Disinfectants Vs Detergents

Detergents are solutions designed to aid in cleaning. Detergents contain surfactants to increase the contact between the cleaning solution, the soil and the surface to be cleaned. They also contain ingredients to solubilise soil & prevent re-deposition of suspended soil. Detergents are not designed to kill or inactivate microorganisms, when the correct high quality clinical detergent is used appropriately all soils should be removed from instruments or surfaces. This is important prior to sterilization or disinfection because soils can protect microorganism from the sterilization process or deactivate disinfectants.


Disinfectants are solutions that kill or inactivate non-sporing micro-organisms.  Disinfectants should not be used as a cleaning agent unless the product is specifically formulated as a 2 in 1 Cleaner/Disinfectant.

When using disinfectants ensure that you:

  • Know the recommended contact time (read the directions)
  • Clean the surface first (to avoid inactivation of disinfectant)


Important Facts About The Performance of Disinfectants

Kill Time varies dramatically depending on:

1. Concentration of disinfectant

2. Type of active ingredient

3. Type of organism and

4. Level of contamination (Soils, particularly organic matter, can inactivate many disinfectants).

For example, QUATs require long contact times (>10-20 minutes) whereas Alcohol & Chlorine require the shortest times (<10 minutes, typically 1-2 minutes for bacteria). QUATs generally have a narrow range of activity, are effective against gram-positive bacteria but less active against gram-negative bacteria, fungi and viruses. Some advanced QUAT based disinfectants contain a blend of different active ingredients that give the disinfectant broad and rapid activity.

Chlorine (e.g. Hypochlorite) have a wide spectrum of activity, but are concentration sensitive (if the concentration is too low then disinfection is not effective). Chlorine is inactivated by proteins, is corrosive to metals, irritating to skin and bleach and damage some materials.

Alcohol has a wide spectrum of activity with a rapid kill rate. They are generally safe on most hard surfaces and are not corrosive, they are however flammable but less affected by proteins compared to QUATs  and Chlorine