Certified organic food contains less pesticide residue than other foods. This is the safest choice if you want to reduce the amount of pesticide you are consuming.
Because some pesticides remain in the soil and water for many years, these chemicals end up in crops that were not sprayed by the farmer. This means that even organic food may contain some residues. This happens in all parts of the world, not just Thailand, but scientists believe that the difference between organic and non-organic food will make a difference to your health.
Food that is labelled “safe” or “hygienic” probably contains more pesticide residues than organic food, but less than non-labelled. In the future these may become relatively safe choices if organic food is not available.
"Tests carried out by the Department of Agriculture showed that 18% of kale and morning glory that was labelled as “safe” contained pesticides residues above the Maximum Residue Level (MRL). In the case of unlabelled samples, there was 29% above the MRL. These tests suggest that labelled foods are slightly safer. But other tests, carried out by the Ministry of Public Health, did not find a significant difference between residues in labelled and unlabelled vegetables. The conclusion is that Thai consumers could not trust these labels in the past. These consumers are now hoping that producers, wholesalers and the Government will make more effort in the future to enforce the standards that are being promoted."
To accurately test residues in food, expensive laboratories and trained laboratory staff are needed. Gas chromatographs and other sensitive equipment are needed. This method of residue testing is slow and expensive, but it gives very accurate and useful results. For each sample the test can say exactly which pesticides were present, and it can also tell how much residue was found. This makes it possible to compare the sample with the Maximum Residue Levels.
The Department of Agriculture has a several laboratories in Bangkok and in the regions, that use this method. these laboratories test samples of farmers who want export and also of farmers who want to be certified with the new “food safety” logo.
While the simple GT-test kit can only give a rough indication about residues belonging to the organophosphates and carbamates, this multi-residue method can detect all known pesticides.