5-methyl-s-triazolo[1,5-a]pyrimidin-7-ol

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 February 1985 to 09 April 1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

test according to OECD 401 under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

12 May 1981

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

5-methyl-s-triazolo[1,5-a]pyrimidin-7-ol

EC Number:

219-706-7

EC Name:

5-methyl-s-triazolo[1,5-a]pyrimidin-7-ol

Cas Number:

2503-56-2

Molecular formula:

C6H6N4O

IUPAC Name:

5-methyl-s-triazolo[1,5-a]pyrimidin-7-ol

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Central Institute for Breeding of Laboratory Animals TNO (CPB), Zeist, The Netherlands
- Females (if applicable) nulliparous and non-pregnant: no data
- Age at study initiation: no data
- Weight at study initiation: males 205-231 g; females 145-160 g
- Fasting period before study: yes (overnight until 3-4 hours after dosing)
- Housing: individually in macrolon cages
- Diet: standard pelleted lab feed (RMH, Hope Farms) ad libitum
- Water: tap water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22 °C
- Humidity (%): 50-65%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

VEHICLE: arachis oil

MAXIMUM DOSE VOLUME APPLIED: 12.5 mL/kg

DOSAGE PREPARATION (if unusual): ultrasonicated for 3.75 hours (suspension)

Rationale for the selection of the doses: pre-test in 2 males/2 females at 4000 mg/kg bw (maximum achievable dose) based on information by sponsor --> no deaths

Doses:

4000 mg/kg bw

No. of animals per sex per dose:

5 males + 5 females per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: frequency not indicated for mortality and clinical signs
- Frequency of weighing: on day 0, 7 and 14
- Necropsy of survivors performed: yes

Statistics:

NA LD50 value according to Finney (1971)

Results and discussion

Preliminary study:

pre-test in 1 male/1 female per group at 13, 18, 24 and 32 mg/kg bw --> no deaths
additional pre-test in 1 male/1 female per group at 1300, 2400 and 3200 (male only) --> all dead within 4 days.

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 4 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality observed

Clinical signs:

other: no signs of systemic toxicity

Gross pathology:

no macroscopic abnomalities

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 is > 4000 mg/kg bw

Executive summary:

Five rats per sex received a single dose of 4000 mg/kg bw by gavage. During the 14 day observation period no mortality, systemic toxicity, effects on body weight (gain) or macroscopic abnomalities were observed.

Based on these findings it is concluded that the LD50 is >4000 mg/kg bw (males and females combined).