Occupational Safety & Health Administration has published a few brochures of particular interest to Machine Guarding and general safety practices:
OSHA 3170 - Safeguarding Equipment and Protecting Employees from Amputations
60 pages, 2007
https://www.osha.gov/Publications/osha3170.pdf
OSHA 3885 - Recommended Practices for Safety and Health Programs
40 pages, 2016
https://www.osha.gov/shpguidelines/docs/OSHA_SHP_Recommended_Practices.pdf
OSHA 3302 - All About OSHA
36 pages, 2020 (Update)
https://www.osha.gov/Publications/all_about_OSHA.pdf
OSHA 2209 - Small Business Handbook
86 pages, (Updated) 2022
Machinery & Machine Guarding: pages 41-45
https://www.osha.gov/sites/default/files/publications/small-business.pdf
OSHA 3000 - Employer Rights and Responsibilities Following a Federal OSHA Inspection
28 pages, 2018 (update)
https://www.osha.gov/Publications/osha3000.pdf
OSHA 2254 - Training Requirements in OSHA Standards
270 pages, 2015
Subpart O - Machinery & Machine Guarding: Page 65
https://www.osha.gov/sites/default/files/publications/osha2254.pdf
Canadian Safety Publications
Various Canadian safety agencies have also published machine safety guidelines:
Guideline for Safeguarding Machinery and Equipment
(BC) 107 pages, 2008
Download the PDF
Guidelines for Pre-Start Health and Safety Reviews
(ON) 42 pages, 2001
Download the PDF
Guide RG-597: Fixed guards and safety distances
(QC) 71 pages, 2009
Download the PDF