Taylor Drop Test Kit, Chlorine (Bleach), 1 drop = 10 or 100 ppm; 1 drop = 0.05 or 0.5%

Taylor Drop Test Kit, Chlorine (Bleach), 1 drop = 10 or 100 ppm; 1 drop = 0.05 or 0.5%

Chlorine or chlorine compounds are routinely used as sanitizers, oxidizers, and bleaching agents in commercial, industrial, and water-utility operations. The treatment may be applied as a gas or as a dry formulation such as a tablet or granules, but for many purposes the liquid bleach sodium hypochlorite (NaOCl) is best. Sodium hypochlorite is formed by reacting chlorine with sodium hydroxide. It is sold based on the strength of the product— typically, in these markets, 12–15% available chlorine content.

Liquid, gas, and dry forms of chlorine are used to treat pool water too, so it is sparkling clean and pathogen-free for safe swimming. The most common treatment for regulated pools is also sodium hypochlorite, called “pool bleach” by the trade. It’s popular because of the convenience of feeding a liquid and because it costs less than other options. The available chlorine content of full-strength pool bleach should be 10–12%, roughly double the strength of household laundry bleach.

However, sodium hypochlorite is not chemically stable and decomposes while in transit and storage. It degrades even faster when exposed to heat and light. As it loses its strength, more has to be applied to achieve the desired residual, thus negating the economy of buying the liquid disinfectant. If you buy bleach in bulk, use Taylor’s Chlorine Bleach Drop Test (K-1579) at the time of delivery to verify the available chlorine content meets the labeled concentration. Make sure you’re getting the full strength you’re paying for! As part of routine maintenance, also test stored bleach periodically.

The K-1579 is the only single-analyte kit in Taylor’s product line designed for measuring the high chlorine concentrations found in sodium hypochlorite bleach solutions. Two of our color-matching tests that utilize orthotolidine will go as high as 250 parts per million (ppm) of total chlorine, the K-1151 and K-1401. A wide-range test paper, part #6023 made by Precision Laboratories, can be used to approximate total chlorine at 10, 50, 100, and 200 ppm; and an FAS-DPD drop-count titration, K-1515, can measure up to 20 ppm of free or combined chlorine when 1 drop = 0.5 ppm. By comparison, in this bleach kit, instructions are provided for chlorine concentrations in the range of 10–100 ppm. 1 drop = 10 or 100 ppm/0.05 or 0.5% available chlorine (Cl2).

This kit is not appropriate for testing the chlorine residual in pool or spa water.