Table 6.

Recommendations to minimize the risk of exposure to gallium arsenide

Recommendations	Contents
Awareness of risk	The development of policies for the proper handling of gallium arsenide should be developed and implemented by health and safety personnel, and workers should be trained to be aware of the risks associated with gallium arsenide, and to make appropriate work practices and available engineering improvements. Workers should regularly collect samples from work areas that are likely to be exposed to gallium arsenide particles, or where surfaces are likely to be contaminated, which include crystal growth, crystal puller cleaning, crystal sawing, wafer grinding, and dicing. The sample should be analyzed for inorganic arsenic, and the analysis method described in NIOSH Analysis Method Manual, Method No. 7900 (NIOSH 1984) is used, and in some areas of the gallium arsenide process, both arsenic and gallium arsenic particles may be present
Engineering control and improvement of work practices	Recommendations for engineering controls and work practices are aimed at reducing gallium arsenic and arsenic exposure in the production area of gallium arsenide semiconductor manufacturing
PPE	Workers must provide and use disposable protective clothing, gloves, foot covers, and other suitable protective equipment necessary to prevent skin contact with gallium arsenide particulates. This protective device should be worn in the case of exposure to the crystal puller, crystal growth ampoule failure, and other gallium arsenide particles, and engineering controls are the preferred method to protect workers from exposure to gallium arsenide and arsenic, but NIOSH Respirators are also needed to protect workers in certain situations, such as emergencies involving the implementation, maintenance, and repair of engineering controls. Where engineering controls cannot adequately reduce exposures below REL to arsenic, workers should be provided with adequate respirators. If respiratory protection is required, employers must initiate a respiratory protection program that meets the OSHA requirements specified in 29 CFR 1910.134 (OSHA 2006), and a respiratory protection program approved by the Mines Safety and Health Administration (MSHA) and NIOSH includes at least respiratory. Assessment of workers’ ability to perform tasks while wearing them, personnel training, suitability testing, and periodic environmental monitoring are included, and maintenance, inspection, and respiratory cleaning are also included. To implement an appropriate respiratory protection program, including the selection of the correct respiratory system, a knowledgeable person should be in charge of the program, and regularly evaluate the program. NIOSH recommends using only the most reliable respirators to protect workers from exposure to carcinogens. The following respirator is recommended for such a ventilator consisting of a supply air, front panel, and positive pressure ventilator with self-contained breathing apparatus. A combination of a full-face self-contained breathing apparatus or a full-face ventilator that operates in a pressure-demanding mode and a pressure-operated auxiliary self-contained breathing apparatus are recommended
Decontamination and waste disposal	If gallium arsenic or arsenic can be removed from contaminated equipment, decontamination procedures should be established and performed. Where decontamination is not possible, the removal, transportation, and disposal of substances contaminated with gallium arsenide or arsenic must be in accordance with the regulations of the U.S. EPA, U.S. Department of Transportation, and/or state and local authorities. According to Negrei and Galateanu (2019), it is important to differentiate between workers with higher risk and lower risk, screening for both higher and lower risk is cost-effective, and it is also important to increase the level of participation by improving workers’ awareness
Molecular diagnosis in everyday life test: Use of liquid biopsy	Strict medical surveillance of and various precautions against mutants susceptible to cancer must be taken, and cancers resulting from gonadal mutations often require significant modification of treatment strategies. The selection of customized anticancer drugs based on the potential for mutations has become an essential factor in cancer treatment, and molecular analysis is based on the administration of EGFR, BRAF, ALK, ROS1, and PARP inhibitors, as well as the use of other cytotoxic and target drugs. Liquid biopsies, i.e., analysis of circulating DNA or other tumor-derived molecules, offer great potential for the non-invasive monitoring of cancer diseases, drug-sensitive mutation analysis, and early cancer detection, while some tumor or tissue-specific mutant biomarkers that are used to diagnose primary cancer can be effectively utilized. The systematic classification of tumor molecular biomarkers increases the likelihood of discovering numerous new DNA and RNA-based markers of medical relevance