Phosphoric acid, butyl ester, sodium salt

Endpoint summary

Description of key information

Based on the fïndings in the adjuvant sensitization test in guinea pigs the test substance does not have a skin sensitising potential.

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:

2008-06-25 to 2008-08-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1993

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The study was conducted before the LLNA was established as standard in vivo method.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 5-6 weeks at beginning of acclimatisation
- Weight at study initiation: 332 g-362 g
- Housing: Individually in Makrolontype-4 cages with standard softwood bedding ("Lignocel", Schill AG, 4132 Muttenz / Switzerland)
- Diet: Pelleted standard Provimi Kliba 3418 guinea pig breeding / maintenance diet batch no. 27108, containing Vitamin C (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland), ad libitum
- Water: tap water ad libitum
- Acclimation period: Under laboratory conditions after health examination. No acclimatization for the animals of the pretest.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/- 3
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

50 % and 100 % test item were selected for the intradermal induction and the epidermal induction, respectively.

Day(s)/duration:

intradermal injection on day 1, epidermal injection on day 8

Adequacy of induction:

other: The concentration of test item used for each induction exposure was well-tolerated systemically and was the highest to cause mild to moderate skin initation.

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

15 %

Day(s)/duration:

test day 22

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

5 animals in control group
10 animals on test group

Details on study design:

RANGE FINDING TESTS:
The concentrations of the test item required for the induction and challenge were selected based on the results of a preliminary study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (one intradermal and one epidermal)
- Exposure period: epidermal exposure for 48 hours (occlusive dressing)
- Test groups: one test group
- Control group: control group treated with water (vehicle)
- Site: intradermal injection: An area of dorsal skin from the scapular region (approximately 6 x 8 cm), 3 pairs of injuections,
epidermal exposure: scapular area (approximately 6 x 8 cm)
- Concentrations: intradermal induction of sensitization in the test group was performed with a 50 % dilution of the test item in purified water and in an emulsion of Freund's Complete Adjuvant (FcA)/physiological saline.
epidermal induction: 100 %

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: day 22 of the experiment
- Exposure period: dressings were left in place for 24 hours
- Test groups: The test and control guinea pigs were treated in the same way.
- Site: 5 x 5 cm area on the left and right flank
- Concentrations: 15 % ( left flank), water only (right flank)
- Evaluation (hr after challenge): 21 h after reomval of the dressing, 48 h and 72 h after start of challenge exposure

Challenge controls:

none

Positive control substance(s):

yes

Remarks:

ALPHA-HEXYLCINNAMALDEHYDE

Positive control results:

Discrete/patchy to moderate/confluent erythema with or without scaling was observed in nine out of ten test animals at the 24- and 48-hour reading after the challenge treatment with ALPHA-HEXYLCINNAMALDEHYDE at 1 % in PEG 300 (left shoulder). Five test animals showed discreteþatchy erythema at the 24-hour reading after treatment with ALPHAHEXYLCINNAMALDEHYDE at 0.1% in PEG 300 (left flank).

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0 (right flank)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no abnormalities

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0 (right flank)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no abnormalities

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

15 % test item (left flank)

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

no abnormalities

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

15 % test item (left flank)

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no abnormalities

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0 (rigth flank)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormalities

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

0 (right flank)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormalities

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

15 % test item (left flank)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormalities

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

15 % test item (left flank)

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no abnormalities

Remarks on result:

no indication of skin sensitisation

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

1 %

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

no abnormalities

Remarks on result:

positive indication of skin sensitisation

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

1 %

No. with + reactions:

9

Total no. in group:

10

Clinical observations:

no abnormalities

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the fïndings in the adjuvant sensitization test in guinea pigs the test substance does not have a skin sensitising potential.

Executive summary:

In order to assess the cutaneous allergenic potential of the test substance, a Maximization-Test was performed in 15 (10 test and 5 control) female albino Dunkin Hartley guinea pigs, in accordance with OECD Guideline No. 406 and the Council Regulation (EC) No 44012008,8.6. The intradermal induction of sensitization in the test group was performed in the nuchal region with a 50 % dilution of the test item in purified water and in an emulsion of Freund's Complete Adjuvant (FcA)/physiological saline. The epidermal induction of sensitization was conducted for 48 hours under occlusion with the test item at 100 % one week after the intradermal induction. The animals of the control group were intradermally induced with purifred water and FCA/physiological saline and epidermally induced with purified water under occlusion. Two weeks after epidermal induction the control and test animals were challenged by epidermal application of the test item at 15 % in purified water and purified water alone under occlusive dressing. Cutaneous reactions were evaluated at 24 and 48 hours after removal of the dressing. No toxic signs were evident in the guinea pigs of the control or test group. No deaths occurred. No positive/skin reactions were observed in the control and test animals when treated with either purified water only or when treated with the test item at 15 % in purified water.

