FOR PHYSICOCHEMICAL PARAMETERS
Undesirable Substances | Toxic/Heavy Metals | Pesticide Residues | TDS | pH | Turbidity | Colour
Apart from the toxic metals and substances, there are a few undesirable substances that can make drinking water unhealthy/unhygienic or hamper its taste. All these undesirable substances were tested as per the requirements of IS, and a handful of brands contained some of these in negligible quantities. • All brands were found to be within the limits set by Indian Standard for these substances: aluminium, anionic surface-active agents, antimony, barium, borates, copper, iron, manganese, mineral oil, nitrite, phenolic compounds, residual chlorine, selenium, sulphide and zinc. • Nitrate (as NO ): Nitrate in drinking water 3 can be a maximum of 45 mg/litre. Except for Aquafina, Kinley and More, all brands contained some amount of nitrate, but it was well within the maximum permissible limit.
• Fluoride (as F): As per the national standard, the maximum amount of fluoride permissible in packaged drinking water is 1 mg/litre. All brands were found to be within the permissible limit.
• Silver (as Ag): Levels of silver up to 0.1 mg/litre can be tolerated without risk to health. Silver was not detected in any of the tested brands.
• Chloride (as Cl): The maximum permissible limit for chloride is 200 mg/litre. Chloride was well below the maximum permissible limit in all tested brands. • Sulphate (as SO ): The permissible limit for 4 sulphate is 200 mg/litre. It was well below the
maximum permissible limit in some of the brands, while in some it was not detected at all. Alkalinity (as HCO ): Alkalinity is not 3 considered to be detrimental to humans, but is generally associated with hardness, high pH values and excessive dissolved solids, all of which may be undesirable. HCO3 should not exceed 200 mg per litre. All the brands were found well below the permissible limit for alkalinity Calcium (as Ca) and Magnesium (as Mg): Calcium in water and certain other minerals in water are healthy. Calcium-rich water has a higher pH and that is better than drinking acidic water. However, calcium and magnesium are components of permanent hardness, and thus are undesirable in drinking water. The amount of calcium should not exceed 75 mg per litre, while magnesium should not be more than 30 mg per litre. In the tests, all brands were found to contain very slight amounts of calcium and magnesium
Sodium (as Na): Sodium is an essential mineral in our diet. It is commonly found in the form of sodium chloride (salt). Salt has no smell and it dissolves easily in water and gives water a salty taste at high levels. The amount of sodium should not exceed 200 mg per litre. All the brands were found well within the maximum permissible limit for sodium.
As per the national standard, the toxic substances that should not be present in drinking water include mercury, cadmium, arsenic, cyanide, lead, chromium and nickel. All the brands passed these tests as none of the said substances was detected.
Pesticide is a chemical or biological agent (such as a virus, bacterium, antimicrobial, or disinfectant) that deters, incapacitates, kills, or otherwise discourages pests. Pesticides may cause acute and delayed health effects in people who are exposed. Such adverse health effects range from simple irritation of the skin and eyes to more severe effects like affecting the nervous system, mimicking hormones causing reproductive problems, and causing cancer.
As per Indian Standard, the maximum permissible limit is 0.0001 mg/litre for individual pesticide and 0.0005 mg/litre for total pesticide residues. All tested brands were within the requirement set by the national standard. Traces of 2,4-dichlorophenoxyacetic acid were found in four brands but these were well below the specified limit.
Total Dissolved Solids (TDS)
Total dissolved solids are the amount of minerals, salts or metals dissolved in a given volume of water. TDS is directly related to the purity of potable water and the quality of water purification systems, and affects everything that consumes, lives in, or uses water, whether organic or inorganic, whether for better or for worse. The standard/regular practice of packaged drinking water in industry is to take the potable water from a regular source (for example, groundwater or as permitted by the Indian Standard) and demineralise the water through the RO system and in the required quantity to balance the TDS level as permitted in the national standard.
As per Indian Standard, total dissolved solids in packaged drinking water shall be a maximum 500 mg/ litre. • TDS in all brands was lower than the maximum permissible limit. Rail Neer was found to contain the highest quantity of TDS (126 mg/litre) and Aquafina the lowest (9 mg/litre). Consumer Voice
suggests that there be a lower-side limit for TDS – no TDS means there are no minerals as well. Water with extremely low concentrations of TDS may also be unacceptable because of its flat taste.
The pH level of your drinking water reflects how acidic it is. pH stands for ‘potential
hydrogen’, referring to the amount of hydrogen mixed with the water. pH is measured on a scale that runs from 0 to 14. A measurement of seven is neutral, indicating there is no acid or alkalinity. A measurement below 7 indicates presence of acid and a measurement above 7 indicates alkalinity. The normal range for pH in packaged drinking water as per Indian Standard is between 6.5 and 8.5. All the brands of packaged drinking water were within the specified range for pH. Turbidity
Turbidity is a principal physical characteristic of water. It is caused by suspended matter or impurities that interfere with the clarity of the water. These impurities may include clay, silt, finely divided inorganic and organic matter, and soluble coloured organic compounds.
Turbidity in water shall not be more than 2 nephelometric turbidity units (NTU). Turbidity was not detected in any of the brands. They were all free of suspended matters and impurities.
Colour (in hazen unit)
• Colour was not detected in any of the brands and they were all given full scores.
FOR SENSORY ATTRIBUTES
The sensory test was conducted in a reputed lab by qualified and experienced members who were capable of judging the sensory attributes of such products. • Aquafina, Bailley, Royal Blue and A4X were not included in the sensory test for taste as they had failed the microbiological test and could be unsafe to drink. • The remaining eight brands scored equally well on
odour and taste parameters.
FOR GENERAL QUALITIES Marking/Labelling
The bottle of packaged drinking water should be legibly marked with these details: a) name of the product; b) name and address of processor; c) brand name, if any; d) batch or code number; e) date of processing/packaging; f) treatment of disinfection, if any; g) ‘best before’ date; and h) mandatory ISI mark , MRP, net volume, FSSAI license number and customer care details. • All the brands were found to have the marking/labelling requirements and hence were given full scores. All the brands were marked with ISI mark. • The green dot (indicating vegetarian status) is not a mandatory requirement and some brands do not carry it.
The packaging material of packaged drinking water should be of food-grade material and the cap of the bottle must not have any colour migration on the product. Expert panellists judged the packaging based on ease of use, handling and other related parameters, and ratings were given accordingly. All the brands were in PET plastic bottle. Packaging of all brands was found to be convenient and acceptable.
As a matter of policy, before publication, the test results of the brands are shared with their respective manufacturers/marketers inviting their views/ comments. We reproduce here the comments of manufacturers as well as our reply: