Phosphoric acid, 2-ethylhexyl ester, ammonium salt

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 December 2017 to 21 May 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study performed under GLP. All relevant validity criteria were met.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

09 October 2017

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium mono(2- ethylhexyl)phosphate

Molecular formula:

C8H22NO4P

IUPAC Name:

Ammonium mono(2- ethylhexyl)phosphate

Constituent 2

Reference substance name:

Ammonium bis(2-ethylhexyl) phosphate

EC Number:

225-615-3

EC Name:

Ammonium bis(2-ethylhexyl) phosphate

Cas Number:

4971-47-5

Molecular formula:

C16H38NO4P

IUPAC Name:

Ammonium bis(2- ethylhexyl)phosphate

Constituent 3

Reference substance name:

2-ethylhexyl diphosphate ammonium salts / esters of 2-ethylhexan-1-ol with diphosphoric acid and their corresponding ammonium salts

Molecular formula:

C8H23NO7P2

IUPAC Name:

2-ethylhexyl diphosphate ammonium salts / esters of 2-ethylhexan-1-ol with diphosphoric acid and their corresponding ammonium salts

Test material form:

liquid

Details on test material:

Storage Conditions: Room temperature.

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Han Wistar obtained from Charles River (UK) Ltd., Margate

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd., Margate
- Females (if applicable) nulliparous and non-pregnant: Yes
- Age at study initiation: 9 - 11 weeks
- Weight at study initiation: All within ±20 % of the mean value
- Fasting period before study: No
- Housing: The animals were housed in groups of up to five during the acclimatisation period in suspended, solid floor cages with wire lids. From the day prior to dosing (Day-1), the rats were housed in groups of three in similar cages. Bedding was provided on a weekly basis to each cage by use of clean European soft wood bedding (Datesand Ltd., Manchester, UK). Each batch of bedding was analysed for specific constituents and contaminants. No contaminants were present in bedding at levels which might have interfered with achieving the objective of the study. Results are retained on file at Covance.
- Diet (e.g. ad libitum): Throughout the study the animals had access to 5LF2 EU Rodent Diet 14%, which was freely available to the animals at all times. Each batch of diet had been analysed for specific constituents and contaminants by the manufacturer.
- Water (e.g. ad libitum): Mains water was provided ad libitum via cage mounted water bottles. The water was periodically analysed for specific contaminants.
- Acclimation period: The condition of the animals was assessed daily throughout the acclimatisation period of 7 to 10 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24 ºC
- Humidity (%): 45-65 %
- Air changes (per hr): 15-20
- Photoperiod (hrs dark / hrs light): 12:12

IN-LIFE DATES: not stated

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: the day before treatment Electric clippers were used to remove all hair from the dorsum .
- % coverage: Approximately 10% of total body surface
- Type of wrap if used: A dense gauze patch was placed over the treated skin and retained in place by an elasticated, open-weave, adhesive compression bandage

REMOVAL OF TEST SUBSTANCE
- The dermal test site of each rat was lightly brushed clean of any solid residues and swabbed with water-moistened cotton wool before the animal was returned to the holding cage.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount applied: 2000 mg/kg bw
- Constant volume or concentration used: 1.049 g/mL

Duration of exposure:

24h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations and mortality checks were conducted at approximately 0.15, 0.5, 1, 2, 3, 4 hours and subsequently twice daily on Days 2, 3 and 4 and once daily from the fifth to last day of the observation period. Local effects were examined once daily for 14 days after the completion of the 24-hour exposure period. Full details on the scoring and criteria (consistent with Draize) are given in the full study report. Individual bodyweight were recorded prior to application of the test item on Day -1 (before dosing) and on Days 1, 4, 8 and 15.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

There were no deaths

Clinical signs:

other: There were no clinical signs of reaction to treatment

Gross pathology:

No macroscopic changes were noted at necropsy.

Any other information on results incl. tables

Table  1. Dermal Reactions at Dose level 2000 mg/kg

Day	Dermal Reaction	Animal Number
		2	3	4
2	Erythema Oedema Other	2 0 -	2 0 -	2 0 -
3	Erythema Oedema Other	3 0 SC	2 0 SC	2 0 SC
4	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
5	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
6	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
7	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
8	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
9	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
10	Erythema Oedema Other	1 0 SC	2 0 SC	2 0 SC
11	Erythema Oedema Other	0 0 SC, FU	2 0 SC	2 0 SC
12	Erythema Oedema Other	0 0 SC, FU	2 0 SC	2 0 SC
13	Erythema Oedema Other	0 0 SC, FU	1 0 SC	1 0 SC
14	Erythema Oedema Other	0 0 SC, FU	1 0 SC	1 0 SC
15	Erythema Oedema Other	0 0 SC, FU	0 0 SC	0 0 SC

Key:

-       No other dermal changes apparent

SC       Scabbing

FU       Patchy hair growth

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study the dermal LD50 was established to exceed 2000 mg/kg bw in female Han Wistar (Crl:WI(Han)) strain rat. Applicant assessment indicates, under the conditions of this study, and according to the GHS criteria, the LD50 cut-off value was considered to be greater than 5000 mg/kg body weight.

Executive summary:

A study was performed according to OECD TG 402; Acute Toxicity (Dermal) and in accordance with GLP to assess the acute dermal toxicity of the test substance in the Han Wistar (Crl:WI(Han)) strain rat. Three animals were given a single dose of the test item, 24 hour under occluded dermal application of the undiluted test item to intact skin at a dose level of 2000 mg/kg body weight followed by 14 days observation.

There was no mortality during the study. There were no signs of system toxicity or abnormalities on necropsy. All animals showed expected gains in body weight during the study. There was well defined to moderate erythema was noted at the application sites of all treated animals on Days 2 and 3, with very slight to well-defined erythema persisting up to Day 14. Other adverse dermal reactions noted were scabbing and patchy hair growth which developed from Day 3 and persisted to the end of the observation period.

Under the conditions of this study, the dermal LD50 was established to exceed 2000 mg/kg bw in female Han Wistar (Crl:WI(Han)) strain rat. Applicant assessment indicates, under the conditions of this study, and according to the GHS criteria, the LD50 cut-off value was considered to be greater than 5000 mg/kg body weight.