Labor & Industries (L&I), Washington State

Machine Safety Chapter 296-806, WAC

Effective Date: 01/01/05

WAC 296-806-200 Requirements for All Machines

For printing

Safeguarding Methods

Guards

WAC 296-806-20042

Make sure guards meet these requirements

You must

• Make sure guards do not create additional hazards such as sharp edges or pinch points between the guard and moving machine parts.
• Make sure guards are:
  • – Made of durable materials
  • – Strong enough to withstand the forces to which they are exposed
  • – Securely fastened to the machine, if possible, or to the building structure if they cannot be attached to the machine
• Make sure guards protect employees by doing both of the following:
  • – Preventing hands or other body parts from reaching through, over, under, or around the guard into the hazard area
    and
  • – Preventing objects or debris from falling onto or being thrown towards an employee.
• Make sure barrier guards:
  • – Are properly installed, adjusted, and maintained
  • – Have no opening at any point larger than shown in Table 200-1, Largest Allowable Guard Opening

  Reference: Metal cutting shears are allowed to be guarded with properly applied awareness barrier safeguarding as described in ANSI B11.4-1993, Sections 6.3.3.

This diagram illustrates the information found in Table 200-1. The size of the opening in the guard, or between the bottom edge of the guard and the feed table is small enough to prevent any part of the operator’s body from reaching the hazardous area.

Illustration 200-1
DISTANCE FROM HAZARD TO GUARD (A)

 

WAC 296-806-20044

Make sure devices meet these requirements

You must

• Make sure devices used to safeguard employees do either of the following:
  • – Stop the motion of a moving part before an employee comes in contact with it and has to be manually reset before machines can be restarted
    or
  • – Be designed and constructed to prevent the operator from having any part of their body in the danger zone during the hazardous part of the operating cycle.

  Reference: For more information on installation of safety devices, see Performance Criteria for Safeguarding, ANSI B11.19-2003.

WAC 296-806-20046

Make sure light curtains meet these requirements

IMPORTANT:

All devices must meet the general requirements for devices found in Make sure devices meet these requirements, WAC 296-806-20044.

You must

• Make sure light curtains, when used:
  • – Respond to the presence of an operator’s hand, other body part, or a work piece
  • – Have indicators that are easily seen by the operator showing when the device is functioning or has been bypassed.

  Note: Even if a shiny reflective object or work piece is used with a light curtain or other electro-optical device, it should still respond to the operator’s hand or other body part

You must

• Make sure only authorized persons can make the following adjustments to light curtains:
  • – Variations in operating conditions
  • – Fixed or channel blanking
  • – Floating blanking (sometimes referred to as floating channel or floating window features)
• Safeguard access to the point of operation that is not protected by light curtains.

Reference: For more information on light curtains and their requirements, see Performance Criteria for Safeguarding, ANSI B11.19-2003.

 

WAC 296-806-20048

Make sure pressure-sensitive mats meet these requirements

IMPORTANT:

All devices must meet the general requirements for devices found in Make sure devices meet these requirements, WAC 296-806-20044.

You must

• Make sure pressure-sensitive mats:
  • – Detect the presence or absence of the operator or others
  • – Send the stop command and prevent successive machine cycles if any single component fails
  • – Are connected with the machine control system so the device’s stop signal immediately stops action of the machine tool and requires use of the start control before the machine can begin another cycle
  • – Are located so that the operator can not reach the recognized hazard before hazardous motion has stopped
  • – Have an indicator easily seen by the operator that shows the mat is operating.

WAC 296-806-20050

Make sure restraint or pullback devices meet these requirements

IMPORTANT:

All devices must meet the general requirements for devices found in Make sure devices meet these requirements, WAC 296-806-20044.

You must

• Make sure restraint or pullback devices:
  • – Prevent the operator from reaching into the point of operation or withdraw the operator’s hands from the point of operation before motion of the machine creates a hazard
  • – Have fasteners, pins, and other items used to secure and maintain the setting of the device applied in a way that minimizes loosening, slipping, or failure during use
  • – Are worn inside gloves, if used, so if a glove becomes trapped inside a machine or tool, the device can still remove the operator’s hand from the hazard area.

