5. Heat Treatment

The use of heat to eradicate insect pests is not a new concept but has only recently become a viable system for the control of Stored Product Insects (SPIs) in production equipment. Using heat has many benefits including:

• It is a permitted form of control for sites complying with Soil Association Organic Standard.
• There is no need for a factory shutdown and production can carry on around the area being heat treated. Limited downtime will clearly lead to significant cost savings.
• Treatment does not use chemicals so does not leave residues that can cause contamination.
• Heat can penetrate airtight systems and therefore can kill insects where fumigations fail.
• Treatment can be localised, focusing on a piece of production equipment known to be infested.
• It is possible to walk inside the ‘bubble’ to alter the focus of the treatment and also to view the treatment progressing.

The Proccess
The equipment to be treated is covered to keep the heat within the treatment area and hot air is pumped into the system (See Photo 1 below).The equipment temperature is recorded accurately at various points using temperature sensors. These are then recorded via software onto a laptop that can display the information in various formats such as a graph (See Photo 2 below).

Photo 1 : Hot air being pumped into bubble.

Photo 2 : Temperature and humidity readings Vs Time

All insects will die when temperatures are increased sufficiently and although the lethal temperature does vary a little between species, almost all die when temperatures rise above 52°C.

Once the treatment is completed the equipment can be switched off and the bubble removed. Unless there is temperature sensitive product involved the equipment can be restarted quickly after the covers are removed.

A full report is then sent to the customer providing graphs, tables and an interpretation of all of the results.