. In this study examination of label information physical and microbiological qualities was performed in 30 clear-plastic and 3 opaque-plastic bottled drinking water products distributed in city municipality of Ubon Ratchathani. Results showed that 12 clear-plastic (36%) and 3 opaque-plastic (9%) bottled drinking water samples had no expiry date on the product labels which were discordant to the criteria for drinking water in sealed containers imposed by the Ministry of Public Health of Thailand no. 383 (2017). Odorless appearances of all drinking water samples were observed. Values of pH in 4 clear-plastic (12%) and 3 opaque-plastic (9%) bottled drinking water samples were in the ranges of 6.21±0.00–6.29±0.03 which were below the allowable limit (pH 6.5–8.5). All bottled drinking water products contained numbers of total coliform and fecal coliform bacteria less than 2 MPN/100 mL and were devoid of E. coli. Therefore based on the quality of clear-plastic and opaqueplastic bottled drinking water products distributed in city municipality of Ubon Ratchathani 1 5 samples (45%) did not meet standard for drinking water in sealed containers declared by the Ministry of Public Health of Thailand (1981 and 2017) owing to no expiry date labeled on the products and pH value below 6.5.

In this study pH physical and microbiological qualities of clear and opaque plastic bottled drinking water produced in Buriram Province Thailand were investigated. Samples of bottled drinking water (N=22) were 8 clear plastic bottles and 14 opaque plastic bottles. Results showed that pH value of all samples were in a range of 6.04 ± 0.03 to 7.61 ± 0.01 in which 7 samples were not acceptable according to the criteria for drinking water in sealed containers declared by the Ministry of Public Health of Thailand. Coliform bacteria in all tested samples were less than 1.8 MPN/100mL and none of E. coli was detected. Therefore consumers of bottled drinking water produced from Buriram province should be aware of health safety because some drinking water products were unacceptable in terms of pH value.