A biological detergent is a laundry detergent

Laundry detergent

Laundry detergent, or washing powder, is a substance that is a type of detergent that is added for cleaning laundry. In common usage, "detergent" refers to mixtures of chemical compounds including alkylbenzenesulfonates, which are similar to soap but are less affected by "hard water." In most...

 that contains enzymes harvested from micro-organisms such as bacteria adapted to live in hot spring

Hot spring

A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...

s. The description is commonly used in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, where other washing detergents are described as "non-biological" (or bio and "non-bio"). Most manufacturers of biological detergents also produce non-biological ones.

Method of operation and effectiveness

Biological detergents clean in the same way as non-biological ones with additional effects from the enzymes, whose purpose is to break down protein, starches and fat in dirt and stains on clothing to be laundered, for example food stains, sweat and mud.
Tests by the Consumers Association in the UK published in their Which?

Which?

Which? is a product-testing and consumer campaigning charity with a magazine, website and various other services run by Which? Ltd ....

 magazine rated the cleaning performance of washing powders based on stain removal, whiteness, and colour fading. It was found that the performance of various makes of biological powders ranged from 58% to 81%, and non-biological powders scored from 41% to 70%. The enzymes in biological detergents enable effective cleaning at lower temperatures than required by normal detergents, but are denatured at higher temperatures—about 40 °C is recommended.

Controversy regarding allergic reactions

It has been said that some people may be allergic to the enzymes which can be transferred to the skin when wet clothes that have just been cleaned with biological detergents are touched. The enzymes then restart the breakdown reaction on the skin—particularly protease. A study by a manufacturer found that "The biological products did not produce more irritation than the non-biological products, confirming that the addition of enzymes to a detergent formulation does not result in an increase in the skin irritation caused byprofile of the detergent. A study by hospital dermatologists published in the British Journal of Dermatology

British Journal of Dermatology

The British Journal of Dermatology is a British monthly medical journal that focuses on the field of dermatology. It is published by Wiley-Blackwell for the British Association of Dermatologists and is edited by Tanya O. Bleiker. In 2009, it had an impact factor of 4.260 and an immediacy index of...

found that "ultimately, the balance of all the enzymes in laundry detergents are not a cause of either skin irritation or skin allergy ... the supposed adverse effects of enzymes on the skin seem to be a consequence of mythology".