Ebola Chlorine Solutions Explained: 0.05%, 0.5% and 2% and What Each Is For

Tony Miller

6 days ago

7 min read

Ebola protocols use two chlorine strengths. A 0.5% solution (5,000 ppm available chlorine) is for spills, surfaces, gloved hands, reusable equipment and waste. A 0.05% solution (500 ppm) is for bare skin and linen. The WHO and MSF documents we read give a 2% solution no role.

Which chlorine strength is used for what in an Ebola response?

Use the stronger solution on things, the weaker one on people and fabric. The MSF Filovirus Haemorrhagic Fever Guideline (2008), Table 4 lays out the split.

At 0.5%, MSF lists body fluids, excreta and vomit, corpses, toilets and bathrooms, gloved hands, floors, beds and mattress covers, and footbaths. At 0.05% it lists bare hands, skin and shoes, thermometers, laundry, and plates, cups and eating utensils.

The WHO interim IPC guidance for filovirus haemorrhagic fever (December 2014) agrees on the 0.5% side and adds contact times:

Contaminated surfaces and objects: clean first, then disinfect with 0.5% (5,000 ppm), because organic matter inactivates the disinfectant.
Reusable goggles and face shields: clean with water and detergent, then immerse fully in 0.5% for a minimum of 10 minutes, then rinse thoroughly with water.
Gum boots: stand in a bowl of 0.5% for at least one minute, and soak in 0.5% for 30 minutes at least once a day.
Waste trolleys and bins: disinfect all surfaces with 0.5% after each use.
Body bags: wipe the outside of each bag with a suitable disinfectant, with 0.5% given as the example.

At 0.05% the same WHO document covers linen. Where linen is laundered at low temperature, wash with detergent, rinse, then soak in 0.05% (500 ppm) for approximately 15 minutes. MSF adds that discharged patients' clothes are soaked for 30 minutes in 0.05%.

Spills have their own routine in the MSF guideline. Pour 0.5% solution with a cup to cover the fluid completely, do not use sprayers because they form droplets, let it stand for 15 minutes, remove with a rag or paper towel into infected waste, then wash the area with soap and water.

What about the 2% solution in the title?

We could not confirm a 2% solution in any WHO or MSF document read for this article. Neither the WHO 2014 guidance nor the MSF 2008 guideline uses 2% anywhere; both use only 0.5% and 0.05%. The title carries 2% because people search for it.

If your agency's protocol specifies a 2% solution, for example as a concentrated stock to dilute or for a specific task, follow that protocol and ask its authors what it is for. We will not guess a use case. A stronger solution is not a safer one. MSF warns that chlorine solutions weaken gloves and that strong solutions are very aggressive on skin and eyes.

Is chlorine still the way to wash hands?

Not first choice. WHO says alcohol-based handrub is the standard of care and soap with running water is the fallback. Where chlorine is currently used for hand hygiene, WHO recommends changing to handrub or soap and water, and allows chlorine hand solutions only in the interim in emergencies until those become available.

MSF's older guideline still shows 0.05% hand-washing points at staff entry and exit. Read both documents together: a 0.05% hand station is a stopgap, and the permanent fix is a water supply that can sustain soap and running water.

WHO also discourages spraying clinical areas with disinfectant and says that spraying people wearing PPE or street clothes, and routine spraying of rooms, is not recommended. It may be accepted outdoors, for example when a burial team decontaminates a household, as the only feasible option. Spraying must follow cleaning with water and detergent.

How do you make 0.5% and 0.05% solutions?

Start from a product of known strength. MSF Annex 12 names HTH (calcium hypochlorite) granules at 65 to 70% active chlorine as the recommended product, because it is stable. Its worked amounts:

0.5% from HTH-70%: one 500 g pot for 60 litres, two 500 g pots for 120 litres. MSF notes the results are slightly stronger than 0.5%, because daily convenience matters more than exact strength.
Stir the HTH into clean water, let the white sludge settle, use the clear liquid, and discard the sludge into a soakaway or sewer.
NaDCC tablets of 1.5 g available chlorine: 35 tablets in a 10 litre bucket for 0.5%, and 3.5 tablets in 10 litres for 0.05%. We have left out the guideline's 20 litre row, which does not scale from the 10 litre row as printed. Check any NaDCC figure against the tablet manufacturer's stated available chlorine.
Other products, such as household bleach: MSF gives the formula grams of product = 10 x (100 / product strength %) x required strength % x volume in litres. Its example is 15 litres of 4% bleach for 120 litres of 0.5%.

