Electrical cables are installed in almost all types of environments, and some are in areas more conducive for exposure to pests, rodents or termites. This is especially so for cables that are buried direct or for underground use cables.
Cable materials are attractive to rodents due to the presence of plasticizers and aromatic odours. The colour and texture of the cable sheath material are also attractive to them. Termites live in underground nests deep in the soil. While their basic diet is cellulose, such as organic wastes and roots of plants, once they have consumed natural sources of cellulose, they would look for other manmade sources such as cables.
When cables insulation layer is chewed through, this can cause short circuits and potentially start an electrical fire. Therefore, where there is risk of pests, rodents or termites, we would need to consider protective barriers or additives to be added to the cables to prevent damage.
How can we protect cables from rodents, pests and termites?
There are two general methods to protect cables from rodents, pests and termites, which are the use of physical barriers and chemical additives.
For rodent and pest issues, physical barriers that help to protect against them include the use of conduits and armouring tapes. These barriers are designed to prevent pests and rodents from gnawing on the cables. For fibre optic cables the use of fibre glass yarns is popular where it becomes broken when bitten into and is unpleasant for the rodent.
For termites, an effective long-term physical barrier would be Nylon-12, which is a tough material that termites are unable to bite through.
In general, these physical methods may last longer, but tend to be costly as well.
An effective alternative is the use of chemical additives labelled pest resistance (PR), anti-rodent (AR), and anti-termite (AT). Additives are added to the outer sheath of the cable when it is being extruded to provide long lasting effectiveness due to the controlled release of the active ingredients.
Example of anti-rodent ingredients include capsaicin (think chilli!), which are added and cause the sheath to have a spicy or bitter taste which discourages animals from gnawing on the cables. Since the olfactory sense of animals is superior to humans, the additives give off an unattractive scent to animals but is non-toxic and not detectable to humans.
Anti-termite cables on the other hand are treated with insect growth regulators which serves to repel and disrupt their growth and reproduction rather than to exterminate them.
If you know your cables are going to be installed in an environment where there could be potential pest attacks, do check in with your cable manufacturer on the physical or chemical additives that would be suitable for your needs.
At Keystone, when it comes to AR, PR, AT chemical additives, our approach has been to use 1) non-toxic products that are not harmful to humans or animals, and 2) environmentally safe products.