Posted By Doug Russell
Jay

No easy answer to the question. It depends a lot on the temperatures involved, quality of PPE and nature of the work. It is possible for a worker to suffer heat stress if they are doing physically demanding work while wearing protective clothing in temperatures below freezing. For work in chillers around zero Celsius, good PPE and normal breaks are probably sufficient. Once you get down to blast freezers at minus 30 Celsius no amount of PPE will ever be sufficient and some breaks at ambient temperatures will be needed.

There is a useful British Standard - BS 7915:1998 on 'the ergonomics of the thermal environment - guide to design and evaluation of working practices for cold indoor working environments'. And a German DIN standard DIN Standard 33403-5 'Climate at workplaces and their environments. Ergonomic design of cold workplaces' January 1997 covers the same ground. The DIN standard has a useful table that suggests for moderate work with good PPE there should be a 30 minute break after 90 minutes work at minus 18 to minus 30 Celsius and a 60 minute break after 60 minutes work at minus 30 and below.

Health issues to consider include asthma or other respiratory conditions (freezer air is very dry), cardiovascular and circulatory conditions such as Raynaud's disease.

You may also need to consider lone-working and trapped-person alarms/means of escape if there is an accidental lock-in.

And don't forget the basic duty under reg 7 of the Wokplace regs is to keep individual workers exposure to the low temperatures to a minimum.

Posted By Catman
Hi Jay

You may already have this under control but I have found that the noise level in some blast freezers also necessitates frequent staff rotation.

Cheers
TW