We are occasionally asked “what is a safe temperature for contact with hot items in the workplace?”
The Regulations are silent on this topic and the codes of practice offer little specific advice. However, various research papers and ergonomic publications offer practical guidance on recommended temperatures for various situations.
Most people with workplace enquiries are interested in surface temperatures where inadvertent touching could cause a burn injury, such as hot steam pipes. However, other workplaces (such as health care) are more concerned about safe water temperature e.g. washing hands or showers.
Below we outline the issues and suggested controls for these two situations.
Touching hot surfaces
In offering advice on safe surface temperature for touch, the two key parameters include what the material is made of and duration of contact to cause a specified level of burn.
Below is a summarised table assuming contact with fingers or palm of hand (not sensitive skin areas) and for temperatures which could cause indicated burns for the indicated contact duration.
1st Degree Burn (minor burn):
- Non-metallic 85°C brief contact
- Metal 60°C brief contact
- Metal 50°C hold
2nd Degree Burn (damage to underlying tissue):
- Metal 100°C for 15 seconds contact
- 82°C for 30 seconds contact
- 71°C for 60 seconds contact
Immersion in hot water
Safe temperature for water has two concerns:
- Too hot causing burns; and
- Not hot enough causing growth of Legionella bacteria over time.
How do we check the surface temperature?
For water it is easy, you use a traditional thermometer to confirm outlets are within a safe range. For metals and other solids you can use an infrared thermometer.
Tip: For shiny surfaces such as stainless steel piping, place a piece of black masking tape on the surface.
Wait a couple of minutes for the tape to equalise its temperature with the metal underneath, and then check the temperature.
What if it’s too hot?
Preferably, we need to control the temperature at the source of the hot item e.g. water supply, but where this is not possible controls such as shielding hot pipes & placing warning signage, or using adjustable or mixer controls on water outlet taps is appropriate.