Disodium hydrogenorthophosphate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion, other

Remarks:

Study was performed prior to the update of the REACH Regulation and prior to the validation of in vitro test methods.

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1971

Report date:

1971

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

Animals were examined at 24 and 72 hours only. No data reported on reversibility of effects. Study uses intact and abraded skin. No controls were included in the study.

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

Animals were examined at 24 and 72 hours only. No data reported on reversibility of effects. Study uses intact and abraded skin. No controls were included in the study.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Disodium hydrogenorthophosphate

EC Number:

231-448-7

EC Name:

Disodium hydrogenorthophosphate

Cas Number:

7558-79-4

Molecular formula:

H3O4P.2Na

IUPAC Name:

disodium hydrogen phosphate

Details on test material:

- Name of test material : Disodium phosphate
- Analytical purity: No data

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

No data

Test system

Type of coverage:

not specified

Preparation of test site:

other: Shaved, abraded and intact

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied : 0.5 g


VEHICLE
Used as received.

Duration of treatment / exposure:

24 hours

Observation period:

Up to 72 hours

Number of animals:

6, 3 males and 3 females.

Details on study design:

TEST SITE
- Type of wrap if used: Rubber (occlusive)


REMOVAL OF TEST SUBSTANCE
No data


SCORING SYSTEM:
The Draize dermal method of testing primary irritant substance as described in the Code of Federal Refulations under the Federal Hazardous Substances Labelling Act, Part 191.11, Chapter 1, Title 21.

Compounds producing combined averages (primary irritation indexes) of 2 or less are only mildly irritating; indexes from 2 to 5 are moderate irritants and those with scores above 5 are considered severe or primary irritants.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 hours

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 hrs

Score:

0

Max. score:

4

Reversibility:

fully reversible

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 hrs

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 4

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 hrs

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritant / corrosive response data:

The primary dermal irritation index is calculated by the following:

Total ÷ 4 = Primary dermal irritation index

Other effects:

No data

Any other information on results incl. tables

Table 1: Results for Disodium phosphate

Exposure time Hours	Rabbit No.							Mean
		8M	15M	16M	32F	33F	34F
		Score	Score	Score	Score	Score	Score
Erythema
24	Intact	1	1	0	0	0	0	0.33
72	Intact	0	0	0	0	0	0	0.00
24	Abraded	3	4	3	3	3	4	3.33
72	Abraded	3	3	3	3	3	2	2.83
Subtotal								6.49
Oedema
24	Intact	0	0	0	0	0	0	0.00
72	Intact	0	0	0	0	0	0	0.00
24	Abraded	1	2	1	1	1	1	1.17
72	Abraded	2	1	2	1	1	1	1.33
Subtotal								2.50
Total score								8.99
(Total/4) Primary Irritation Index								2.25
Result							Moderate Irritant

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

This study has been selected as the key study because the results are sufficient in order to derive a reliable conclusion on classification and labelling when viewed in conjunction with the supporting data.
Disodium hydrogenorthophosphate is not considered to be classified according to Regulation (EC) No. 1272/2008 (EU CLP).