Industrial and manufacturing plants and assemblies are closely associated with machine guarding as an element for protection of workers and those around them.

Machine guarding is one of the essential elements that concerns industrial and manufacturing plants. Machines that fall into the category of guillotine cutters, shears, alligator shears, power presses, milling machines, power saws, jointers, forming rolls and calendars, and various portable power tools are just some of the basic machines that require guarding. 

In California Cal-OSHA machine guarding requirements are found under Subchapter 7. General Industry Safety Orders, Group 8. Points of Operation and Other Hazardous Parts of Machinery 

Article 54. Scope and General Definitions, Section 4184 which states the following:

(a) Machines as specifically covered hereafter in Group 8, having a grinding, shearing, punching, pressing, squeezing, drawing, cutting, rolling, mixing or similar action, in which an employee comes within the danger zone shall be guarded at the point of operation in one or a combination of the ways specified in the following orders, or by other means or methods which will provide equivalent protection for the employee.

(b) All machines or parts of machines, used in any industry or type of work not specifically covered in Group 8, which present similar hazards as the machines covered under these point of operation orders, shall be guarded at their point of operation as required by the regulations contained in Group 8.

Exception: Microtomes (also called histotomes or cryostats) when guarding as required in Section 4184 is infeasible and the microtome is used, operated and maintained in accordance with Section 3558 of these Orders. For the purposes of this Exception guarding as required in Section 4184 is infeasible under circumstances that include, but are not limited to the following: there is no point-of-operation guard commercially available for an employer’s microtome.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

Similar language is found in the United States Department of Labor Occupational Safety & Health Administration guidelines for machine guarding Section 1910.212(a)(1):

Types of guarding. One or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, ingoing nip points, rotating parts, flying chips and sparks. Examples of guarding methods are-barrier guards, two-hand tripping devices, electronic safety devices, etc.

It is important to note that machine guarding alone is not sufficient when maintaining any equipment.  Proper Lockout, Tag-out, or Block-out protocol must be followed.  A July 2019 publication by Cal-OSHA noted the following:

Failure to lockout, tag-out, and block-out (LOTO) machinery before working on it is a major cause of serious injuries and deaths. Workers can be electrocuted, suffer severe crushing injuries, and lose fingers, hands, and arms because machinery is inadvertently turned on while it is being cleaned, repaired, serviced, set-up, adjusted, or unjammed.

(For more information see Cal-OSHA Subchapter 7. General Industry Safety Orders, Group 2. Safe Practices and Personal Protection, Article 7. Miscellaneous Safe Practices Lockout / Tag-out / Block-out, Section 3314)

The author started to work with heavy machinery dating back to the early 1970’s.  The nearly 50 years of hands on experience, numerous installations, and scores of investigations, in addition to certifications and licenses, has provided the type of experience that allows the author to provide expert opinions regarding machine guarding and other industrial safety topic.