Diammonium dihydrogenpyrophosphate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion, other

Remarks:

in vivo study performed in 1989. Considered to be reliable for use and comparable to current in vitro requirement.

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 26 June 1989 to 30 June 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In accordance with REACH Annex XI, Section 1.5, of Regulation (EC) No. 1907/2006 (REACH) the standard testing regime may be adapted in cases where a grouping or read-across approach has been applied.

The similarities may be based on:
(1) a common functional group
(2) the common precursors and/or the likelihood of common breakdown products via physical or biological processes, which result in structurally similar chemicals; or
(3) a constant pattern in the changing of the potency of the properties across the category

The proposed source chemical (is a mixture of ammonium orthophosphates and ammonium pyrophosphates and is highly soluble in water (> 10000 mg/L). In aqueous media soluble inorganic orthophosphates and pyrophosphates will dissociate to their ionic constituents; in this case ammonium and orthophosphate or pyrophosphate ions. Diammonium dihydrogenpyrophosphate will dissociate to ammonium cations and pyrophosphate anions. The pyrophosphate anions are unstable in aqueous solutions with the degree of instability varying according to pH. In distilled water they will hydrolyse slowly via abiotic mechanisms to orthophosphate. In natural waters a number of different processes can occur; abiotic hydrolysis, biotic degradation (as a result of the action of phosphatases which cleave pyrophosphates into orthophosphate subunits) and assimilation by organisms in the water. Thus, the target substance (diammonium dihydrogenpyrophosphate) and the source substance (mixture of ammonium orthophosphates and pyrophosphates) will be primarily absorbed as the same inorganic ions: ammonium and orthophosphate and are expected to behave in a similar manner under test conditions.
All (bio) transformation products of the source chemical are common to the target chemical and as such the data is considered to be adequate and reliable for use in the assessment of diammonium dihydrogenpyrophosphate for the toxicity hazard assessment.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See read-across justification report attached.

3. ANALOGUE APPROACH JUSTIFICATION
See read-across justification report attached.

4. DATA MATRIX
See read-across justification report attached.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

animals testing simultaneously, observation period not 14 days

Principles of method if other than guideline:

Three animals were tested simultaneously rather than sequentially.

Observation period was not stated to be 14 days, however no signs of erythema or oedema were noted so there was no reversibility of effects to monitor.

GLP compliance:

yes

Remarks:

Authentication declaring that the work was performed in accordance with GLP signed by study director 18 January 1990

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium polyphosphates impurities not otherwise specified

Molecular formula:

not applicable

IUPAC Name:

Ammonium polyphosphates impurities not otherwise specified

Test material form:

liquid

Details on test material:

The identity of the test material is not reported within the study report itself, however the data is referred to in the Toxicological Risks of Selected Flame Retardant Chemicals (2000), Subcommittee on Flame-Retardant Chemicals, Committee on Toxicology, Board on Environmental Studies and Toxicology, National Research Council. ISBN: 0-309-59232-1. The substance LR-2 is an ‘ammonium polyphosphate’ and the author provides the following additional information with regards to the chemical identity of LR2: ‘Based on information provided by the manufacturer (Stewart Miller, Albright and Wilson, pers. commun., Nov. 1, 1999), a typical species distribution of polyphosphates in LR2 is 20% orthophosphate, 40% pyrophosphate,

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Supplied by Cheshire Rabbit Farms limited , Duddon lodge, Tarporley. Cheshire
- Age at study initiation: no data
- Weight at study initiation: no data
- Fasting period before study: None
- Housing: Housed individually in aluminium cages with grid floors beneath which were peat moss filled trays
- Diet (e.g. ad libitum): Rabbit Diet, supplied by Special Diets Services, 1 Stepfield, Witham, Essex, CMS 3AD, provided ad libitum
- Water (e.g. ad libitum): Tap water provided ad libitum
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Mean maximum 19 °C, mean minimum 17 °C
- Humidity (%): 60%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

Test system

Type of coverage:

semiocclusive

Preparation of test site:

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): Test material used as supplied

Duration of treatment / exposure:

4 h

Observation period:

1, 24, 48 and 72 h

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: Test material was applied to intact skin on each rabbit under a 2.5 cm x 2.5 cm patch of gauze
- Type of wrap if used: The patch was covered with micropore tape and the trunk was loosely bound with Elastoplast Elastic Bandage which remained in position for 4h

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Skin wiped with water dampened tissues
- Time after start of exposure: 4 h

SCORING SYSTEM: Detailed in the Appendix

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 10 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 2

Irritation parameter:

erythema score

Basis:

animal: 11 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 3

Irritation parameter:

erythema score

Basis:

animal: 12 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 4

Irritation parameter:

edema score

Basis:

animal: 10 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 5

Irritation parameter:

edema score

Basis:

animal: 11 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Results 6

Irritation parameter:

edema score

Basis:

animal: 12 male

Time point:

other: Mean 24, 48 and 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritant / corrosive response data:

Details of individual reaction scores are given in the Table. No erythema or oedema were noted following a 4h semi-occlusive application of Amgard LR2 to rabbit skin.

Any other information on results incl. tables

Table

Animal/sex	Erythema				Oedema
	<1 h	24 h	48 h	72 h	<1 h	24 h	48 h	72 h
10 Male	0	0	0	0	0	0	0	0
11 Male	0	0	0	0	0	0	0	0
12 Male	0	0	0	0	0	0	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Amgard lR2 is non-irritant to rabbit skin.

Executive summary:

The acute dermal irritation potential of a test material, Amgard LR2, was investigated in New Zealand White rabbits. No erythema or oedema were noted following a 4 h semi-occlusive application of Amgard LR2 to rabbit skin. Amgard LR2 is non-irritant to rabbit skin.