Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 1984-05-15 to 1984-05-29
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Comparable guideline study with acceptable restrictions. Methodology used is similar to OECD guideline 402 and guideline OPPTS 870.1200 (limit test) with deviations (less than 5 animals tested). No details on experimental conditions. Only raw data reported.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
yes
Remarks:
less than 5 animals tested with intact skin
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Version / remarks:
Reliability scoring based on 1987 guideline for test n°402
Deviations:
yes
Remarks:
less than 5 animals tested with intact skin
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material: Sodium hypophosphite, sodium hypophosphite monohydrate
- Analytical purity: 86 % (expressed in anhydrous form)

- Impurities: Phosphorous acid Anh. (NaH2PO2) 0.44 %, iron (Fe) 2.3 ppm, Heavy metals (Pb) 2 ppm, Citric acid 0.22 %
- Purity test date: 1981-11-05
- Lot/batch No.: 106, 1981-10-29
- Other: pH= 4.7
No more data available

Test animals

Species:
rabbit
Strain:
not specified
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation:
Control rabbits mean weight: 2033 grams
Dosed rabbits mean weight: 1798 grams
For details: see table 2 in free text of results and discussions

IN-LIFE DATES: From: 1984-05-15 to 1984-05-29
No more data available

Administration / exposure

Type of coverage:
not specified
Vehicle:
not specified
Details on dermal exposure:
TEST MATERIAL
- Amount(s) applied: 2000 mg/kg body weight
No more data available
Duration of exposure:
24 hours
Doses:
One dose at 2000 mg/kg (limit dose)
No. of animals per sex per dose:
- Negative controls: 2 males and 2 females with for each sex 1 with abraded skin and 1 with intact skin
- 2000 mg/kg bw: 5 males (3 of which with abraded skin ) and 5 females (2 of which with abraded skin)
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 0, 7 and 14 days after exposure
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology and behaviour
Statistics:
No data

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD0
Effect level:
>= 2 000 mg/kg bw
Mortality:
No deaths were observed during the study.
cf table 1 in results and discussions free text
Clinical signs:

No systemic clinic signs were observed during the study at the dose-levels of 2000 mg/kg. Moderate erythema and mild to moderate oedema were observed on removal of the dressing. These local reactions cleared within 24 hours.
There were no effects in the control group.
Body weight:
cf table 2 in results and discussions free text
Gross pathology:
No abnormalities were observed at macroscopic examination.

Any other information on results incl. tables

Summarized results:

Table 1: Summarized results for combined sex of cumulative mortality

Acute dermal toxicity, 24h exposure, cumulative mortality
Day Dose (mg/ kg) Sex Dose (mg/ kg) Sex
0 M/F 2000 M/F
Cumulative mortality Cumulative mortality
0 0/4 0/10
1 0/4 0/10
2 0/4 0/10
3 0/4 0/10
4 0/4 0/10
5 0/4 0/10
6 0/4 0/10
7 0/4 0/10
8 0/4 0/10
9 0/4 0/10
10 0/4 0/10
11 0/4 0/10
12 0/4 0/10
13 0/4 0/10
14 0/4 0/10

Applicant's remark: 5 animals per sex have been tested. however some were tested on abraded skin. Therefore, the minimum number of tested animals is not achieved. The results show no mortality nor clinical signs whatever the sex and the abraded or intact skin. So, the deviation of the number of animals tested is considered as minor and the LD0 > 2000 mg/kg bw can be used for the classification

Table 2: Summarized results for body weight

Acute dermal toxicity, 24h exposure
Skin status Dose (mg/ kg) Sex Mean body weight in grams
Day 0 Day 7 Day 14
Intact  0 M 1794 2050 2259
Abraded 0 M 1714 2049 2338
Intact  0 F 2352 2528 2756
Abraded 0 F 2272 2456 2662
Intact  2000 M 1789 1909 2163
Abraded 2000 M 1846 2046 2275
Intact  2000 F 1750 1946 2151
Abraded 2000 F 1808 2033 2336

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: other: CLP (Reg. 1272/2008/EC)
Conclusions:
Sodium hypophosphite is not classified according to CLP (Reg. n° 1272/2008/EC).
Executive summary:

The objective of this study was to evaluate the toxicity of Sodium hypophosphite following a single dermal application to rabbits

according to methods similar to OPPTS 870.1200 and OECD 402 guidelines. There were no information in the report about GLP compliance.

The test item was applied to the skin of one group of five males (3 with abraded and 2 with intact skin) and five females (2 with abraded and 3 with intact skin) at the dose-level of 2000 mg/kg bw. One group of 2 males and 2 females acts as a control group (1 male and 1 female with abraded skin, 1 male and 1 female with intact skin).The test site was then covered by dressing for 24 hours. Clinical signs, mortality and body weight gain were checked for a period of 14 days following the single application of the test item. All animals were subjected to necropsy.

Neither mortality nor systemic clinical signs were observed during the study. A moderate erythema and a mild to moderate oedema were observed on removal of the dressing and cleared within 24 hours. The body weight gain of the animals was not affected by treatment compared to controls. No apparent abnormalities were observed at necropsy in any animal.

Under these experimental conditions, the dermal LD0of Sodium hypophosphite was equal or higher than 2000 mg/kg in rabbits

.