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Diss Factsheets

Administrative data

Endpoint:
health surveillance data
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Published study

Data source

Reference
Reference Type:
publication
Title:
Acute and chronic respiratory effects of occupational exposure to ammonia
Author:
Holness, D.G., Purdham, J.T., Nethercott, J.R.
Year:
1989
Bibliographic source:
American Industrial Hygiene Association Journal, 50(12):646-650

Materials and methods

Study type:
medical screening
Endpoint addressed:
repeated dose toxicity: inhalation
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The chronic effects of ammonia inhalation on industrial workers were examined
GLP compliance:
not specified
Remarks:
: not applicable to this type of study

Test material

Constituent 1
Chemical structure
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:
Ammonia, used in the production of sodium carbonate using the Solvvay process.

Method

Type of population:
occupational
Ethical approval:
not specified
Details on study design:
The results of an investigation in which the chronic effects of ammonia (7664417) on industrial workers exposed to levels less than 50 parts per million (ppm) were assessed. The acute effects of ammonia exposure on the respiratory and integumentary systems of these workers was also examined. The workers were exposed in the production of sodium-carbonate (497198) (soda-ash) using the Solvay process. Fifty two of the available 64 workers agreed to participate. These workers were assessed on the first workday of the work week and on the last workday of the same week. A comparison group consisted of 31 workers with a mean exposure of 0.3 to 0.1ppm ammonia.

Results and discussion

Results:
The exposed workers and comparisons experienced ammonia levels of 9.2 and 0.3ppm, respectively. Three workers were noted to have time weighted average ammonia concentrations in excess of 25ppm. There were no differences between the two groups in the reporting of respiratory or cutaneous symptoms, sense of smell, baseline lung function, or change in lung function over a work shift at the beginning and end of a work week. No relationships were observed between level or length of ammonia exposure and lung function results.

Any other information on results incl. tables

There were no differences in symptoms, sense of smell, acute changes in lung function during exposure, or changes in baseline lung function in exposed workers compared to control workers. There was no relationship demonstrated between the level of exposure to ammonia (average of 9.2 ppm (= 6.4 mg/m3) and acute changes in lung function over the work shift. No chronic effects on lung function that could be related to the length of exposure were demonstrated.

The chronic effects of ammonia on industrial workers to levels less than 50 ppm were assessed.  The study also examined the acute effects of ammonia exposure on the respiratory system, eyes, and skin. A total of 52 soda ash plant workers, 6 maintenance workers, and 35 control workers were assessed. All participants were male, mean age 40.5 years, and plant tenure approximately 15 years. Exposed workers were assessed on 2 workdays; on the first and last workdays of their workweek. The study was carried out over a period of one week. Maintenance workers were assessed on one workday in the middle of their workweek. The control group was assessed twice on two separate days during the same week. All participants completed a questionnaire regarding past occupational exposures, working conditions, smoking history, and respiratory symptoms and eye and skin complaints. Each participant's sense of smell was assessed at the beginning and end of the workweek. Spriometry was performed at the beginning and end of each work shift on both test days so that each worker had four tests done. The average concentration of ammonia to which workers were exposed during their work shifts was determined using NIOSH-recommended procedures. Exposed and control workers were sampled over one work shift. The average sample collection period was 8.4 hours. The mean time-weighted average (TWA) ammonia exposure of the exposed group was 9.2 ppm, 0.3 ppm for the control group.  Three workers were exposed to TWA concentrations in excess of 25 ppm.

 

Applicant's summary and conclusion

Conclusions:
No adverse health effects are reported in workers exposed to ammonia at concentrations (TWA) of up to 25 ppm and higher.
 
Executive summary:

The chronic effects of ammonia inhalation on industrial workers were examined. The exposed workers and comparisons experienced ammonia levels of 9.2 and 0.3 ppm, respectively. Three workers were noted to have time weighted average ammonia concentrations in excess of 25ppm. There were no differences between the two groups in the reporting of respiratory or cutaneous symptoms, sense of smell, baseline lung function, or change in lung function over a work shift at the beginning and end of a work week. No relationships were observed between level or length of ammonia exposure and lung function results.

It is therefore concluded that exposure to ammonia at concentrations of up to 25 ppm is without adverse effects.