From the days of organochlorine insecticides such as aldrin, dieldrin, chlordane and heptachlor, alternative pest control chemicals of today are becoming more economical and effective in the protection of buildings and structures against termite attack, while at the same time leaving a smaller imprint on the environment.

Although the organochlorine insecticides have proven their efficacy in offering long-term protection and have been used as chemical barriers and also in direct applications to manage termite infestations, the government of Saudi Arabia has set out a policy which will see the eventual phasing out of such chemicals with better alternatives.
Subsequent to the policy, chemicals such as aldrin, dieldrin and heptachlor are no longer used to control termites in the kingdom, while the use of chlordane has been restricted for use in situations where effective alternatives are yet to be found.
For some years now, chlorpyrifos has been advocated for the prevention of termite attacks under suspended floors where retreatment is possible and also for use as a perimeter spray.
In 1994 chlorpyrifos was approved for treatment under concrete slab-on-ground construction. This was initially via a reticulation system installed prior to the laying of the concrete to allow retreatment. In 1995 the direct hand spraying of chlorpyrifos for treatment under concrete slab-on-ground was approved. They are concerns over the length of protection which may be achieved using chlorpyrifos on alkaline soils, due to concern that alkaline hydrolysis of chlorpyrifos would result in only a transient protection period.
In approving the use of chlorpyrifos there were significant concerns raised regarding the increased occupational health risks of using more acutely toxic chemical by hand spray and at times in confined spaces.
Another chemical that has been recently approved for the treatment of termites is Bifenthrin, a synthetic pyrethroid. Currently it is only approved for pre-construction treatment by hand spray.
Several other chemicals have been subjected to trials in the kingdom these include isofenphos, prothiophos, as well as alpha-cypermethrin and esfenvalerate. Pyrethroid and organophosphates have also been subjected to trials, but they have not been approved for commercial deployment for reasons that range from a lack of efficacy under climatic conditions to a lack of commercial viability.
In general using other chemicals such as permethrin depend on discovering the nest and treating it directly, however, several termite species which are successful in the urban environment are not necessarily nest builders.
Replacements of cyclodiene termiticides (some of the so-called ‘organochlorine’) with alternative chemical barriers has not been without occupational and public health risks. The toxicity of alternatives including the organophosphates (OPs), bifenthrin and hexaflumuron are briefly outlined below. On the basis of the high acute toxicity of the OPs and the fact that required treatments of houses by pest-control operators (PCOs) need to be much more frequent than with the cyclodiene formerly used, suggest that there is a greater risk of poisoning events, involving both PCOs and possibly householders and/or their pets.
The use of new technologies which include monitoring and baiting system to chemically kill termite colonies promises to dramatically reduce the potential exposure of PCOs and householders to termiticides.
Chlorpyrifos has been available in the kingdom since a long time and is registered for use as a termiticide. It is a toxic member of the OP class of chemicals (oral LD50 in rats reported to be in the range 96 to 300 mg/kg body weight), capable of acute cholinergic poisoning typical of the cholinesterase inhibitors. In Saudi Arabia ‘Dursban’, a chlorpyrifos combination from Dow, can only be used by trained licensed pest control operators.
Chlorpyrifos is relatively non-volatile (comparable to heptachlor and chlordane) but is reported to mild mercaptan odour which can be noticeable after treatment of dwellings.
Apart from their potential to cause acute poisoning because of their inhibition of cholinesterase, concerns about OP class of pesticides, including chlorpyrifos, relate to their potential for chronic effects (i.e. effects after repeated exposure), even if one-off exposures are small. These include their possible visual toxicity, neurobehavioral toxicity and delayed peripheral neuropathic effects.
In addition, organochlorine termiticides have long been recognised as a cause for environmental concern because of their persistent properties and tendency to bio-accumulate in wild life. These concerns led to the phase-out of their remaining termiticide uses. Impacts on wild life, environment and public health from the use of persistent organochlorines have been evident in recent years. Now Government authorities and organisations are going to ban these chemicals for the use of termite proofing.
Masa is using Josh 30.5 per cent SC, with the active ingredient imidacloprid, which belongs to the new chemical class chloronicotinyls, manufactured by Krishi Rasayan exports of India. It is a systemic and contact insecticide for the control of termites in buildings and is used both for pre- and post-construction treatments.
Josh is odourless and has relatively low toxicity towards people and pets, as it has contact and systemic action and impairs the physiological activity of termites. Termites stops feeding and get killed within few days. It spreads in all the directions by a process called lateral soil movements (LSM), ensuring thorough soil coverage.
The imidacloprid active ingredient is considered by the World Health Organisation (WHO) to be moderately toxic. In laboratory animals, symptoms of acute (short term) oral exposure to imidacloprid included apathy and laboured breathing which lasted for five days. The LD50 for imidacloprid (an oral dose that results in mortality to half of the test organisms) is 450 mg/kg body weight in rats and 131mg/kg in mice. The 24-hour dermal LD50 in rats is > 5,000 mg/kg.
It is considered non-irritating to eyes and skin from tests on rabbits.
Imidacloprid has been registered in about 120 countries and is also marketed for use over agricultural crops.
Masa is the sole distributor of Josh in the kingdom for more than six years, which has become the preferred termiticide by leading construction companies and consultants for its user and environmentally friendly qualities.
The termiticide, which is non-repellent and remains undetected by subterranean termites, has long residual life when applied as a barrier treatment. Being a water-based and odourless formulation, it is applicator and end-user friendly and is safer than conventional organophosphates. There are also fewer call backs, resulting in satisfied homeowners.
Imidacloprid is an insecticide with soil, seed and foliar uses for the control of sucking insects including rice hoppers, aphids, thrips, whiteflies, turf insects, soil insects and some beetles. Imidacloprid is most commonly used on rice, cereal, maize, potatoes, vegetables, sugar beets, fruits, cotton, hops and turfs, and is especially systemic when used as a seed or soil treatment.
Specifically it causes a blockage in a type of neuronal pathway (nicotinergic) that is more abundant in insects than in warm-blooded animals (making the chemical selectively more toxic to insects than warm blooded animals). This block leads to the accumulation of acetylcholine, an important neurotransmitter, resulting in the insect’s paralysis, and eventually death.