Methyl hydrogen octadecylphosphonate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 1, 2005 to September 15 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Remarks:

There were no deviations reported

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

Methyl hydrogen octadecylphosphonate

EC Number:

246-905-6

EC Name:

Methyl hydrogen octadecylphosphonate

Cas Number:

25371-55-5

Molecular formula:

C19H41O3P

IUPAC Name:

methoxy(octadecyl)phosphinic acid

impurity 1

Reference substance name:

Octadecylphosphonic acid

EC Number:

225-216-4

EC Name:

Octadecylphosphonic acid

Cas Number:

4724-47-4

Molecular formula:

C18H39O3P

IUPAC Name:

octadecylphosphonic acid

impurity 2

Reference substance name:

Dimethyl octadecylphosphonate

EC Number:

246-904-0

EC Name:

Dimethyl octadecylphosphonate

Cas Number:

25371-54-4

Molecular formula:

C20H43O3P

IUPAC Name:

dimethyl octadecylphosphonate

Test material form:

solid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Five male and five female Sprague-Dawley CD strain rats were used in this study. All females were nulliparous and non-pregnant. At the start of the study the animals weighed at least 200 grams were betwen 8 to ten weeks of age. The weight variation did no exceed ±20% of the mean weight for each sex.The animals were housed in suspended solid-floor polypropylene cages furnished with wood flakes. The animals were housed individually during teh 24- hour exposure period and in groups of five, by sex, for the remained of the study. Free access to mains drinking water and food was allowed throughout the study.Environmental ConditionsTemperature: 19-25° CRelative Humidity 30-70%Light cycle: 12-hour light/ 12-hour dark cycleRoom ventilation: At least 15 air changes/hour

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Animals were exposed to the test substance for a total of 24 hours. Animals were observed for death or overt signs of toxicity 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 animals/sex/dose

Control animals:

not required

Details on study design:

On the day before treatment the backs and flanks of each animal were clipped free of hair. The test substance was applied as evenly as possible to an are of shorn skin (approximately 10% of the total body surface area). A piece of surgical gauze was placed over thet reatment area and semi-occluded witha piece fo self adhesive bandage. The animals were caged individually for the 24-hour exposure period. After the 24 hour contact period the bandage was carefullt removed and surrounding hair wiped with cotton wool and moistened with arachis oil BP to remove any residual test material. The animals were returned to group housing for the remainder of the study period. The animals were observed for deaths or overt signs of toxicity 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

No mortalities occured during the duration of the study

Clinical signs:

No clinical signs of toxicity occured during the duration of the study.

Body weight:

All animals showed expected gains in body weight over the study period.

Gross pathology:

No abnormalities wre noted at necropsy.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of this study the LD50 value of Phosphonic acid, octadecyl,-monomethyl ester is considered to be > 2000 mg/kg body weight

Executive summary:

A group of ten animals (five males and five females) was given a single, 24 -hour, semi-occluded dermal application of the test material to intacy skin at dose evels of 2000 mg/kg bodyweight. Clinical sings and bodyweight development were monitored during the study. all animals were subjected to gross necropsy. There were no unscheduled deaths od clinical signs of toxicity observed during the study. Very slight erythema was noted at all treatment sites one to four days after treatment. No abnormalities were noted at necropsy.

The acute dermal medial lethal dose (LD50) of the test material in the Sprague-Dawly CD chain was found to be greater than 2000 mg/kg bodyweight.