Paraquat has been grouped as Moderately hazardous by the World Health Organization (WHO)'s classification of pesticides by hazardous. This status has been interpreted as not cause much of a hazard and used as supportive evidence by pesticide manufacturers to oppose the ban on paraquat in many countries including Thailand where the decision on banning Paraquat is under process.
However, under this classification, there is a footnote specifically for Paraquat which rarely mentioned.
In an exclusive interview with Thai PBS on March 2, Carolyn Vickers, WHO's Team Leader on Chemical Safety, recommended that protecting public health should be the key factor when considering whether Paraquat should be banned.
In the case of Paraquat, there is special footnote which said that it has serious delay effect if absorb and it relatively low hazard in normal use but may be fatal if the concentrated product is taken by mouth or spread on the skin, Ms Vickers said
In the WHO's Basic Analytical Toxicology, Paraquat dichloride has been marked as an extremely poisonous. Consuming 4 milligrammes of paraquat per one kilogramm of body weight can be life threatening. Ingestion of Paraquat can lead to severe acute pesticide poisoning, including fatal ones.
Despite a claim by Paraquat manufacturer that Paraquat is a safe when used as directed on the label, many countries decided to put the use of this chemical substance under control.
Countries that regulated the use of Paraquat, including the United States, Australia and New Zealand, have imposed very strict guidelines on the use of the pesticide.
However, WHO has expressed concerns over lacking of rigorous legislation and regulations to control pesticides in developing countries.
Ms Vickers stated that in developing country, risk reduction measure, personal protective equipment, and calibration of pesticide may not be easily implemented and not effective. Therefore, the local regulatory authority need to keep careful watch on what happening in the country.
If the existing measures were not enough to protect the public health, then more needs to be done to safeguard farm workers and consumers, she said.
The latest International Code of Conduct on Pesticide Management provided by the WHO and the Food and Agriculture Organization of the United Nations (FAO) stated that if personal protective equipment is required and those equipment is uncomfortable, expensive or not readily available, the use of particular pesticides should be avoided especially in the case of small-scale users and farm workers in hot climates.
WHO chemical safety expert noted that this code of conduct covers all pesticides and the practice depends on the final formulation of the pesticide.
Regarding alternatives to Paraquat, Ms Vickers advised that experiences from countries that have banned Paraquat showed that there were always safer measures to deal with pests and herbs.
It is just that each country need to consider the issue themselves and make a decision, she said.Reporting by Chalarntorn Yothasmutra
Source: Thai Public Broadcasting Service (ThaiPBS)