QA is quality management, QC is quality inspection, and QA is the planning, prevention, control and promotion of a company's overall quality. QC only checks and checks the products. When it comes to harm, it depends on the products you are involved in. Some products will be harmful to health, such as heat treatment inspection, which will involve radioactive substances. The chemist you mentioned is not a good position either. Generally, chemists recruited by companies must be married. You will know. Material testing will have a great impact on your health, so I suggest you choose QA if you can, which will not harm your health.