Diethyl ethylphosphonate

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

Diethyl ethylphosphonate

EC Number:

201-111-9

EC Name:

Diethyl ethylphosphonate

Cas Number:

78-38-6

Molecular formula:

C6H15O3P

IUPAC Name:

diethyl phosphonate

Test material form:

liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Age at First Dose 8-12 weeks; female animals were non-pregnant and nulliparous
Animal Health The health condition of animals was examined by a veterinarian before initiation of the study.
Acclimation The animals were acclimated to the condition identical to the conditions during the experiment 5 days prior to the start of treatment. The acclimation was according to the standard operation procedure.
Housing Condition The animals were housed in plastic cages suspended on stainless steel racks, up to 2-3 animals per cage, males and females separately in a room equipped with central air-conditioning. The average room temperature was maintained within the range of 23.27 ± 0.17 °C, relative humidity within 53.27 ± 1.86 %. The light regimen was set to a 12-hour light /12-hour dark cycle. The sanitation was performed according to the standard operation procedures.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Approximately 24 hours before the test, fur was removed from the dorsal area of the trunk of the test animals by clipping and shaving. A precise amount of the test item was aspirated into an adjustable pipette and applied directly on the shaved skin of the back in a single dose uniformly over an area approximately 10 % of the total body surface area. Test item was held in contact with the skin by using semi-occlusive dressing with non-irritating tape throughout the 24-hours exposure period. At the end of the exposure period, any residuals of the test item were removed by using lukewarm water without altering the existing response or integrity of the epidermis.

Duration of exposure:

24-hours exposure

Doses:

50, 200, 1000, and 2000 mg/kg body weight

No. of animals per sex per dose:

5 males and 5 females

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Clinical signs:

other: Animals were observed individually immediately after the application of the test item and then 0.5, 1, 2, and 4 hours later. Then each animal was inspected daily for the next 14 days. Observations included changes in skin and fur, eyes and mucous membran

Other findings:

All test animals were subjected to gross necropsy. Full, detailed gross necropsy included careful examination of external surface of the body, all orifices, and cranial, thoracic and abdominal cavities and their contents. All gross pathological changes were recorded for each animal.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on OECD Guideline 402 and OECD Guideline Draft 434 it can be concluded, that for the test item Diethyl ethylphosphonate according to the Globally Harmonised System and Category Labelling of Chemicals can be classified in Category 5/Unclassified with LD50 value greater than 2000 mg/kg body weight after single dermal application to Wistar rats.