Registration Dossier

Toxicological information

Exposure related observations in humans: other data

Currently viewing:

Administrative data

Endpoint:
exposure-related observations in humans: other data
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1974-1977
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Public available literature with good scientific documentation.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Evaluation and control of a respiratory exposure to 3-(dimethylamino)proplyamine
Author:
Brubaker, R.E.., Muranko, H.J., Smith, D.B., Beck, G.J., Scovel, G.
Year:
1979
Bibliographic source:
J. Occupat. Med., 21 (No.10):688-690
Reference Type:
publication
Title:
Respiratory effects of occupational exposure to an epoxy resin system
Author:
Sargent, E.V., Mitchell C.A., Brubaker R.E.
Year:
1976
Bibliographic source:
Arch. Environ. Health, 31:236-240

Materials and methods

Type of study / information:
Worker exposure study (respiratory irritation)
Endpoint addressed:
respiratory irritation
respiratory sensitisation
Test guideline
Qualifier:
no guideline required
Principles of method if other than guideline:
Occupational case study.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Method

Ethical approval:
not specified
Details on study design:
1974 Study:
34 subjects, 25 mold room workers and nine controls, were administered a questionnaire which included smoking and occupational histories and specific inquiries in regard to work-related upper and lower respiratory symptoms. None of the controls had any complaints, while 10 of the mold room workers had upper respiratory symptoms and 11 reported a total of 20 lower respiratory complaints, including cough and increased phlegm, wheezing, and chest tightness.
Pulmonary function tests were performed before and after the workshift on Monday and Thursday. Each subject worked one 10-hour shift, 6:30 a.m. to 5:30 p.m., Monday through Thursday.

The 34 subjects were divided for analysis into four sub-groups:
controls (N = 9)
assemblers (N = 7)
pressmen (N = 8)
other mold room workers (N = 10)

1977 Study:
The 1977 study was one of a series of cross-sectional studies of the mold room begun in 1974 for the purpose of determining the effectiveness of ventilation improvements in reducing the level of DMAPA and in eliminating the decrease in pulmonary function over the workshift.

Methods
Environmental Measurements:
Multiple samples were taken at the breathing zones of assemblers since previous studies had shown that this sub-group was subject to the highest concentration of DMAPA.
Study Population and Examination
34 subjects participated in the study. For analysis they were divided into five sub-groups:
non-exposed controls from office areas (N = 6)
assemblers (N = 8)
gluers (N = 6)
pressmen (N = 8)
other mold room workers (N = 6)

All subjects worked a 10-hour shift from 6:30 a.m. to 5:30 p.m. It should be noted that only four of the workers who participated in the 1974 study were employed in the mold room in 1977. The examination included two parts. The first part consisted of a respiratory questionnaire which had been used in each of the cross-sectional studies since 1974 and which included smoking and occupational histories and specific inquiries as to work-related respiratory symptoms. The second part consisted of pulmonary function tests which were administered to each subject before and after the Monday workshift. Spirograms were obtained with a Collins nine-liter water-sealed spirometer and the forced vital capacity (FVC), the forced expiratory volume in one second (FEV1), the forced mid-expiratory flow (FEF 25-75%), and the forced end-expiratory flow (FEF 75-85%) were recorded. The techniques of administering the tests and of measuring spirometer variables followed the recommendations of the Snowbird Workshop
Exposure assessment:
measured
Details on exposure:
TYPE OF EXPOSURE: Occupational exposure during the years 1974 - 1977

TYPE OF EXPOSURE MEASUREMENT:
1974 and 1977study:
Measured area and breathing zone concentrations of total primary aliphatic amines using a spectrophotometric method for determination of total aliphatic amines in air. The samples and the bulk hardener were qualitatively analyzed with infrared spectroscopy.

EXPOSURE LEVELS:
1974 study:
Environmental measurements of the total amine levels were found to range from 0.41 to 1.38 ppm

EXPOSURE PERIOD:
1974 study:
Time-weighted average concentrations for 8-hour exposures to the amines
1977 study:
Time-weighted average concentrations for 10-hour work shift

POSTEXPOSURE PERIOD: none

DESCRIPTION / DELINEATION OF EXPOSURE GROUPS / CATEGORIES:
1974 study:
The 34 subjects were divided for analysis into four sub-groups:
controls (N = 9)
assemblers (N = 7)
pressmen (N = 8)
other mold room workers (N = 10)

1977 Study:
34 subjects participated in the study. For analysis they were divided into five sub-groups:
non-exposed controls from office areas (N = 6)
assemblers (N = 8)
gluers (N = 6)
pressmen (N = 8)
other mold room workers (N = 6)

Results and discussion

Results:
1974 study:
It was found that the assemblers, who had the highest average exposure (0.9 ppm), had the highest prevalence of symptoms and a significant decrease in lung function over Monday and over the week compared to Monday morning values. In the controls, the forced vital capacity (FVC), the forced expiratory volume in one second (FEV1), the mid-expiratory flow (Vmax 50%), and the end-expiratory flow (Vmax75%) increased significantly (p < 0.05 for all comparisons with Monday morning values), while in the assemblers all measurements decreased significantly over the same period (p < 0.05 for all comparisons with Monday morning values). The lung function of the pressmen and the other mold room workers was intermediate between that of the assemblers and the controls but showed no significant changes over Monday and over the week. It was recommended that airborne 3-DMAPA be reduced to a no-effect level, and it was suggested that a level between 0.41 and 0.55 ppm would be an acceptable 10-hour time weighted average exposure.

1977 study:
Environmental Measurements:
The average breathing zone concentration of the assemblers was 0.13 ppm. This was a reduction to nearly one-seventh of the average level of 0.9 ppm in 1974

Questionnaire:
None of the control group reported respiratory complaints. Five of the 28 mold room workers reported nasal irritation and two reported increased phlegm. There were no other lower respiratory symptoms. In contrast, in 1974, at the higher level of 3-DMAPA, 44% of the workers had one or more work-related complaints of cough with increased phlegm, wheezing, and tightness in the chest.

Lung Function Before and After the Workshift:
The control group had a significant increase over the day only in FEF 25-75% (p = 0.03). In contrast to 1974, the assemblers' function no longer decreased significantly over the workshift. The mid- and end-expiratory flows actually increased (p = 0.03 for FEF 25-7S% and p = 0.01 for FEF 75-85 %). The pressman, as before, showed no significant change over the day in any lung function with the only decrease occurring in the FVC (p = 0.07). Other significant changes over the Monday workshift (not shown) were in the "other mold room workers" sub-group, in which the FVC decreased to 96.1% of the before-shift value while the FEV1 and the FEF 25% increased. Comparison of lung function changes over the workshift among all five worker groups with an analysis of variance showed no significant group dif¬ferences in any function.

Applicant's summary and conclusion