The test is delivered without color scale and can be evaluated only with the photometers PF-11!

Normally, the content of fluoride in surface and ground water is lower than 1 mg/l. Permanent consumption of water containing more than 2 mg/l fluoride can cause a drinking water fluorese (a stained discolouration of the tooth enamel). On the other hand a content of fluoride lower than 0.5 mg/l could lead to an increasing risk of caries. The optimal content of fluoride in drinking water is about 1 mg/l. To avoid problems with caries in some countries the content of fluoride in drinking water is artificially increased. However, WHO and EC drinking water regulations recommend a threshold value of 1.5 mg/l F^–. In some European countries, the threshold value for mineral water is also 1.5 mg/l F^–. For the suitability of water for the preparation of baby food a threshold value of 0.7 mg/l F^– is recommended. Natural mineral waters with a fluoride content of more than 5 mg/l must be labelled with a warning.