Water purification tablets offer a portable means of making non-potable water safe to drink, especially during emergencies, travel, or wilderness excursions. These small, lightweight tablets use a measured dose of chlorine to neutralize harmful microorganisms like bacteria, viruses, and Giardia cysts that can cause illness. This guide covers how to select the correct product, where to purchase it, and the proper procedure for treating water.
Selecting the Correct Water Purification Tablets
The first step is recognizing the specific active chemical approved for treating drinking water. The most commonly used compound is Sodium Dichloroisocyanurate, abbreviated as NaDCC, which releases a measured dose of free available chlorine upon dissolving. These tablets are marketed as “water purification tablets,” “potable aqua tablets,” or “emergency water treatment” products and are often certified to standards like NSF/ANSI Standard 60. NaDCC is effective because it releases hypochlorous acid, which is a powerful biocide that oxidizes and kills pathogens in the water.
Avoid common household or pool chemicals, as they are not formulated for safe human consumption. Standard pool chlorine tablets, based on Trichloroisocyanuric acid (Trichlor) or Calcium Hypochlorite, often contain high concentrations of stabilizers like cyanuric acid or other additives unsafe for ingestion. Household bleach, which is a form of sodium hypochlorite, is highly concentrated and may contain non-food grade additives, making accurate and safe dosing difficult. Purchasing products specifically designed for potable water treatment eliminates these risks and ensures the correct, measured dose of disinfectant.
Finding Retail and Online Purchase Locations
Since these tablets are primarily considered a survival, camping, or travel item, specialized retailers stock them rather than typical grocery stores. When searching online, prioritize the full product name, such as “NaDCC water purification tablets” or specific brand names like Aquatabs, instead of generic terms like “chlorine tablets” to avoid pool products. Major e-commerce platforms are reliable sources, but it is wise to verify the seller’s reputation and check the product description for certifications, such as US EPA registration or NSF/ANSI certification.
In-Person Locations
For in-person purchases, check dedicated outdoor and sporting goods stores, which cater to hikers, campers, and preppers. These retailers stock water treatment solutions alongside filters and other survival gear. Pharmacies and drug stores can also be a source, often locating the tablets within the travel health, first aid, or international travel sections. Specialized military surplus or survival preparedness stores also carry these products, sometimes in bulk quantities suitable for long-term emergency kits.
Steps for Treating Water with Chlorine Tablets
Pre-Treatment and Turbidity
Before adding any chemical treatment, address the physical quality of the water, especially if it is cloudy or visibly contaminated. High turbidity, caused by suspended particles like dirt or silt, significantly reduces chlorine effectiveness by shielding microorganisms and consuming the disinfectant. If the water is not clear, filter it through a cloth or allow it to settle until the sediment falls to the bottom. Then, carefully pour off the clearer water for treatment.
Dosing and Mixing
Once the water is relatively clear, follow the instructions on the specific product packaging for the correct dosage. A common ratio is one tablet per liter or quart of water, though this varies based on the tablet’s strength and the water’s contamination level. After dropping the tablet into the water, ensure it fully dissolves, then shake the container briefly to mix the solution completely.
Contact Time and Storage
A minimum contact time must be observed before the water is considered safe to drink, typically 30 minutes, but potentially longer for colder or more suspect water sources. During this waiting period, the chlorine actively works to neutralize pathogens. To maintain the potency of unused tablets for future use, store them in their original sealed packaging, away from direct sunlight, and in a cool, dry place. NaDCC tablets often have a shelf life of up to five years.