Cleaning, Sanitizing, and Disinfecting
Know what each step does, when each is required, and how to use chemicals safely and effectively.
Table of contents
Cleaning, sanitizing, and disinfecting are three different jobs. People use the words as if they mean the same thing, but they do not. A surface can look spotless and still carry germs, and a disinfectant sprayed on a dirty counter may do very little. Knowing which step you need, and doing it in the right order, is what actually protects people. It also keeps you from wasting chemicals or harming yourself with them. This applies in a restaurant kitchen, a classroom, a restroom, or a clinic.
What You Will Be Able to Do
- Explain what cleaning, sanitizing, and disinfecting each do
- Choose the right step for a surface and a situation
- Read a product label for its dilution, contact time, and limits
- Keep a surface wet for the full contact time
- Avoid dangerous chemical mixes and protect yourself while you work
The Three Steps
| Step | What it does | When you use it |
|---|---|---|
| Cleaning | Removes dirt, grease, and many germs with soap or detergent and scrubbing | Always first, on every surface |
| Sanitizing | Lowers germs to a level public health standards consider safe | Food-contact surfaces, dishes, toys that go in mouths |
| Disinfecting | Kills most of the germs listed on the label | Restrooms, high-touch surfaces, and body fluid cleanup |
Cleaning does not need to kill anything. It lifts soil off the surface so it can be wiped or rinsed away. Soap, water, and rubbing remove a large share of germs on their own.
Sanitizing reduces germs quickly but does not claim to kill everything. In the United States, the Environmental Protection Agency (EPA) registers sanitizers. Standards differ by use, and a product made for food-contact surfaces is tested differently from one made for other surfaces. Use a product labeled for the surface in front of you.
Disinfecting is stronger. A disinfectant is tested to kill specific germs listed on its label, in a specific time. It may need a rinse afterward, especially on anything that touches food or mouths.
Sterilizing is a fourth level that destroys all microbes, including spores. It is done with special equipment in healthcare and labs. A spray bottle does not sterilize anything.
Why Order Matters
Clean first, then sanitize or disinfect. Dirt, grease, and food soil shield germs and can use up the active chemical before it reaches them. A disinfectant sprayed over grime gives a false sense of safety.
- Remove loose debris.
- Clean with detergent and water, scrubbing as needed.
- Rinse if the label or your procedure calls for it.
- Apply the sanitizer or disinfectant.
- Leave it wet for the full contact time.
- Air dry, or wipe or rinse if the label says to.
A few products are labeled as one-step cleaner-disinfectants. They can do both on lightly soiled surfaces if the label says so. On visibly dirty surfaces, clean first anyway.
Reading the Label
The label on an EPA-registered product is a legal document. It tells you exactly how the product was tested and how to get the result it claims. Check five things:
- Use: Does it say sanitizer, disinfectant, or both? Is it approved for your surface, and for food-contact surfaces if that is what you are working on?
- Germs it kills: Disinfectant labels list them. In a healthcare setting, your facility's infection prevention team decides what is required.
- Dilution: How much concentrate goes in how much water. More is not stronger in any useful way. Extra chemical wastes money, can leave a sticky film, and can hurt you. Less may not work.
- Contact time: How long the surface must stay wet. This is also called dwell time.
- Safety: Required protective gear, first aid, and what not to use it on. For more detail, the Safety Data Sheet (SDS) lists hazards, spill steps, and storage.
Contact Time
Contact time is the rule people break most often. Germs are not killed the moment a product lands. The surface has to stay wet for the time on the label. Depending on the product, that may be anywhere from under a minute to 10 minutes.
If you spray and immediately wipe, you have cleaned the surface, not disinfected it. If the product dries early, apply more so the surface stays wet for the full time.
Worked example. A restroom disinfectant has a 5-minute contact time. Spray the sinks, toilets, and partitions first. Then restock paper and empty the trash, which takes about 6 minutes. When you come back to wipe, the full time has passed and you have lost no time at all. Build contact time into your routine this way.
Mixing to the Right Strength
Use a dilution system or a measuring cup. Do not pour by eye.
Worked example. A label calls for 2 ounces of concentrate per gallon of water. You are filling a 2.5-gallon bucket. Multiply 2 ounces x 2.5 gallons to get 5 ounces of concentrate. Add the water first if you can, then the chemical, to reduce splashing and foam.
