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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
The study was performed between 16 May 2012 and 30 May 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.1200 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
other: Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF), Testing Guidelines for Toxicology Studies, 12 NohSan No. 8147, amended 26 June 2001
Deviations:
no
Qualifier:
according to
Guideline:
other: Japanese Ministry of Health and Welfare, 1992
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
semi-solid (amorphous): gel
Remarks:
migrated information: paste
Details on test material:
Sponsor's identification: [[(2-hydroxyethyl)imino]bis(methylene)]-bisphosphonic acid, equilibrium mixture with 4-(Phosphonomethyl)-2-hydroxy-2-oxo-1,4,2-oxazaphosphorinane, sodium salt
CAS number : 22036-78-8
Identifiers : TIS O3270
Description : white paste
Batch number : LE12579A
Date received : 03 April 2012
Expiry date : 01 August 2013
Storage conditions: room temperature in the dark
Test item contained 10.95% water

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
Five male and five female Wistar (RccHan:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non pregnant. After an acclimatisation period of at least five days the animals were selected at random and given a number unique within the study by indelible ink-marking on the tail and a number written on a cage card. At the start of the study the animals weighed at least 200 g, and were eight to twelve weeks of age. The weight variation did not exceed ±20% of the mean weight for each sex.

The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 Hour exposure period and in groups of five, by sex, for the remainder of the study. Free access to mains drinking water and food (2014C Teklad Global Rodent diet) was allowed throughout the study. The diet, drinking water and bedding were routinely analysed and were considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
unchanged (no vehicle)
Details on dermal exposure:
PREPARATION OF TEST ITEM:
The test item contains 10.95% water. For the purposes of the study the test item concentration was corrected for this. The test item was weighed out according to each animal's individual bodyweight and moistened with distilled water prior to application.
The absorption of the test item was not determined.

TEST SITE
On the day before treatment the back and flanks of each animal were clipped free of hair.

Using available information on the toxicity of the test item, a group of five male and five female rats was treated with the test item at a dose level of 2246 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).

The appropriate amount of test item, moistened with distilled water, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over the treatment area and semi-occluded with a piece of self-adhesive bandage. The animals were caged individually for the 24-Hour exposure period. Shortly after dosing the dressings were examined to ensure that they were
securely in place.

REMOVAL OF TEST SUBSTANCE:
After the 24-Hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test item. The animals were returned to group housing for the remainder of the study period.
Duration of exposure:
24 hours
Doses:
2246 mg/kg (equivalent to 2000 mg active ingredient/kg bodyweight).
No. of animals per sex per dose:
5 male and 5 female at 2246 mg/kg (2000 mg ai/kg bodyweight).
Control animals:
not required
Details on study design:
- Duration of observation period following administration: 14 days

- Frequency of observations and weighing:
The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.

After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation and scored according to the Draize scale (see evaluation of skin reactions).

Any other skin reactions, if present were also recorded.

Individual bodyweights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.

- Necropsy of survivors performed: yes
At the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
act. ingr.
Remarks on result:
other: Equivalent to >1600 mg/kg bw active acid
Mortality:
Individual mortality data are given in Table 1 (see attached background material).
There were no deaths.
Clinical signs:
Individual clinical observations are given in Table 1 (see attached background material).
There were no signs of systemic toxicity.
Body weight:
Individual bodyweights and weekly bodyweight changes are given in Table 4 (see attached background material).
Animals showed expected gains in bodyweight, except for one female which showed no gain in bodyweight during the first week but expected gain in bodyweight during the second week.
Gross pathology:
Individual necropsy findings are given in Table 5 (see attached background material).
No abnormalities were noted at necropsy.
Other findings:
Dermal Reactions:
Individual dermal reactions are given in Table 2 and Table 3 (see attached background material).
There were no signs of dermal irritation.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight, equivalent to to 1600 mg/kg bw active acid).

Executive summary:

Introduction. 

The study was performed to assess the acute dermal toxicity of the test item in the Wistar strain rat. The method was designed to be compatible with the following:

- OECD Guidelines for the Testing of Chemicals No. 402 "Acute Dermal Toxicity" (adopted 24 February 1987)

- Method B3 Acute Toxicity (Dermal) of Commission Regulation (EC) No. 440/2008

-Environmental Protection Agency Health Effects Gudelines OPPTS 870.1200 Acute Dermal Toxicity August 1998

- Japanese Mistry of Agriculture, Forestry and Fisheries (MAFF), Testing Guidelines for Toxicology Studies, 12 NohSan No. 8147, amended 26 June 2001

- Japanese Ministry of Health and Welfare, 1992

 

Method. 

A group of ten animals (five males and five females) was given a single, 24 hour, semi‑occluded dermal application of the test item to intact skin at a dose level of 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight). Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

 

Mortality. 

There were no deaths.

 

Clinical Observations. 

There were no signs of systemic toxicity.

 

Dermal Irritation. 

There were no signs of dermal irritation. 

Bodyweight. 

Animals showed expected gains in bodyweight, except for one female which showed no gain in bodyweight during the first week but expected gain in bodyweight during the second week.

 

Necropsy. 

No abnormalities were noted at necropsy.

 

Conclusion. 

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2246 mg/kg bodyweight (equivalent to 2000 mg active ingredient/kg bodyweight).

 

The test item does not meet the criteria for classification according to the Globally Harmonised System of Classification and Labelling of Chemicals.