If you have employees, you're governed by OSHA or your particular State's version of OSHA, and any individual State version of workplace safety rules has to be at least equal to OSHA requirements.
During a recent visit we were told us our safety manual should be about 15-16 pages, covering only the things that would be considered hazardous to employees. They've learned that the bigger the manual, the less likely anyone knows what it says, and the less likely anyone complies with anything. A bigger manual also allows you to be in violation of more stuff. You get a small fine for something left out, and walloping big fines for not complying with everything in your safety program.
They told me to throw out the 500 page manual our insurance company provided - they would pretend we couldn't find ours during their visit and gave us 30 days send them a "copy of our program" then approved the 25 pages I sent.
The biggest section of our (new) manual covers driving, as that's the most hazardous part of the job.