Mix only what you need, and mix it fresh when the product requires it. Bleach solutions weaken over time, so many procedures call for a new batch each day. Household bleach also comes in different strengths, and only some products are registered for disinfecting. Follow the label on your exact product or your site's written procedure. Do not reuse a recipe you learned somewhere else.
Some sanitizers must be checked with test strips. Food-service sanitizer solutions, for example, must be held in a set concentration range. A solution that is too weak will not work. One that is too strong can leave chemical residue on food-contact surfaces.
Label every spray bottle and bucket with the product's name, even if you will use it right away. An unmarked bottle is how people get hurt and how chemicals get mixed by mistake.
Chemical Safety
Warning: Never mix bleach with ammonia, acids, or other cleaners. Bleach and ammonia make chloramine gas. Bleach and acid, including many toilet bowl and descaling products, make chlorine gas. Both can cause serious lung injury or death in a small room.
- Use one product at a time. Rinse a surface before you switch products.
- Wear what the label requires. Chemical-resistant gloves and eye protection are the usual minimum for handling concentrates.
- Ventilate. Open a door or run the exhaust fan when you use strong products.
- Do not use a chemical on a surface that the label excludes. Some products damage stone, metal, or finished floors.
- Keep products in their labeled containers, closed, and out of reach of children and away from food.
- Know what to do after exposure. Check the first aid section on the label. For eyes, use an eyewash or clean running water right away and get medical help as directed. If someone is feeling ill after breathing fumes, move them to fresh air and call for help.
If you begin coughing or your eyes burn, leave the area, tell someone, and do not go back until it is aired out.
When Each Step Is Required
Your site's rules come first. Food, childcare, and healthcare settings each have regulators who may require specific products and schedules.
| Situation | Minimum step |
|---|---|
| Desks, shelves, floors, and windows in an office | Clean |
| Dishes, cutting boards, and food prep surfaces | Clean, rinse, then sanitize |
| Toys that go in mouths, high chair trays | Clean, rinse, then sanitize |
| Restrooms, sinks, toilets, door handles | Clean, then disinfect |
| Diaper changing surfaces | Clean, then disinfect |
| Blood, vomit, or other body fluids | Follow your spill procedure and use protective gear |
Disinfecting everything all the time is not better. It adds chemical exposure for no benefit on surfaces that are not high risk. Match the step to the need.
Tools Matter Too
A dirty cloth spreads germs from one surface to the next. Use a fresh cloth or a clean side for each area, and change mop water or solution before it looks dirty. Keep cloths for toilets separate from cloths for anything else. Microfiber holds soil well, but some disinfectants lose strength when they soak in certain fabrics, so check the product and cloth directions. Wash your hands after you take off your gloves, because gloves can tear and hands can pick up germs as you remove them.
Common Mistakes
| Mistake | What it costs |
|---|---|
| Disinfecting without cleaning first | The chemical cannot reach the germs |
| Wiping before the contact time ends | You cleaned, but you did not disinfect |
| Adding extra concentrate | Residue, damaged surfaces, irritated lungs and skin |
| Mixing products to make them stronger | Toxic gas |
| Reusing one cloth across a whole room | Germs move from dirty areas to clean ones |
| Using a non-food-rated product on food surfaces | Chemical contamination of food |
Check Your Understanding
1. A coworker sprays disinfectant on a greasy counter and wipes it off right away. What went wrong?
Two things. The grease should have been cleaned off first, and the disinfectant was removed before its contact time. The counter was neither properly cleaned nor disinfected.
2. Your disinfectant has a 10-minute contact time, but it dries on the sink in 4 minutes. What do you do?
Apply more so the surface stays wet for the full 10 minutes. If that keeps happening, ask whether a product with a shorter contact time is available.
3. A label says 1 ounce of concentrate per gallon. You need 3 gallons of solution. How much do you add?
Multiply 1 ounce x 3 gallons to get 3 ounces. Measure it. Adding more will not clean better.
4. A bottle has no label, but it smells like bleach. You need more of it, so you plan to top it up from a jug. What should you do?
Do not use or fill an unlabeled bottle. You do not know what is inside, and adding bleach to the wrong chemical can make toxic gas. Report it to your supervisor so it can be dealt with safely. Then use a labeled bottle.
Key Takeaways
- Cleaning removes soil, sanitizing lowers germs to a safe level, and disinfecting kills the germs on the label.
- Always clean first. Chemicals cannot work through dirt.
- The surface must stay wet for the full contact time on the label.
- Measure your dilution. More chemical is not better.
- Never mix bleach with ammonia, acids, or other cleaners.
- Label every container and wear what the label requires.