Ammonia, anhydrous

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Acute inhalation toxicity study of ammonia in rats with variable exposure periods.

Author:

Appelman, L.M., Ten Berge, W.F. and Reuzel, P.G.J.

Year:

1982

Bibliographic source:

Am. Ind. Hyg. Assoc. J; 43(9), 1982, 662-665.

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Assessment of acute inhalation toxicity in the rat following various exposure periods

GLP compliance:

not specified

Remarks:

: published study

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ammonia, anhydrous

EC Number:

231-635-3

EC Name:

Ammonia, anhydrous

Cas Number:

7664-41-7

Molecular formula:

H3N

IUPAC Name:

ammonia

Details on test material:

Liquid ammonia (UKF-SBB, Geleen, The Netherlands), supplied in a pressurised container.

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Groups of male and female SPF-bred Wistar rats (Cpb:WU, Wistar Random), obtained from the Central Institute for the Breeding of Laboratory Animals, TNO, Zeist. The average age of the rats on arrival was 7-8 weeks, and the body weights of males and females varied between 150-170 g, and 130-140 g, respectively. After exposure rats were housed 5 per cage for the 14 day observation period. Food (standard laboratory rat diet) and tap water were available during the observation period, but were witheld during exposure. The temperature and relative humidity of the room were maintained at 21±1°C and 50-60%, respectively.

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

Groups of male and female rats were exposed to dynamic atmospheres containing different concentrations of ammonia for 10, 20, 40 or 60 mins. The atmosphere was an ammonia/air mixture, introduced at a rate of 25 L/min.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by titration

Duration of exposure:

10 - 60 min

Concentrations:

Various exposure concentrations were used to establish the LC50 value for ammonia at 10, 20, 40 or 60 mins. Actual range of concentrations used not noted.

No. of animals per sex per dose:

5 males and 5 females per group

Control animals:

no

Details on study design:

Groups of female and male rats were exposed to dynamic atmospheres containing different concentrations of ammonia for 10, 20, 40 or 60 mins. The aim of the study was to establish the relationship between exposure concentration and exposure period and mortality. Following exposure rats observed for clinical signs for 14 days. Body weight was recorded at days 1, 2, 4, 7, and 14. Clinical symptoms were recorded, and autopsy was performed after the 14 day observation period.

Statistics:

Probit method used to calculate LC50 values

Results and discussion

Preliminary study:

A preliminary study was not reported

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

28 130 mg/m³ air

95% CL:

26 040 - 30 380

Exp. duration:

10 min

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

19 960 mg/m³ air

95% CL:

19 050 - 20 920

Exp. duration:

20 min

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

14 170 mg/m³ air

95% CL:

13 500 - 14 870

Exp. duration:

40 min

Effect levels 4

Sex:

male/female

Dose descriptor:

LC50

Effect level:

11 590 mg/m³ air

95% CL:

10 860 - 12 380

Exp. duration:

60 min

Effect levels 5

Sex:

male

Dose descriptor:

LC50

Effect level:

9 850 mg/m³ air

95% CL:

8 490 - 11 430

Exp. duration:

60 min

Effect levels 6

Sex:

female

Dose descriptor:

LC50

Effect level:

13 770 mg/m³ air

95% CL:

12 350 - 15 340

Exp. duration:

60 min

Mortality:

Mortality data are presented in Table 1.

Clinical signs:

other: Eye-irritation; especially in animals exposed for 60 minutes, wet noses, nasal discharge, mouth breathing, restlessness and laboured respiration were seen during exposure.

Body weight:

Not reported

Gross pathology:

Macroscopic examination revealed haemorrhagic lungs in animals that died during the study and also those that were sacrificed at study termination.

Other findings:

No other findings

Any other information on results incl. tables

Table 1. Mortality Data

Ammonia Concentration (mg/m³ air)	Exposure time (min)	Mortality rate (%)
		Males	Females	Both Sexes Combined
20950	10	0	0	0
23380		20	0	10
26410		100	20	60
27220		100	0	50
37820		100	80	90
18290	20	60	0	30
19030		20	0	10
19450		100	40	70
21420		60	60	60
23200		100	80	90
12620	40	40	0	20
13410		80	20	50
15870		80	20	50
16290		100	60	80
16840		100	40	70
9870	60	40	20	30
10230		80	0	40
11300		100	0	50
12500		100	20	60
13240		100	40	70

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

As the exposure period increased, the LC50 decreased in value from 28130 mg

Executive summary:

The acute inhalation toxicity of ammonia was assessed by exposing groups of male and female Wistar rats were to atmospheric ammonia for 10, 20, 40 or 60 minutes. Following exposure surviving rats were housed 5 per cage and observed for 14 days.

Clinical symptoms included eye irritation, wet noses and nasal discharge. Autopsy revealed haemorrhagic lungs. The 60 minute LC50 in male rats was 9850 mg/m³ air. The 60 minute LC50 in female rats was 13770 mg/m³ air.