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 as part of a commercial pest control treatment 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.

Check services staff work on a commercial pest control heat treatment

1. The machinery is completely wrapped and hot air is blown in from heaters positioned outside.

Commercial pest control heat treatment measuring temperature

2. Check staff monitor the temperature.

As well as recording temperatures with probes placed inside the machinery, manual readings are regularly taken to ensure that there are now ‘cold spots’. These are areas where insects may potentially survive leading to the risk of treatment failure. (See picture 2)

Where cold spots are found, the heating system is adjusted to ensure a high temperature throughout. (See picture 3)

Check services staff adjust heaters on commercial pest control heat treatment

3. Airflow is adjusted within the bubble to eliminate any cold spots.

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 are increased above 52°C for more than an hour.

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.

Heat treatment graph of temperatures against time

4. Temperature probes fitted inside the bubble record temperature over time.