week for 10 applications. A challenge application was made to a site other than the sensitization site 15 days after the last application. Immediately before each sensitizing application, the reaction from the previous application was evaluated according to the numerical scoring system for skin irritation responses (Draize scoring system). The site of challenge application was evaluated 24 and 48 hours after the challenge. Reaction to the test material at the application site was determined by measurement of the diameter with calipers and estimation of the height and color. The guinea pigs were observed daily for toxic signs.
Topical application for the patch test was accomplished with a dosing band. The band consisted of two 3-inch long strips of 1-inch wide cloth adhesive tape overlapped 0.25 inch. The adhesive side was lined with gauze. A window 2x2 cm square was cut in the band and it was attached to the shaved back of the guinea pig with adhesive tape. The test material was applied to the back of the animal through the dosing window and the window was covered with filter paper. The test substance remained in contact with the skin for 6 hours and was then removed by wiping the area first with cotton soaked in glycerin and then with a gauze pad. In the range-finding study, 2 males per group were treated with 1, 2 or 5% (w/v) suspensions of Red phosphorus once daily for 5 days. Three groups of 10 guinea pigs each were used in the main study. Group 1 received 0.1 mL of a 0.05% (w/v) solution of 2,4-dinitro-1-chlorobenzene in acetone. Group 2 was treated with 10 applications of 0.5 mL 10% (w/v) suspension of Red Phosphorus in sterile saline. Group 3 received 0.5 mL of a 20% Red phosphorus suspension at the challenge application only.

Challenge controls:

No data

Positive control substance(s):

yes

Remarks:

2,4-dinitro-1-chlorobenzene

Results and discussion

Positive control results:

Study I:
The positive control guinea pigs' reactions during sensitization were encrustment after 4 to 5 doses. Within 24 hours after challenge doses, the injection sites were hard, red and crusty.
StudyII:
All control animals showed a clear skin reaction after challenge application.

In vivo (non-LLNA)

Results

Results 1

Reading:

other: after challenge on study day 35 (study I)

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1 %

No. with + reactions:

3

Total no. in group:

8

Clinical observations:

slight hair loss

Remarks on result:

other: Reading: other: after challenge on study day 35 (study I). . Hours after challenge: 24.0. Group: test group. Dose level: 0.1 %. No with. + reactions: 3.0. Total no. in groups: 8.0. Clinical observations: slight hair loss.

Results 2

Reading:

other: 1 st reading (study II)

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no data

Remarks on result:

other: Reading: other: 1 st reading (study II). . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no data.

Results 3

Reading:

other: 2 nd reading (study II)

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no data

Remarks on result:

other: Reading: other: 2 nd reading (study II). . Hours after challenge: 48.0. Group: test group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no data.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Red Phosphorus showed no sensitizing properties in this study

Executive summary:

Similar to Buehler Test Red Phosphorus was applied topically 10 times to the skin of guinea pigs at a concentration of 10% (w/w). 15 days after the last application the challenge was conducted and the skin scored according to the Draize scale:

The skin and surrounding hair were stained the same red shade as Red Phosphorus which was not the same color as erythema.There was no response to the challenge dose of Red Phosporus.