OSHA standards for circular saws apply to blades with diameters greater than 2 inches.
Portable circular saws are required to have upper and lower guards. The upper guard must cover the saw blade. The lower guard must cover the saw blade and be retractable—that is, it must automatically cover the blade when the tool is not in use.
Handheld circular saws are required to have a constant-pressure control that will stop electric power when the pressure stops.
Circular saws either crosscut or rip the wood grain, depending on the blade. OSHA suggests that users be particularly careful about using the proper type of blade.
OSHA suggests that the saw blade be directed away from anyone in the area. In addition, OSHA suggests face and eye protection.