Formic acid

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study.

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)

Deviations:

no

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Formic acid

EC Number:

200-579-1

EC Name:

Formic acid

Cas Number:

64-18-6

Molecular formula:

CH2O2

IUPAC Name:

formic acid

Details on test material:

- Name of test material (as cited in study report): Ameisensäure 99%
- Analytical purity: 99%

Test animals

Species:

rat

Strain:

other: Bor: WISW

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: F. Winkelmann, 4799 Borchen, Germany
- Weight at study initiation: males 126 g, females 117 g
- Fasting period before study: 16 h prior to dosing
- Housing: 1 to 5 rats per cage in Macrolon cages
- Diet: complete diet ad libitum
- Water: free access to tap water ad libitum



ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20
- Humidity (%): 65
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 0.41 to 0.82 mL/kg bw


DOSAGE PREPARATION: undiluted

Doses:

501, 631, 794, 1000 mg/kg bw

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily observations for clinical signs; body weight was recorded before treatment, and on days 1, 7, and 14 thereafter
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

The LD50 was calculated according to Litchfield and Wilcoxon  (1949)

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

730 mg/kg bw

95% CL:

618 - 863

Remarks on result:

other: neat formic acid

Mortality:

Deaths occurred within 8 days after dosing; cf. tabulated detail information in the field “Remarks on results". The combined oral LD50 for male and female rats was 730 mg/kg bw.

Clinical signs:

other: Clinical signs were noted 30 minutes after dosing. Symptoms included  unkempt fur, hunched posture, stagger, aggressiveness, dyspnea, sedation  and ataxia, lateral and abdominal position, convulsions, bloody noses,  blood in urine. At later times hypother

Gross pathology:

Dead animals:  Hyperemia of the stomach and intestines. Mottled livers and kidneys.
Sacrificed animals:  Hyperemia of the stomach. Mottled livers and discoloration of kidneys and  pancreas

Any other information on results incl. tables

Mortality
The combined LD50 for male and female rats was 730 mg/kg bw.

=========================================================
Dose              Mortality         Death occurred 
(mg/kg bw)    (No. dead/exposed)       after    
               male       female  
---------------------------------------------------------    
 501          0/5         1/5        within 1 hour
 631          2/5         2/5        within 24 hours
 794          1/5         5/5        within 8 days
1000          4/5         4/5        within 48 hours
=========================================================

Clinical signs
Clinical signs were noted 30 minutes after dosing. Symptoms included  unkempt fur, hunched posture, stagger, aggressiveness, dyspnea, sedation  and ataxia, lateral and abdominal position, convulsions, bloody noses,  blood in urine. At later times hypothermia, body weight loss and pale  limbs were additionally noted. 
Symptoms subsided and were absent in all animals but one which showed  symptoms until the end of the observation period.

Body weight gain was decreased in a dose-related manner 

=========================================
Dose              Mean body weight gains  
(mg/kg bw)      within 14 days post dosing  
                 (g; males and females)
-----------------------------------------   
 501                56.1
 631                45.9  
 794                28.3  
1000               - 3.4
=========================================

Gross pathology
Dead animals: 
Hyperemia of the stomach and intestines. Mottled livers and kidneys.

Sacrificed animals: 
Hyperemia of the stomach. Mottled livers and discoloration of kidneys and  pancreas.