Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted May 1981

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate

EC Number:

282-810-6

EC Name:

Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate

Cas Number:

84434-11-7

Molecular formula:

C18H21O3P

IUPAC Name:

ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate

Details on test material:

- Name of test material (as cited in study report): Initiator 654
- Physical state: liquid
- Purity: > 97%
- Expiration date of the lot/batch: Feb. 1983

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Acclimatization period: at least one week.
Age of animals at beginning of study: About 12 weeks
Type of cage: Type DK-III stainless steel wire mesh cages
Number of animals per cage: 5
Animal identification: Identification of groups using cage cards
Room temperature: 20 - 26°C
Relative humidity: 45 - 75%
Air changes: 15 - 20 /hour
Day/night rhythm: 12 h/12 h (6.00 - 18.00 hours/18.00 - 6.00 hours)
Drinking water: Fully demineralized water each workday, ad libitum; tap water on public holidays, ad libitum
Diet: SSNIFF R; Ssniff Versuchstierdiäten, Soest, FRG
Fasting period: 16 hours before administration, water available ad libitum

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5% in water

Details on oral exposure:

Preparation with 0.5% aqueous carboxymethyl cellulose
Reason for the vehicle: Aqueous formulation corresponds to the physiological medium
Form of administration: Emulsion
Concentrations used: 26.1, 38.3, 50% (w/v)
Application volume: 10 ml/kg

Doses:

2610, 3830, 5000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Observation period: 14 days
Weight check: Animals of comparable weights (± 20 g) in one cage.
Cageside observation: Recording of signs and symptoms < 15', 15', 30', 1 h, 2 h, 4 h, and 5 h after administration of test substance and then once each workday. Check for moribund and dead animals twice each workday and once daily at weekends and on public holidays.
Pathology: Withdrawal of feed 16 hours before sacrifice with CO2, followed by necropsy and gross-pathological examination. All animals that die are necropsied as early as possible.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Remarks on result:

other: Mortality occurred at all dose levels (2160, 3830 and 5000 mg/kg )

Mortality:

Males: 5000 mg/kg 1/5 after 1 day, no mortality at other dose levels
Females: 5000 and 2610 mg/kg: 2/5 after 1 day, 3830 mg/kg: 1/5 after 1 day

Clinical signs:

other: Male animals: All dose groups showed dyspnea, apathy, staggering, twitching, piloerection (not observed for high dose males), and poor general state. Abnormal position, tonus with bending, tonic-clonic convulsions, salivation, and fasciculation were obs

Gross pathology:

Animals that died (female): Stomach: Bloody erosions in the region of the glandular stomach in 1 animal; liver: grayish-white to clay-colored periphery involving a minimum part of the acinus.
Sacrificed animals (male & female): Organs: No abnormalities detected.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the study, the acute oral LD50 of the registered substance was found to be >5000 mg/kg bw in the rat.

Executive summary:

Males were less sensitive than females. Doses of 2160, 3830 and 5000 mg/kg bw were tested. In females, 2 of 5 animals each died at 2160 and 5000 mg/kg bw within the first day of dosing. In the mid dose, one female died. One high dose male died, but no mortality was observed in the remaining dose groups. In the females that died, bloody erosions in the region of the glandular stomach occurred in 1 animal. In the liver, grayish-white to clay-colored periphery involving a minimum part of the acinus was observed. No findings were observed in surviving animals.