Fig. 4 Comparison of the concentration of toxic substances in the workplace air with the standard value (TWA)
Figure 5 STEL in workplace air compared with standard values â€‹â€‹(STEL)
3 Discussion The qualitative analysis results of volatile toxic substances in inks and adhesives are inconsistent with the test results in the workplace. Qualitative analysis of toxic substances detected in the workplace may not be detected; qualitative analysis of undetected toxic substances may be detected in the workplace. On the one hand, it may be the workplace environment is complex and there are many influencing factors. On the other hand, it can not fully guide the detection of toxic substances in the air of the workplace with the qualitative analysis results of mass spectrometry. Therefore, the mass spectrometry of the ink and adhesive in the actual work and workplace air Toxic substances in the gas chromatographic examination should cooperate with each other.
Qualitative analysis did not detect toxic substances in Taiyuan Offset rotary printing ink, the use of toxic substances in the workplace detected benzene, toluene, xylene, ethyl acetate and solvent gasoline concentrations are lower, and their TWA values â€‹â€‹are in the standard value of hygiene Below 4%, STEL values â€‹â€‹are below 6% of the sanitary standard value. In combination with occupational hygiene surveys, excluding the effects of changes in production processes and other toxic substances contamination, the qualitative results of mass spectrometry have certain guiding significance for health supervision and hygiene evaluation work. When qualitative analysis of mass spectrometry is not detected, even if toxic substances are detected in the air of the workplace, its concentration will not exceed the standard.
The qualitative analysis of Tianjin Jingying brand printing inks detected the toxic substances 2-butanone, isopropanol, xylene and 2-butanone oxime, while the use of butanone and xylene in the workplace air was not detected. The concentration of propanol is lower than the minimum detection concentration; the qualitative analysis of 7013 rubber detects vinyl acetate, a toxic substance, and it is higher than the hygienic standard for vinyl acetate in the air of the place, which may be a high temperature for the film production process (about 60-70Â°C). , Volatilization caused by a large amount of vinyl acetate. This result suggests that if the temperature at the qualitative detection is consistent with the production process temperature, the result may be more scientific.
A total of 4 toxic substances were detected in the qualitative fingerprint printing ink produced in Tianjin. The 2-methylbutanone with the highest peak area in the mass spectrometric total ion chromatogram was not detected in the air of the workplace, but the peak area followed by isopropyl was detected. alcohol. Therefore, the size of the peak area is difficult to determine the concentration of the air in the site, which may be the actual production process conditions are not completely consistent with the conditions of the qualitative analysis of the experimental environment.
Source: Print Chemicals Network
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