Thailand updates the environmental standard for soil 
The National Environmental Board of Thailand announced “Notification of the National Environmental Board: Soil Quality Standard” in the Royal Gazette on 11 March 2021. The notification issued under the Enhancement and Conservation of National Environmental Quality Act B.E.2535 (1992) repeals and replaces “Notification of the National Environmental Board, No. 25, B.E. 2547 (2004) Soil quality standard”.
The standard categorizes soil into two groups based on land use namely, (1) residential use and (2) other use such as agriculture or industry. Several new parameters, copper, chlorpyrifos, glyphosate, paraquat dichloride, and 2,3,7,8-TCDD, were added. Moreover, PCBs in the old standard were replaced by PCB-126. Standard value was also updated based on a risk-based approach.
Soil Standard for Other Use
| Parameter | Old standard | New standard | |
| 1. Volatile Organic Compound | Unit (mg/kg) | Unit (mg/kg) | |
| 1 | Benzene | 15 | 5 |
| 2 | Carbon Tetrachloride | 5.3 | 30 |
| 3 | 1,2-Dichloroethane | 7.6 | 21 |
| 4 | 1,1-Dichloroethylene | 1.2 | 993 |
| 5 | cis-1,2-Dichloroethylene | 150 | 1750 |
| 6 | trans-1,2-Dichloroethylene | 210 | 17500 |
| 7 | Dichloromethane | 210 | 2750 |
| 8 | Ethylbenzene | 230 | 19350 |
| 9 | Styrene | 1700 | 33190 |
| 10 | Tetrachloroethylene | 190 | 382 |
| 11 | Toluene | 520 | 40140 |
| 12 | Trichloroethylene | 61 | 6 |
| 13 | 1,1,1-Trichloroethane | 1400 | 35400 |
| 14 | 1,1,2-Trichloroethane | 19 | 6 |
| 15 | Total Xylenes | 210 | 2478 |
| 2. Heavy Metals | Unit (mg/kg) | Unit (mg/kg) | |
| 1 | Arsenic | 27 | 25 |
| 2 | Cadmium and compounds | 810 | 762 |
| 3 | Hexavalent Chromium | 640 | 212 |
| 4 | Lead | 750 | 800 |
| 5 | Manganese and compounds | 32000 | 19640 |
| 6 | Mercury and compounds | 610 | 263 |
| 7 | Nickel | 41000 | 5205 |
| 8 | Selenium | 10000 | 4380 |
| 9 | Copper | – | 35040 |
| 10 | Zinc | – | – |
| 3. Pesticides | Unit (mg/kg) | Unit (mg/kg) | |
| 1 | Atrazine | 110 | 22955 |
| 2 | Chlordane | 110 | 64 |
| 3 | Chlorpyrifos | – | 819 |
| 4 | 2,4-D | 12000 | 7500 |
| 5 | DDT | 120 | 70 |
| 6 | Dieldrin | 1.5 | 1 |
| 7 | Glyphosate | – | 65590 |
| 8 | Heptachlor | 5.5 | 5 |
| 9 | Heptachlor Epoxide | 2.7 | 3 |
| 10 | Lindane | 29 | 21 |
| 11 | Paraquat Dichloride | – | 2950 |
| 12 | Pentachlorophenol | 110 | 36 |
| 4. Others | Unit (mg/kg) | Unit (mg/kg) | |
| 1 | Benzo (a) pyrene | 2.9 | 1.8 |
| 2 | Cyanide and compounds | 35 | 138 |
| 3 | PCBs | 10 | – |
| 4 | Vinyl Chloride | 8.3 | 1.6 |
| 5 | 2,3,7,8-TCDD | – | 0.00002 (20 ng/kg) |
| 6 | PCB-126 | – | 0.001 (1 μg/kg) |
The notification came into force on 12 March 2020.
Download original text of the Notification at
http://www.ratchakitcha.soc.go.th/DATA/PDF/2564/E/054/T_0020.PDF
