/kloc-can I apply for a health certificate at the age of 0/5?

Of course. A health certificate is a proof of a person's health. There is no age limit for obtaining a health certificate. You need to apply for a health certificate at work, but you don't need to apply for a health certificate when you are a student. You can apply for it at the age of 15. Health certificate refers to the proof of preventive health examination, which proves that the examinee has the health quality to engage in the prescribed business.