By our own arithmetic from that formula, 4% bleach makes 0.05% at one tenth of that quantity, 1.5 kg for 120 litres. Treat this as a check, not a replacement for your protocol.

Handling rules from the same annex:

Wear protective clothing and prepare solutions in a well-ventilated area, preferably outdoors.
Use plastic containers and equipment.
Do not keep solution for more than 24 hours; if it is a day old, dispose of it in a soakaway or latrine. WHO likewise says to prepare locally made solutions every day.
Store products in closed plastic containers, cool and shaded. If you rely on a manufacturer's stated strength, the product must be no older than three months and its storage history known.

The WHO document's Annex 6, "How to make chlorine solutions for environmental disinfection", is supplied as an image in the file we read, so we have carried none of its figures.

Where does the water come from?

Mixing is the small part of the demand. MSF's guideline says water use depends mainly on how many staff work in the isolation area, not on how many patients there are, and plans for approximately 70 litres of water per day per staff member working in protective clothing. That water covers cleaning, laundry, 0.5% and 0.05% solutions, footbaths, and disinfection of PPE and surfaces. It also requires clear water: turbidity below 5 NTU for drinking water and for preparing chlorine solutions.

This is where the WASH supply side bites. A solution made with turbid water is weaker than the label says, a tank that runs dry stops the hand station and the footbath together, and a site with a few dozen staff in PPE needs thousands of litres a day by MSF's planning figure. Our view: size storage from staff numbers first and bed numbers second, and put the tank where it can be filled and kept covered.

What does SLS supply, and what does it not?

SLS is the in-country authorised distributor of Aquatabs (Medentech/Kersia), P&G Purifier of Water, and Oxfam and Butyl water tanks, with stock in Juba. For this topic, that means the water behind the solutions, and storage for it.

We do not supply chlorine solutions, HTH, sprayers, PPE or medical equipment. Aquatabs 67mg is a drinking-water tablet: one tablet treats 8 to 10 litres of clear water with 30 minutes of contact, per the CDC and Medentech instruction sheet. It is not the 1.5 g tablet in the MSF table and cannot stand in for it.

Nothing here replaces your facility's IPC protocol. Concentrations and contact times differ between agencies and over time, the WHO guidance read here is dated 2014, and you must follow your own agency's current guidance.

Why does IPC water supply matter right now?

The WHO Disease Outbreak News of 1 August 2026 reported 3,605 confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo as of 30 July 2026, with persistent challenges in implementing infection prevention and control in health-care facilities and 151 confirmed cases among health workers. This is a dated snapshot, not the current count; check WHO for the latest.

A health worker infection is often a failure of a routine: a hand station that ran dry, a footbath not refreshed, a solution mixed in turbid water. Those are supply problems before they are training problems. Teams planning sites across DRC and neighbouring countries can see what SLS has delivered in the region.

Frequently asked questions

What chlorine solution is used for Ebola?

Two strengths: 0.5% (5,000 ppm) for surfaces, spills, gloved hands, reusable equipment, waste and corpses, and 0.05% (500 ppm) for bare skin, laundry and utensils, per the MSF Filovirus Haemorrhagic Fever Guideline and the WHO interim IPC guidance.

Is 0.05% or 0.5% chlorine used on hands?

MSF lists 0.05% for bare hands and 0.5% for gloved hands. WHO says alcohol-based handrub or soap and running water is the standard, and chlorine hand solutions are an interim measure only, per the WHO interim IPC guidance (2014).

How long should chlorine solution for Ebola be kept?

No more than 24 hours, per MSF Annex 12, which says to dispose of day-old solution in a soakaway or latrine. WHO says to prepare locally made solutions every day.

Is there a 2% chlorine solution for Ebola?

We could not find one in the WHO 2014 interim guidance or the MSF 2008 guideline, which use only 0.5% and 0.05%. If your agency's protocol specifies 2%, follow that protocol.