WAC 296-806-20052

Make sure two-hand devices meet these requirements

IMPORTANT:

All devices must meet the general requirements for devices found in Make sure devices meet these requirements, WAC 296-806-20044.

You must

• Make sure two-hand devices:
  • – Protect each hand device against accidental operation
  • – Require simultaneous operation of both hand devices to begin the cycle, including the first cycle (automatic mode)
  • – Are provided with an anti-repeat feature when used in single cycle mode
  • – Have a set of devices for each operator if more than one needs to be safeguarded
  • – Are located far enough from the nearest hazard so the operator can not reach the hazard before hazardous motion stops.

    Reference: For more information on proper installation of safety devices, see Performance Criteria for Safeguarding, ANSI B11.19-2003.

WAC 296-806-20054

Make sure devices used with barrier guards meet these requirements

IMPORTANT:

All devices must meet the general requirements for devices found in Make sure devices meet these requirements, WAC 296-806-20044.

You must

• Make sure movable barrier devices:
  • – Return to the open position if they encounter an obstruction while enclosing the hazardous area
  • – Are designed so the operator or others cannot reach the hazard by reaching over, under, around or through the device when it is in the closed position.
• Make sure interlocks used with barrier guards do all of the following:
  • – Stop hazardous motion of machines when interlocks are open
  • – Are not easily bypassed
  • – Are designed and installed so that closing the interlocks won't cause a hazard to employees.

WAC 296-806-20056

Make sure safeguarding by distance meets these requirements

You must

• Make sure means used to safeguard by distance do both of the following:
  • – Prevent parts or material from falling on employees below
    and
  • – Separate employees on fixed ladders, stairs, floors, or other walking or working surfaces from the hazard by:
    • More than 7 feet vertically
      or
    • A horizontal distance that prevents employees from contacting or being injured by the hazard according to the distances in Table 200-2.

Table 200-2 helps you identify either the required horizontal distance from the hazard to the barricade (B), or the required height of the barricade (C), as long as you know A and either variable, B or C.

Table 200-2

Safe Distances for Fixed Barricades (B)

Height of the Barricade (C)

	96	86	78	71	63	55	48	40
96	0	4	4	4	4	4	4	4
86		10	14	16	20	20	24	24
78			14	20	24	28	36	43
71				24	36	36	40	43
63				20	36	36	40	51
55				4	32	36	40	55
48					20	36	40	55
40					12	36	40	55
32						24	36	51
24							20	48
16							12	48
8							8	43

Note: The height and distance requirements of Table 200-2 are designed to safeguard workers from a fixed hazard. If a hazard involves flying chips, fluids, parts or materials, the barrier height, distance, and construction may need to be adjusted to provide adequate protection.

 

Illustration 200-2
HOW TO MEASURE VARIABLES FOR TABLE 200-2

 

Examples:

• If the height of the hazard (A) is 78 inches, and the horizontal distance from the hazard to the barricade (B) is 14 inches, the required height of the barricade (C) is 78 inches.
• If the height of the hazard (A) is 86 inches, and the height of the barricade (C) is 55 inches, then the required horizontal distance from the hazard to the barricade (B) is 20 inches.

WAC 296-806-20058

Make sure guardrails used for safeguarding meet these requirements

Note: Guardrails may be used to safeguard: – Flywheels – Cranks and connecting rods – Tail rods and extension piston rods – Horizontal belts in a power generating room – Clutches, cutoff couplings, or clutch pulleys in an engine room occupied only by an attendant – Power transmission parts on a runway used only for oiling, maintenance, running adjustment, or repair work.

You must

• Make sure top rails are:
  • – Smooth-surfaced
  • – Strong enough to withstand a force of at least 200 pounds
  • – Between 39 and 45 inches above the floor, platform, runway, or ramp
• Make sure guardrails have an intermediate rail (midrail) installed approximately halfway between the top rail and the floor, platform, runway, or ramp
• Make sure rails don't extend beyond the end posts of the guardrail and create a projection hazard
• Make sure toe boards, if required by this chapter to safeguard a machinery hazard, are:
  • – At least 4 inches high
  • – Securely fastened in place with no more than ¼ inch between the bottom of the toe board and the floor, platform, runway, or ramp
  • – Made of substantial material that's either solid or that has openings in the material no larger than one inch.