Phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16th December 2009 and 15th January 2010.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of GLP inspection: 15/09/09 Date of Signature on GLP certificate: 26/11/09

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of bis[2,4-bis(2-methylbutan-2-yl)phenyl] 4-(2-methylbutan-2-yl)phenyl phosphite and 2,4-bis(2-methylbutan-2-yl)phenyl bis[4-(2-methylbutan-2-yl)phenyl] phosphite and tris[4-(2-methylbutan-2-yl)phenyl] phosphite.

EC Number:

700-485-5

Cas Number:

939402-02-5

Molecular formula:

Mixture of 4 components, the molecular formulae of which are: C33 H45 O3 P, C38 H55 O3 P, C43 H65 O3 P and C48 H75 O3 P

IUPAC Name:

Reaction mass of bis[2,4-bis(2-methylbutan-2-yl)phenyl] 4-(2-methylbutan-2-yl)phenyl phosphite and 2,4-bis(2-methylbutan-2-yl)phenyl bis[4-(2-methylbutan-2-yl)phenyl] phosphite and tris[4-(2-methylbutan-2-yl)phenyl] phosphite.

Test material form:

liquid: viscous

Details on test material:

Description: clear colourless viscous liquid
Date received: 05 November 2009
Expiry date: 15 June 2010
Storage conditions: Approximately 4°C in the dark under nitrogen

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd, Hillcrest, Belton, Loughborough, UK.
- Age at study initiation: Twelve to twenty weeks old.
- Weight at study initiation: 2.18 to 2.63 kg.
- Housing: The animals were individually housed in suspended cages.
- Diet: Certified Rabbit Diet. ad libitum.
- Water: mains drinking water ad libitum
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23°C
- Humidity (%): 30 to 70%
- Air changes (per hr): at least fifteen changes per hour.
- Photoperiod (hrs dark / hrs light): The lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

N-LIFE DATES: From: Day 0 To: 72 hours

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): not applicable

VEHICLE
- Amount(s) applied (volume or weight with unit): not applicable
- Concentration (if solution): not applicable
- Lot/batch no. (if required): not applicable
- Purity: not applicable

Duration of treatment / exposure:

One patch was removed after 3 minutes, the second patch was removed after 1 hour and the final patch was removed after 4 hours.

Observation period:

72 hours

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure:three areas each of 2.5 cm x 2.5 cm.
- % coverage: 100% under patch
- Type of wrap if used: cotton gauze patch secured in position with a strip of surgical adhesive tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Distilled water
- Time after start of exposure: One patch was removed at each of three time points: 3 minutes, 1 hour and 4 hours after application. Any residual test material was removed by gentle swabbing with cotton wool soaked in distilled water.

SCORING SYSTEM: Draize J H (1959) "Dermal Toxicity" In: Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. Association of Food and Drug Officials of the United States, Austin, Texas, p.46 59

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 68790 Male

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: mean

Results 2

Irritation parameter:

erythema score

Basis:

animal: 68796 Male

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 24 hours

Remarks on result:

other: mean

Results 3

Irritation parameter:

erythema score

Basis:

animal: 68797 Male

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 24 hours

Remarks on result:

other: mean

Results 4

Irritation parameter:

edema score

Basis:

animal: 68790 Male

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: mean

Results 5

Irritation parameter:

edema score

Basis:

animal: 68796 Male

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: no effects observed

Remarks on result:

other: mean

Results 6

Irritation parameter:

edema score

Basis:

animal: 68797 Male

Time point:

other: Mean of 24, 48 and 72 hrs

Score:

0

Max. score:

4

Reversibility:

other: No effects observed

Results 7

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Score:

0.8

Irritant / corrosive response data:

3 minute exposure period: Well-defined erythema and very slight oedema were noted at the treated skin site 1 hour after patch removal and at the 24 hour observation with very slight erythema noted at the 48 hour observation.

1 hour exposure period: Very slight erythema was noted at the treated skin site 1 hour after patch removal and at the 48 hour observation with well-defined erythema and very slight oedema noted at the 24 hour observation.

4 hour exposure period: Well-defined erythema and very slight oedema was noted at one treated skin site immediately after patch removal and at the 1 and 24 hour observations with very slight erythema noted at the two remaining treated skin sites at the 24 hour observation. Very slight erythema was noted at one treated skin site at the 48 hour observation. Two treated skin sites appeared normal at the 48 hour observation and the remaining treated skin site appeared normal at the 72 hour observation.

Other effects:

All animals showed expected gain in bodyweight during the study.

Any other information on results incl. tables

Result of TER. Determination of the electrical resistance was not possible due to the presence of adhered residual test material, despite repeated attempts to remove it. Visual inspection of the skin discs showed no obvious evidence of damage or discolouration.

Conclusion. Following assessment of the data the test material was considered unlikely to have the potential to cause corrosion in vivo.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The test material produced a primary irritation index of 0.8 and was classified as a mild irritant to rabbit skin according to the Draize classification scheme. No corrosive effects were noted. The test material did not meet the criteria for classification as irritant or corrosive according to EU or GHS labelling regulations. No symbol or risk phrase are required.

Executive summary:

Introduction. The study was performed to assess the irritancy potential of the test material to the skin of the New Zealand White rabbit. The method was designed to meet the requirements of the following:

-  OECD Guidelines for the Testing of Chemicals No. 404 “Acute Dermal Irritation/Corrosion” (adopted)

-   Method B4 Acute Toxicity (Skin Irritation) of Commission Regulation (EC) No. 440/2008

Initial considerations. In the absence of data suggesting that the test material was unlikely to produce severe irritation/corrosion, an ex vivo pre‑screen test, the Transcutaneous Electrical Resistance (TER) Assay, was performed. The results of the pre-screen test indicated that the test material was considered not to be corrosive to the skin and the in vivo study was performed.

Results. 3-minute and 1 hour semi-occluded applications of the test material to the intact skin of one rabbit produced no corrosive effects. A single 4 hour, semi-occluded application of the test material to the intact skin of three rabbits produced very slight to well-defined erythema and very slight oedema. No corrosive effects were noted.

Conclusion. The test material did not meet the criteria for classification as irritant or corrosive.