Pesticides are applied to crops to save them from pest and diseases by repeated application for effective control. The formulation of a pesticide has to meet the demands of efficacy and suitability to the mode of application and minimize the damage to the environment. But conventional pesticides are often blamed to damage the environment.

It was estimated that about 2.5 million tons of conventional pesticides are used on crops each year and it is expected that this can cause worldwide damage due to high toxicity and non-biodegradability of pesticides and lack of scientific formulations, leaching and loss during application going into soil, water bodies and atmosphere causing pollution or remained on the crop surfaces affecting ecology and public health.

But nano encapsulated pesticides are claimed to meet these demands in that they enable smaller quantities of the pesticides to be used effectively without much damage to the environment. Several approaches have been undertaken to develop nano pesticide formulations, but research on the molecular mechanism of action of nano pesticides in insects, biosafety and molecular interaction with plant, soil and environment is very limited. When the nano formulations are applied as foliar spray or in the soil, the carrier and pesticide interact with the soil, insect, plant and atmosphere. It is not clearly known how these nano encapsulated pesticides are degraded in the soil. It is expected that large number of nano formulations will be introduced commercially. The environmental problems caused by overuse of the aforesaid pesticides have attracted a lot of attention of scientists in recent years engaged in basic research.
Issues

Nano encapsulated pesticides have benefits and prospects, but have to address many important issues while designing the nano carriers. Cost of the material and processing of the nano encapsulated formulations should be low, nano carriers should not damage the environment, plant and soil, nano carrier additives like fillers, stabilizers, antioxidants should be safe to the environment when handling and disposal. They should not have environmental impact due to degradation of the carriers and additives in response to heat, hydrolysis, oxidation, solar radiation and biological agents, and be approved by regulatory agencies.

More generally, it sends a message to any company using nanotechnology that they need to be vigilant in how they portray their products, both in terms of possible risks and benefits.