Phenacetin

Endpoint summary

Description of key information

Key study: Acute oral toxicity. The LD50 value of the test item is 1650 mg/ kg body weight by oral route in rat.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1959

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

The method employed has been described by Boyd (1959). The method described in this report was designed to evaluate the clinical and pathological signs of intoxication in animals following oral administration of phenacetin in doses within the range of the median lethal dose.

GLP compliance:

not specified

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: not specified.
- Age at study initiation: 3-6 months.
- Weight at study initiation: 220 ± 21 g body weight.
- Housing: each rat was placed singly in a metabolism cage and food (Purina fox chow checkers) withheld overnight.

Route of administration:

other: Suspension was administered into the stomach

Vehicle:

other: Distilled water,

Details on oral exposure:

DOSAGE PREPARATION
Phenacetin, BP (Acetophenetidin, USP) was freshly prepared as a suspension in distilled water, with gum tragacanth (0.25&) as suspending agent.

ADMINISTRATION
The suspension was administered into the stomach in a volume of 2.0 ml per 100 g body weight. The doses of phenacetin expressed as grams per kilogram body weight, and, in parentheses, number of rats per dose were: 0.00 ( 11) .’ 1.00 (lo)1.30 (13), 1.50 (8), 1.75 (8), 2.00 (16).

Doses:

0, 1, 1.3, 1.5, 1.75, 2.0 g/kg b.w.

No. of animals per sex per dose:

Females: 0.00 ( 11) .’ 1.00 (10)1.30 (13), 1.50 (8), 1.75 (8), 2.00 (16).

Control animals:

yes

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

1 650 mg/kg bw

Based on:

test mat.

Mortality:

Mortality was observed due to respiratory failure in marked hypothermia at 22.8 ± 17.7 (mean ± S.D.).

Clinical signs:

other:

Gross pathology:

At autopsy.

Interpretation of results:

other: Category 4 (CLP Regulations EC no. 1272/2008)

Conclusions:

The LD50 value of the test item is 1650 mg/ kg body weight by oral route in rat.

Executive summary:

The acute oral toxicity of the test item has been tested following method described by Boyd1959. 66 female rats were administered into the stomach in a volume of 2.0 mL per 100 g body weight. The median lethal dose plus or minus standard error was calculated to be 1.65 ± 0.35 g per kilogram body weight. Death ocurred in 22.8 ± 17.7 hours after drug administration and clinical signs were evident 2-4 hours after administration of phenacetin in the dose employed. At the experimental conditions tested, test item is considered to be harmful if swallowed (Category 4).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 650 mg/kg bw

Quality of whole database:

The study has a Klimisch score of 2.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the available information, the substance is classified as Category 4 for acute toxicity in accordance with CLP Regulation (EC) No 1272/2008.