Developing powder paints with insect repellent activity

Indeed, in certain populated areas mosquitos are carriers of fatal diseases such as malaria and encephalitis, in addition to being responsible for the ailing health of millions of people, children being the most vulnerable group of the population.

Unstable when subjected to heat

A large number of repellent substances exist, however, despite the usefulness of the same, one of their greatest limitations is that they are thermolabile substances, or in other words, unstable when subjected to heat. This characteristic hampers the use of the same in many areas, such as the powder paint sector, due to the fact these substances are incompatible with the manufacturing and/or application processes used, as they are subject to degradation and volatization.

Research project has been concluded

Adapta, with the financial backing of the Centro para el Desarrollo Tecnológico (Industrial Technology Development Center), has concluded a research project geared to obtaining insect repellent powder paint by means of processes involving the production and application designed especially to preserve the activity of these repellent substances. The characterisation of materials by means of thermogravimetry, infrared spectroscopy and the chromatographic analysis of the end products resulted in the confirmation of the existence of a high percentage of repellent substance. In turn, a procedure has been developed for the selective extraction of the insecticides which allows for the optimisation of the chromatographic analysis method.

Efficient against carrier of yellow fever

The powder paint obtained has been tested by a prestigious specialist laboratory, and registered an efficacy of 62% against the Adedes aegypti mosquito. This mosquito is the carrier of the yellow fever and dengue fever viruses. Testing was conducted in accordance with the methodologies used by the international agencies WHO Guidelines for Efficacy Testing of Spatial Repellents and Technical Notes for Guidance by the European Commission. Based on the results obtained and the information contained in scientific literature, the paint features repellent activity. This activity could be improved by increasing the active substance percentage to the maximum concentration limits published by the US Department of Defence in Insect Repellents: Principles, Methods and Uses.

Practical use on garden furniture

The repellent effect on the materials could last for up to two years. In the case of the powder paint it has been proved that the kinetic release model followed by coating is first order, reason for which a repellent activity of greater than two years is foreseeable. The efficacy of the coating and the duration of the same on end products should be analysed on an individual basis in the environmental conditions which are closest to those of the final use of the product. One of the possible practical uses of this paint is on garden furniture, reason for which it has been developed with outdoor qualities and in a shiny white colour. Initially, the product features no limitations with regard to production in other qualities, colours or finishes. The coating does not release any odours and contains no active substances which may be toxic to humans, and no systemic health effects have been reported. It has been proved that the paint undergoes no significant loss of the active substance when subjected to normal cleaning operations.