Phosphorus

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

11 June 2010 - 18 June 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to official EC and OECD test guidelines, and in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

triiron phosphide

IUPAC Name:

triiron phosphide

Constituent 2

Reference substance name:

Triiron phosphide

EC Number:

234-682-8

EC Name:

Triiron phosphide

IUPAC Name:

234-682-8

Constituent 3

Reference substance name:

12023-53-9

Cas Number:

12023-53-9

IUPAC Name:

12023-53-9

Details on test material:

- Name of test material (as cited in study report): Ferrophosphorus (Fe3P)
- Substance type: inorganic
- Physical state: black powder (solid)
- Analytical purity: Fe: 82.7%, P: 15.7%
- Lot/batch No.: 1068487
- Expiration date of the lot/batch: 15 February 2011
- Storage condition of test material: room temperature

Test animals

Species:

other: EpiDerm™ threedimensional human skin model.

Details on test animals or test system and environmental conditions:

The test material was applied for three minutes and one hour to the EpiDerm™ threedimensional human skin model. The model consisted of normal, human-derived epidermal keratinocytes, which had been cultured on 0.6 cm2 inserts to form a multilayered, highly differentiated model of the human epidermis with a functional multilayered stratum corneum.

Test system

Controls:

other: refer to above entry

Amount / concentration applied:

Nominal weights of 25 mg of the test material was dispensed over each tissue. The test material was then wetted with 25 μl purified water.
The positive and negative controls were in liquid form and were applied by dispensing a volume of 50 μl over each tissue using a pipette.

Duration of treatment / exposure:

three minutes and one hour

Number of animals:

Triplicate tissues each for test substance, negative control ( purified water) and positive control (8.0 N potassium hydroxide)

Details on study design:

When all tissues from one batch had been transferred to a holding plate, the inserts were transferred to the MTT assay plate which was then incubated for three hours at 37±1°C in a humidified atmosphere of 5% CO2 in air. After three hours, the tissues were rinsed with DPBS and transferred to 1 ml per well extraction solution (isopropanol) in 24-well plates. A further 1 ml was then added to each insert. The tissues were extracted overnight at room temperature, without shaking.

Results and discussion

In vivo

Results

Irritation parameter:

other:

Remarks on result:

other: The test material, Ferrophosphorus (Fe3P), elicited a mean tissue viability of 109.1% for three minute contact and 97.5% for one hour contact and was non-corrosive in the Epiderm™ Skin Corrosivity test.

Any other information on results incl. tables

Assessment of viability

The mean optical density (OD) reading from the triplicate measurements was calculated for each tissue. The mean OD reading was expressed as a percentage of the mean negative control value.

Assay acceptance criteria

Negative control - The mean OD from the negative control tissue in the MTT assay is an indicator of tissue viability after the shipping and storage procedure and under the specific conditions of the assay. The mean OD of each duplicate negative control value should be

≥0.8.

Positive control - The mean relative tissue viability of the positive control, 8.0 N potassium hydroxide, for the one hour application should be less than 15%.

Inter-tissue viability difference - In the range of 20 – 100% viability the coefficient of variation (CV) should not exceed 0.3.

Results

Reduction of MTT by test material

After the one hour incubation, the colour of the test material, Ferrophophorus (Fe3P) / MTT mixture (orange with black powder) and MTT solution control (orange) remained unchanged, from the start of incubation. Therefore, the test material had not reduced the MTT.

Assay validity

Negative control: The mean optical density of each duplicate negative control value for the three minute and one hour contact were 1.707 and 1.805, respectively. Both values were above the minimum assay acceptance value of 0.8.

Positive control: The mean relative tissue viability of the positive control, 8.0 N potassium hydroxide, for the one hour application was 7.0%. This value was below the maximum acceptable value of 15%.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Study results do not indicate a requirement for classification as corrosive to skin. Criteria used for interpretation of results: EU

Conclusions:

The test material, Fe3P, elicited a mean tissue viability of 109.1% for three minute contact and 97.5% for one hour contact and was non-corrosive in the Epiderm™ Skin Corrosivity test.