Disinfecting vs sanitizing vs cleaning: what each one means

A spray bottle says "kills 99 percent of germs", a colleague says the desks were "sanitized", and a notice in a washroom says the room was "cleaned". Are those the same thing? They are not, and mixing them up leads people to do too little in some places and far too much in others. This page lays out how CDC and EPA define cleaning, sanitizing and disinfecting, why cleaning has to come first, what contact time and EPA registration numbers mean on a label, and how to think about which job fits a home or a workplace. For the mechanics of cleaning itself, start with how cleaning works.

What the agencies mean by each word

CDC defines the three in its home cleaning guidance. Cleaning removes most germs, dirt and impurities from surfaces and is done with water, soap and scrubbing. Sanitizing reduces germs to levels that public health codes or regulations consider safe, and is done with weaker bleach solutions or sanitizing sprays. Disinfecting kills most germs on surfaces and objects, and is done with stronger bleach solutions or chemicals (CDC, When and How to Clean and Disinfect Your Home).

EPA adds a regulatory view, because the products that sanitize and disinfect are pesticides in the legal sense. Its comparison table says cleaning removes dirt and organic matter using soap or detergents. Sanitizing kills bacteria on surfaces using chemicals and is not intended to kill viruses. Disinfecting kills viruses and bacteria on surfaces using chemicals. EPA also states that surface disinfectants face more rigorous testing and must clear a higher bar for effectiveness than surface sanitizers, and that many products are registered as both because they were tested both ways (EPA, What's the difference between products that disinfect, sanitize, and clean surfaces?).

One consequence is worth noticing. EPA regulates a cleaning product only if it makes a sanitizing or disinfecting claim, so an ordinary detergent with no germ claim is outside that registration system.

Why cleaning comes first

CDC's reasoning is direct: surfaces should be cleaned before they are sanitized or disinfected because impurities like dirt may make it harder for chemicals to get to and kill germs. It adds that cleaning alone removes most harmful viruses or bacteria from surfaces. CDC says to clean using a product suitable for each surface and to follow the instructions on the product label (CDC).

This also explains a common frustration. A disinfectant sprayed over visible dirt and wiped away at once has had little chance to work. Washing first, then applying the disinfectant to a cleaner surface, follows the CDC order of work.

Contact time, labels and EPA registration

A disinfectant works over time, not instantly. CDC says to leave the disinfectant on the surface long enough to kill the germs, which is called the contact time, and that the surface should stay wet for the entire period. EPA's registered-disinfectant page gives a worked example: if a label specifies a contact time of 10 minutes, the surface should remain visibly wet for at least 10 minutes, and if it is no longer wet after 5 minutes, more product should be applied (EPA, Selected EPA-Registered Disinfectants).

The same EPA page explains how to read a registration number. Each label carries one, made of two or three parts separated by dashes, and it is the only reliable way to identify a product because the same product may be sold under different names. A two-part number is a primary registration. A three-part number is a supplemental distributor product with the same composition and efficacy as the primary product.

EPA also makes a point that is easy to miss. Each registered product lists the microorganisms it is effective against, and if a label has no directions for a particular pathogen, EPA has not reviewed data on whether the product is safe and effective that way. How to read the other parts of the label, and the safety data sheet behind it, is covered in reading cleaning product labels and safety data sheets.

EPA disinfectant lists, including List N

EPA maintains lettered lists of registered products for particular pathogens. Examples on its page include List G for norovirus, List N for SARS-CoV-2 and List S for bloodborne pathogens such as HIV, hepatitis B and hepatitis C. EPA states that inclusion on a list does not constitute an endorsement of one product over another, and that users must still read the label to confirm the product is approved for the intended use site or pest (EPA).

For workplaces, EPA notes that using a listed product consistent with its labelling complies with OSHA's requirements for occupational exposure to bloodborne pathogens.

Which job fits which setting

CDC's overview is reassuring about everyday life. In most situations, cleaning alone with soap and water can remove most germs, and disinfecting at home is likely not needed unless someone is sick or someone sick has recently visited. High-touch surfaces such as light switches, doorknobs and countertops should be cleaned regularly and after visitors, while other surfaces can be cleaned when visibly dirty. Disinfection is sensible when someone in the household is sick or is at higher risk of getting sick, for example because of a weakened immune system (CDC). A reasonable household rhythm built on those ideas is sketched in daily, weekly and deep-clean schedules for a home.

Sanitizing has its own narrow uses. CDC lists food contact surfaces after a natural disaster, the inside of a refrigerator after a recalled food item, and nonporous objects such as certain toys and infant feeding items.

In a shared workplace the same logic applies at larger scale: regular cleaning of high-touch points, with disinfection reserved for situations such as illness or a spill that calls for it. Facilities usually write this down in procedures, and the practical side is described in office hygiene and shared-surface cleaning.

Food surfaces and household bleach

Disinfecting and sanitizing are not interchangeable around food. The USDA Food Safety and Inspection Service says to use sanitizing products only if they are intended for cutting boards or utensils that touch food, and that disinfecting products, unlike some commercial sanitizers, should not be used on those items because they could contaminate the food. Disinfectants can be used on surfaces and high-touch areas. USDA describes a food-safe homemade sanitizer for boards and knives as one tablespoon of unscented liquid chlorine bleach in a gallon of water (USDA FSIS, Preventing Cross-Contamination).

When bleach is the disinfectant, CDC's separate bleach page says to use regular unscented household bleach containing 5% to 9% sodium hypochlorite, to follow the label, and, if the bottle gives no directions, to leave a solution of 5 tablespoons (one third cup) per gallon of room-temperature water on the surface for at least 1 minute while it stays visibly wet. It says to make a fresh solution daily, because a mixed solution loses effectiveness after about 24 hours, and never to mix bleach or any disinfectant with other cleaners or disinfectants (CDC, Cleaning and Disinfecting with Bleach). The reasons behind that last rule are set out in mixing cleaning chemicals safely.

The product label and, in a workplace, the employer's training come before any general summary like this one. CDC also cautions that some cleaning and disinfection products can trigger asthma, which is one more reason to ventilate and to wear the protective equipment named on the label.

The short version

Cleaning removes soil and most germs, sanitizing reduces germs to a safe level, and disinfecting kills more of them and is held to a higher regulatory standard. Clean first, follow the label's contact time, and reserve disinfecting for illness, higher-risk people or specific situations. For everything else, regular cleaning is usually enough.