Refer to Work Rate Assessment – RESP-FIT RPD Online for more information on the background of Work Rates and Respiratory Protective Devices (RPD) as part of AS/NZS ISO RPD Standards.

The expected work rate should be determined in order to select RPD with the appropriate work rate class. Four work rate classes, W1, W2, W3 and W4, are designated for RPD; however, those with standardized connector according to AS/NZS ISO 17420-3 are limited up to work rate W2.

To determine the required work rate class, the highest class according to the descriptions below should be used.

NOTE: Further information on work rates and work activities is given in SA/SNZ TS ISO 16976.1:2024.

Work rate class Work Examples of work and activities
W1 Light to moderate Average for full work shifts including breaks

Sitting at ease: light manual work (writing, typing, drawing, sewing, bookkeeping); hand and arm work (small bench tools, inspection, assembly or sorting of light materials); arm and leg work [driving vehicle in normal conditions, operating foot switch or pedal, standing drilling (small parts), milling machine (small parts), coil winding, small armature winding, machining with low power tools]

To:

Sustained hand and arm work (hammering in nails, filing); arm and leg work (off-road operation of lorries, tractors or construction equipment); arm and trunk work (work with pneumatic hammer, tractor assembly, plastering, intermittent handling of moderately heavy material, weeding, hoeing, picking fruits or vegetables, pushing or pulling light-weight carts or wheelbarrows, forging); walking at a speed of up to 5,5 km/h
W2 Heavy to Very Heavy Average for full work shifts including breaks

Intense arm and trunk work (carrying heavy material, shovelling, sledgehammer work, sawing, planing or chiselling hard wood, hand mowing, digging, pushing or pulling heavily loaded hand carts or wheelbarrows, chipping castings, concrete block laying)

To:

Very intense activity at fast pace; working with an axe; intense shovelling or digging; climbing stairs, ramp or ladder; walking quickly with small forms; running; walking at a speed greater than 5,5 km/h
W3 Very, very heavy to extremely heavy Continuous work for up to 2 h without breaks

Safety and rescue work with heavy equipment and/or personal protective equipment; fit individuals pacing themselves at 50 % to 60 % of their maximal aerobic capacity; walking quickly or running with protective equipment and/or tools and goods; walking at 5 km/h and 10 % elevation

To:

Continuous work for up to 15 min without breaks.

Rescue and fire-fighting work at high intensity; fit and well-trained individuals pacing themselves at 70 % to 80 % of their maximal aerobic capacity; searching contaminated spaces; crawling under and climbing over obstacles; removing debris; carrying a hose; walking at 5 km/h and 15 % elevation
W4 Maximal Continuous work for less than 5 min without breaks

Rescue and firefighting work at maximal intensity; fit and well-trained individuals pacing themselves at 80 % to 90 % of their maximal physical work capacity; climbing stairs and ladders at high speed; removing and carrying victims; walking at 5 km/h and 20 % elevation

Reference/s for further information and detail:

  • SA/SNZ TS ISO 16975.1:2023 – Selection, use and maintenance – Section 7.3.3.4
  • AS/NZS ISO 16976.1:2024 – Human Factors – Metabolic rates and respiratory flow rates