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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no precise data, 72 hours minimum
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study with acceptable restrictions performed using a method equivalent to the OECD guideline 404. No data on the purity of the tested substance, no observation period for the reversibility and no scoring at 60 minutes after patch removal.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1977
Report Date:
1977

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
other: DOT, Hazardous Materials Regulations, 49 CFR Part 173.240
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
. Reliability scoring based on 1981 OECD guideline for test n° 404.
Deviations:
yes
Remarks:
: no observation period for reversibility, no scoring at 60 minutes after patch removal.
GLP compliance:
no
Remarks:
study predates GLP requirements.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material: Sodium hypophosphite, Filter Press Cake
- Batch number: T-6103

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: 2530 - 3167 grams

No more data available

Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
other: each animal served as its own control
Amount / concentration applied:
TEST MATERIAL
- Amount applied: 500 milligrams by rabbit on shaved backs (intact or abraded sites)
Duration of treatment / exposure:
4 hours
Observation period:
72 hours
Number of animals:
3 males and 3 females
Details on study design:
TEST SITE
- Type of wrap if used: occlusive
- Testing area: intact (shaved) and abraded skins

REMOVAL OF TEST SUBSTANCE
- Washing: tepid tap water
- Time after start of exposure: 4 hours

SCORING SYSTEM: according to OECD guideline 404

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
overall irritation score
Basis:
mean
Time point:
other: 24, 72 hours
Score:
<= 0.6
Irritation parameter:
erythema score
Remarks:
Test item applied onto intact skin
Basis:
animal #1
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
0.66
Max. score:
4
Reversibility:
no data
Irritation parameter:
erythema score
Remarks:
Test item apllied onto the intact skin
Basis:
animal #2
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
0.66
Max. score:
4
Reversibility:
no data
Irritation parameter:
erythema score
Remarks:
Test item applied onto the intact skin
Basis:
animal #3
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
1
Max. score:
4
Reversibility:
no data
Irritation parameter:
edema score
Remarks:
Test item applied onto the intact skin
Basis:
animal #1
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
0
Max. score:
4
Irritation parameter:
edema score
Remarks:
test item applied onto the intact skin
Basis:
animal #2
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
0
Max. score:
4
Irritation parameter:
edema score
Remarks:
Test item applied onto the intact skin
Basis:
animal #3
Time point:
other: mean of the 24, 48 and 72-hour readings
Score:
0.33
Max. score:
4
Reversibility:
no data
Irritant / corrosive response data:
For raw data see tables in the "remarks on results" freetext.

Any other information on results incl. tables

Raw data for irritant/corrosive response:

Each animal was evaluated according to the grading scale of theOECD 404 guideline.

Table 1: Primary skin irritation scoring values

   

          Intact skin

          Abraded skin

   

          Hours

          Hours

 Observations  Grade  4 24  48  72   4 24  48  72 

Erythema,

Eschar formation             

 0

     

 2/3

 2/3

   

 1/3

 1

 3/3  3/3  3/3  1/3

 1/3

 3/3  3/3  2/3

 2

               

 3

               

 4

               

Edema

Formation             

 0

 3/3 3/3 3/3  2/3   3/3 3/3  3/3  3/3 

 1

     

 1/3

       

 2

               

 3

               

 4

               

Table 2: Corrosion results

            Intact skin    Abraded skin
 

          Hours

          Hours

 Observations  4 24  48  72 

 4

24 

48 

72 

 Necrosis

(corrosion)

 0/3 0/3  0/3  0/3  0/3  0/3  0/3  0/3 

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: other: CLP (Reg. 1272/2008/EC)
Conclusions:
Under the experimental conditions of this study and according to the criterai laid down in CLP (Reg 1272/2008/EC), the test item Sodium hypophosphite is considered as non-irritant to the skin.
Executive summary:

The potential of sodium hypophosphite to induce skin irritation or corrosion was assessed in adult New Zealand white rabbits (3 males and 3 females) using the 49 CFR Part 173.240 method from the US Hazardous Materials Regulations. This method was comparable to the OECD 404 guideline issued in 1981. The study predates GLP requirements.

The rabbits were dermally exposed to 500 mg of sodium hypophosphite for 4 hours on prepared shaved backs. 3 animals received the test item onto an intact skin while the remaining received the test item onto an abraded area.The test substance was held in contact with the skin by means of an occlusive dressing. Cutaneous reactions were observed 24, 48 and 72 hours after removal of the dressing.

A slight erythema (scoring value 1) was observed in all animals at the 24 -hour reading and was still persistent in 1out 3 animals treated onto an intact skin and 2 out 3 animals treated on an abraded area at the 72 -hour reading. Only one animal with intact skin showed a slight oedema (soring value 1) at the 72 -hour reading.

According to the criteria laid down in EC regulation 1272/2008/EC, Sodium hypophosphite is considered as non-irritant to the skin and is not classified.