Based on the above mentioned fïndings the substance does not have to be classified and labelled as a skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Maximisation test

Assay 1 (supporting study):

In order to assess the cutaneous allergenic potential of the test item, a Maximization-Test was performed in 20 (10 test and 10 control) female albino Dunkin Hartley guinea pigs, in accordance with OECD Guideline No. 406 and the Council Regulation (EC) No 440/2008, 8.6. The intradermal induction of sensitization in the test group was performed in the nuchal region with a 50 % dilution of the test item in purified water and in an emulsion of Freund's Complete Adjuvant (FCA)/physiological saline. The epidermal induction of sensitization was conducted four hours under occlusion with the test item at 100 % one week after the intradermal induction, the animals of the control group were intradermally induced with purified water and FCA/physiological saline and epidermally induced with purified water under occlusion. Two weeks after epidermal induction the control and test animals were challenged by epidermal application of the test item at 75 % in water and water alone under occlusive dressing. Two weeks thereafter a scond challenge was conducted in the same way. A naive control group (control group 2) was included. Test item concentrations used were 50 and 25 %. Cutaneous reactions were evaluated at 24 and 48 hours after removal of the dressing. No toxic signs were evident in the guinea pigs of the control or test group. No deaths occurred. For validation of sensitivity of the Maximization-Test of B. Magnusson and A.M Kligman(1969) as well as the sensitivity of the test system used, a known sensitizer ALPHA-HEXYLCINNAMALDEHYDE was selected as a positive control. The positive control substance produced skin reactions proving the skin sensitizing property. In the test group (treated with the test item), all animals showed skin reactions after the 24 h reading and 5 animals after the 48 h reading after the first challenge (75 % test item). Two out of 5 animals of the control group 1 showed skin reactions at the 24 h and one animal at the 48 h reading after being treated with the test item at 75 %. To distinguish between sensitizing and false positive results (due to irritation) obtained from the first challenge, a second challenge was conducted. After the second challenge (59 % test item) all animals of the control group 1 showed skin reactions at the 24-and 48 h readings. The scores of the local signs were slightly more severe when compared to the first challenge. Skin reactions were also found in two out of five control group 2 animals. No effects were seen in the three groups after treatment with water only. The fact that all control 1 animals already sensitized in the first challenge showed a booster effect in incidence in the second challenge with the test item at a lower concentration and the fact that a slight booster effect in severity was observed in the test animals could imply that the reactions are more likely to be skin sensitization rather than irritation. However, the reactions observed in the naive control 2 group do not support this assumption and lead to the conclusion that the test item at 50 % is irritant. As a conclusion, the results were equivocal and further test results are necessary for evaluation of the skin sensitising property.

Assay 2 (key study):

In order to assess the cutaneous allergenic potential of the test substance, a further Maximization-Test was performed in 15 (10 test and 5 control) female albino Dunkin Hartley guinea pigs, in accordance with OECD Guideline No. 406 and the Council Regulation (EC) No 44012008,8.6. The intradermal induction of sensitization in the test group was performed in the nuchal region with a 50 % dilution of the test item in purified water and in an emulsion of Freund's Complete Adjuvant (FcA)/physiological saline. The epidermal induction of sensitization was conducted for 48 hours under occlusion with the test item at 100 % one week after the intradermal induction. The animals of the control group were intradermally induced with purifred water and FCA/physiological saline and epidermally induced with purified water under occlusion. Two weeks after epidermal induction the control and test animals were challenged by epidermal application of the test item at 15 % in purified water and purified water alone under occlusive dressing. Cutaneous reactions were evaluated at 24 and 48 hours after removal of the dressing. No toxic signs were evident in the guinea pigs of the control or test group. No deaths occurred. No positive/skin reactions were observed in the control and test animals when treated with either purified water only or when treated with the test item at 15 % in purified water.

Based on the above mentioned fïndings the substance does not have to be classified and labelled as a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the substance is not considered to be classified for skin sensitisation under Regulation (EC) No 1272/2008, as amended for the twelth time in Regulation (EU) No 2019/521.