The Department of Medical Sciences (DMS) surveyed the quality of fish sauces and mixed fish sauces sold in fresh markets and department stores nationwide.
It collected 471 samples produced by 118 manufacturers in February and March.
Of the samples, 242 were fish sauces priced at Bt10-Bt45, and 229 were mixed fish sauces costing Bt6-Bt18.
The survey found that only 62.8 per cent of fish sauces and 37.1 per cent of mixed fish sauces met safety standards.