Water · Water Treatment
Chlorine in a dropper bottle — the same chemistry as household bleach in a pre-measured, field-portable format. Here is what exists, what does not, and how to dose it correctly.
The basics
Sodium hypochlorite is the active ingredient in household bleach. When you read instructions to treat emergency water with bleach, you are using sodium hypochlorite. A "treatment drop" product in this category is essentially a pre-measured, stabilized sodium hypochlorite solution in a small dropper bottle — the same chemistry, packaged for portability and precise dosing.
The honest answer about this product category: the dedicated retail market for pre-measured sodium hypochlorite dropper products is thin. Most preparedness-specific sodium hypochlorite products fall into two distinct buckets that already have their own NWS pages: household bleach (broad-concentration, stored at home) and Water Preserver Concentrate (stabilized sodium hypochlorite formulated specifically for long-term water storage). This page focuses on what distinguishes dropper-format products from those two options and when each makes sense.
For field water treatment, the EPA and CDC recommend unscented household bleach with a measuring dropper — which is essentially the same setup as a purpose-made drop product. The dropper matters as much as the bottle. If you already have bleach at home, a clean medical dropper from a pharmacy gives you the same capability as a purpose-made kit.
Quantity guidance
For field water treatment, a single 2-ounce dropper bottle of sodium hypochlorite (or a small medical dropper paired with a gallon of bleach) can treat hundreds of gallons. Stock is rarely the constraint. The main variables are concentration, age of the bleach, and whether you have a dropper to measure accurately.
| Format | Treats (approx.) | Baseline stock |
|---|---|---|
| 1 gallon household bleach (6%) | ~3,800 gallons clear water | 1 gallon per household |
| Dropper bottle product (2 oz) | ~100–200 gallons | 1 bottle in go-bag |
| Water Preserver Concentrate (16 oz) | Up to 55 gallons stored | 1 bottle per 55-gal barrel |
Note on role: Sodium hypochlorite in any format does not kill Cryptosporidium at normal treatment doses. If your water source carries Crypto risk (surface water, flood-affected wells), use chlorine dioxide tablets or drops, or a mechanical filter rated for parasites. Bleach-based treatment is most reliable for municipal water that has lost pressure, or for stored water that was originally potable.
Storage
Sodium hypochlorite degrades over time. An unopened gallon of household bleach stored at room temperature has a usable life of 6 to 12 months from manufacture. After that, the active chlorine concentration drops below the level needed for reliable water disinfection.
Pre-packaged treatment drops in sealed dropper bottles may hold potency longer than an opened jug of bleach, but they are still sodium hypochlorite and subject to the same chemistry. Check the manufacture date on any pre-packaged product before relying on it.
Store all sodium hypochlorite products in a cool, dark location. Heat and light accelerate degradation. Do not transfer bleach to a clear container. Do not use expired bleach as your primary treatment without increasing the dose and confirming the water smells faintly of chlorine after treatment.
After treating water and waiting 30 minutes, the water should have a faint chlorine smell. If it does not, the bleach may have degraded, the dose was insufficient, or the water had unusually high organic content. Re-dose, stir, and wait another 15 minutes. If still no chlorine smell after a second dose, switch to a different treatment method.
What to buy
All three options below use sodium hypochlorite. The choice depends on whether you are treating stored water at home, need a portable field option, or need water disinfection plus long-term preservation.
Unscented 6% or 8.25% bleach with a pharmacy-grade measuring dropper. The setup recommended by EPA and CDC. Cheap, widely available, large volume.
Best for: home water treatment
Small sodium hypochlorite drops in a sealed dropper bottle. Limited retail market — verify EPA registration and concentration before buying any specific product.
Best for: go-bag or vehicle kit
Stabilized sodium hypochlorite formulated for long-term water storage. Extends treated water shelf life to 5 years when added to sealed food-grade containers at storage.
Best for: treating stored barrels and containers
NWS recommendation: For go-bags and field kits, chlorine dioxide tablets or drops (Aquamira) provide broader pathogen coverage and are the better portable option. Sodium hypochlorite products are most useful at home for large-volume treatment and stored water. Water Preserver Concentrate handles the stored water case specifically. Keep a gallon of unscented bleach with a measuring dropper as a home backup — it is all you need for this chemistry at home.
Safety & dosing
The correct dose depends entirely on the sodium hypochlorite concentration of your product. The tables below cover the two most common concentrations found in U.S. retail bleach. For a pre-packaged dropper product, follow the label — the concentration will determine the correct dose.
| Bleach concentration | Drops per liter (clear water) | Drops per liter (cloudy water) | Wait time |
|---|---|---|---|
| 6% sodium hypochlorite | 2 drops | 4 drops | 30 minutes |
| 8.25% sodium hypochlorite | 1.5 drops | 3 drops | 30 minutes |
Per EPA emergency disinfection guidance (EPA: Emergency Disinfection of Drinking Water) and CDC (CDC: Water in an Emergency). Verified June 2026.
Sodium hypochlorite at standard treatment doses does not reliably kill Cryptosporidium. Crypto is a parasite with a tough outer shell that chlorine does not penetrate easily. For water from surface sources (streams, ponds, floodwater) or a well that has been flooded, use chlorine dioxide or a filter rated for Cryptosporidium. Bleach-based treatment is reliable for water that was originally potable — municipal water with compromised pressure, stored water, or rainwater that has been filtered.
Only plain, unscented chlorine bleach is safe for water treatment. Do not use scented bleach, color-safe bleach, or any bleach with added cleaners or thickeners. The label must say the active ingredient is sodium hypochlorite at 5% to 9% concentration. If the label does not specify this, do not use it for water treatment.
Where to buy
Home storage pick
Any grocery store, warehouse club, or hardware store
Clorox Regular Unscented (8.25%) or store-brand unscented bleach (6%). Buy fresh within the year. Use with a measuring dropper. One gallon treats thousands of gallons of clear water.
$3 – $6 per gallon
Read full bleach guideLong-term storage pick
Stabilized sodium hypochlorite for water storage
EPA-registered formula that extends stored water shelf life to 5 years. Add to sealed food-grade containers at the time of storage. Not a field treatment product.
$10 – $15 per bottle
Read full guideAffiliate disclosure: New World Survival earns a small commission on purchases made through links on this page, at no cost to you. We only recommend products we would stock in our own kit.
Related
Sodium hypochlorite is one layer in a complete water preparedness system. For the broadest pathogen coverage, pair it with a mechanical filter and a chlorine dioxide option for Crypto-risk situations.
The full guide to bleach dosing, concentration differences, and limits.
Broader coverage including Cryptosporidium — the stronger portable option.
Sodium hypochlorite formulated for 5-year stored water treatment.