RESUMEN
The purpose of study was to evaluate and compare chemical quality of Iranian bottled drinking water reported on manufacturer's labeling and standards. This study was a cross-sectional descriptive study and done during July to December 2008. The bottled mineral water collected from shops randomly were analyzed using all parameters address on manufacturer's labeling and the results were compared with the manufacturers' labeling data, WHO Guideline Values, USEPA Maximum Contaminant Levels and the maximum contaminant levels of drinking water imposed by the Iranian legislation. Statistical analysis on data was done with the Kolmogorov-Smirnov test for normal distribution, the paired t-test to compare the data with manufacturer's labeling and the one-sample t-test to compare with standard and MCL values at P<0.05 of confidence level. The results showed a statistically significant difference with manufacturer's labeling values, however there was no significant difference between the values of magnesium and pH and manufacturers' labeling values [P>0.05]. In addition, ph and calcium values were significantly higher that their proposed values indicated by Iranian National Legislation and international MCLs [P<0.05]. Our results are extremely important for the health supervisory agencies such as Ministry of Health and Institute of Standards and Industrial Research of Iran to have more effective controls on bottled water industries, and to improve periodical the proposed standard values