P U B L I C A T I O N S CODON Quality Assurance and Safety of Crops & Foods, 2021; 13(3): 45–52 ISSN 1757-837X online, DOI 10.15586/qas.v13i3.913 45 P U B L I C A T I O N S CODON The ef fciency of various household processing for removing chlorpyrifos and cypermethrin in Chinese kale and Pakchoi Phannika Tongjai 1 , Surat Hongsibsong 2, *, Ratana Sapbamrer 3 1 Faculty of Public Health, Chiang Mai University, 50200, Tailand; 2 School of Health Sciences Research, Research Institute for Health Sciences, Chiang Mai University, Tailand; 3 Department of Community Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Tailand *Corresponding author: Surat Hongsibsong, School of Health Science Research, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai, 50200, Tailand. Email: surat.hongsibsong@cmu.ac.th Received: 21 April 2021; Accepted: 1 August 2021; Published: 25 August 2021 © 2021 Codon Publications OPEN ACCESS RESEARCH ARTICLE Abstract Te vegetables, Chinese kale and Pakchoi, which are popular among the Tai people, are found to have problems with residues of pesticide. Te pesticide residues in both Kale and Pakchoi were chlorpyrifos and cypermethrin. Tis research was to study the efciency of pesticide residue reduction in Chinese kale and Pakchoi samples by using various household wash processing. Te process included washing with normal water, 0.10% NaCl, baking soda, water fowing, and blanching. Pesticide residues were extracted from Chinese kale and Pakchoi to determine the amount of chlorpyriphos and cypermethrin residue by using analytical tools such as Gas Chromatography— Flame Photometric Detector (FPD) and Gas Chromatography—Electron Capture Detector (ECD). Te results showed that the household processes for reducing the chlorpyrifos residue in Chinese kale and Pakchoi were the following: residues were reduced by 52.70–65.41%, 58.33–62.14%, 59.46–80.52%, and 46.04–62.85% when washed with normal water, 0.10 % NaCl, baking soda, and water fowing through, respectively. Similarly, the household processes for reducing cypermethrin residue in Chinese kale and Pakchoi were the following: residues were reduced by 51.13–66.29%, 33.75–45.65%, 38.14–63.64%, and 44.88–61.63% when washed with normal water, 10% NaCl, baking soda, and water fowing through, respectively. Also, blanching reduced the chlorpyrifos residue by 37.96–50.44% and the cypermethrin residue by 47.86–52.42%. Terefore, while washing vegetables by soaking and dissolving substances, baking soda is the most efective when used for washing for at least 15 min to reduce the residue of pesticides. Te consumers should be provided vegetables that are cleaned and have had a proper washing for removing pesticide residues and toxic residues. Keywords: Chlorpyrifos; Cypermethrin; Residue Reduction; Household Washing Introduction In Tailand, vegetables are considered as major constit- uents of diet, and it is recommended that 400 g of vege- tables should be consumed per day. Although vegetables have many health benefts, toxic residue is a problem in the fruit and vegetable consumption chain. Several fac- tors, mainly diseases, pests, and insects, are responsible for the loss of productivity of crops. Terefore, chemicals have been used to address these problems. Chinese kale and Pakchoi are the most popular vegetables, as they pro- vide a better return on investment for farmers. To improve their yield and quality, insects and pests are controlled or eliminated. Tis results in farmers using pesticides beyond the recommended level, leading to high chem- ical residue in vegetables. Residues exceeding the maxi- mum residue limits (MRL) were detected in vegetables in the farms, local markets, and the supermarket in Phayao Province in northern Tailand. Te most commonly used OP (Organophosphate) pesticides are chlorpyrifos,