Are the quality manual and the environmental occupational health and safety management manual written separately or merged into one manual?

This depends on whether the enterprise is certified by three systems together or separately. The combined certification will be compiled into a manual, while the individual certification will be compiled into a manual. According to my experience, three-in-one certification has great advantages. For example, management review, internal review and external review can be completed at one time, which can greatly save resources and time. If the certification is carried out separately, each system shall do it at least once a year for a total of three times.