The terms guard and shield are often used interchangeably when referring to safeguarding cutting and turning machines. However, there is a significant difference between the two words.
Guards
OSHA 29 CFR 1910.217 defines a guard as an enclosure that prevents anyone from reaching over, under, around, or through the guard even if they really tried. Guards are often used when a machine risk assessment shows a high level of exposure to recognized hazards.
ANSI B11 safety standards require that guard access doors be electrically interlocked using switches designed to be difficult to defeat. This is particularly important for doors that are frequently accessed.
Shields
Shields, on the other hand, are designed for lower levels of exposures (to hazards). Most shields are designed to knock down chips and coolant in cutting/turning operations, while still providing visibility into the point of operation.
When the question arises as to which to apply, remember that guards must always provide a higher level of protection than shields.
Rockford Systems encourages all employees to exceed the minimum requirements and abide by best safety practices at all times.