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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
GLP compliance:
yes (incl. QA statement)
Test type:
acute toxic class method
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
Diethyl ethylphosphonate
EC Number:
EC Name:
Diethyl ethylphosphonate
Cas Number:
Molecular formula:
diethyl phosphonate
Test material form:

Test animals

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 under the conditions 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 3 animals per cage in a room equipped with central air-conditioning. The average room temperature was maintained within the range of 23.26 ± 0.17° C, relative humidity within 53.29 ± 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

Route of administration:
oral: gavage
olive oil
Details on oral exposure:
The test item was administered in a single dose by gavage using a metal stomach tube. Animals were fasted prior to dosing (food but not water were withheld over-night). Following the period of fasting, the animals were weighted and the test item was administered. After test item administration, food was withheld for further 3-4 hours.
5, 50, 300, and 2000 mg/kg body weigh
No. of animals per sex per dose:
One group of 3 females was dosed. Test item-related mortality was observed during the first 4 hours. In a second step 3 females were treated at the dose of 300mg/kg body weight. All females survived 24 hours and therefore another 3 females (third step) were treated at the same dose of 300 mg/kg body weight.

Results and discussion

Effect levels
Dose descriptor:
Effect level:
> 300 - < 2 000 mg/kg bw
Based on:
test mat.
Mortality of 3/3 females at limit dose of 2000 mg/kg body weight was noted. All 6/6 females survived the dose of 300 mg/kg body weight.
Clinical signs:
other: Test item-related mortality in females treated with the test item in dose of 2000 mg/kg body weight was observed within the first 4 hours. Lethargy was observed in all 3 animals (No 1, 2, 3), in animal No 1 immediately after administration of the test ite
Gross pathology:
All animals were necropsied. During necropsy, no macroscopic findings were observed.

Applicant's summary and conclusion

Interpretation of results:
Category 4 based on GHS criteria
The LD50 of the test item Diethyl ethylphosphonate is higher than 300 mg/kg body weight and lower than 2000 mg/kg body weight after single oral administration to Wistar rats.
Based on Annex 2d Test Procedure with a Starting Dose of 2000 mg/kg body weight of OECD Guideline 423 it can be concluded that the test item Diethyl ethylphosphonate is classified in Category 4 with a LD50 cut off value 2000 mg/kg body weight, after single oral administration to Wistar rats.