CHLORINE, NaDCC, 5kg, granules, pot

Disinfectant used mainly for treating water but also to prepare chlorine solutions for disinfection of surfaces or instruments.

NaDCC granules exist in 2 different chemical forms: anhydrous and dihydrate.

sodium dichloro-s-triazinetrione or sodium troclosene.

Granules of NaDCC (only the dehydrate form is supplied to the field).

These are white crystalline granules with a "slight" odour of chlorine. They have the following characteristics:

Treatment of water

For chlorinating drinking water, a 1% available chlorine stock solution (or "mother solution") is used (= 10 g available chlorine per litre). It is made with 10 x (100/55) = 18 g NaDCC granules (55% available chlorine) for 1 litre of water. The NaDCC granules are fully effervescent.

The stock solution should be kept in an airtight, opaque, non-metallic container, away from light and heat. It should be replaced every week.

Turbid water should first be brought to a turbidity of < 5 NTU before being treated with chlorine. (In acute emergencies, a turbidity of up to 20 NTU is also acceptable).

To achieve this, turbid water should be filtered, clarified or allowed to settle. In urgent situations, water can be treated with a fix dose of 5 mg/l. In other situations the dose of chlorine added to raw water should be adapted to the chlorine demand to obtain a free residual chlorine level of 0.2-0.5 mg/l for a pH < 8 and 0.5-1 mg/l for pH > 8.

See "Public Health Engineering in Precarious Situations", MSF, 2nd edition, 2010:

• T.B. 2.19 Chlorine-generating products
• T.B. 2.21 Batch chlorination of drinking water

Preparation of chlorine solutions

See "Public Health Engineering in Precarious Situations", MSF, 2nd edition, 2010:

• T.B. 2.20 Preparation and use of chlorine solutions for disinfection

Remark

Use a pool-tester to check the presence of free residual chlorine.

See "Public Health Engineering in Precarious Situations", MSF, 2nd edition, 2010:

• T.B. 2.22 Monitoring chlorination