Home » Biocides » Glossary

Effects of Biocides on antibiotic resistance


Glossary over Effects of Biocides

Active ingredient

The term “active ingredient” is mostly used in drugs to name the substance which is pharmaceutically active.

The term “active substance” is also used in biocidal products to name the component which actually kills, or otherwise controls pests or bacteria.

It is not necessarily the largest or most hazardous component of the product. Some products may contain more than one active ingredient or substance. Non-active ingredients are often called inert ingredients. (Source: GreenFacts)


An aerosol is a collection of microscopic particles, solid or liquid, suspended in a gas.

In the context of air pollution, an aerosol refers to fine particulate matter, that is larger than a molecule, but small enough to remain suspended in the atmosphere for at least several hours.

The term aerosol is also commonly used for a pressurized container (aerosol can) which is designed to release a fine spray of a material such as paint. It has also come to be associated, erroneously, with the gas (propellant) used to expel materials from an aerosol can. (Source: GreenFacts )



A class of natural or man-made substances, such as penicillin, that kill or inhibit the growth of some micro-organisms. (Source: GreenFacts, based on CoRIS, Glossary  )



An antimicrobial is a chemical substance which, at low concentrations, exerts an action against micro-organisms and destroys them or inhibits their growth.

Examples of antimicrobials targeting bacteria include antibiotics that act against infections in humans or animals and biocides such as disinfectants and preservatives. (Source: GreenFacts)


Bacteria are a major group of micro-organisms that live in soil, water, plants, organic matter, or the bodies of animals or people. They are microscopic and mostly unicellular, with a relatively simple cell structure.

Some bacteria cause diseases such as tetanus, typhoid fever, pneumonia, syphilis, cholera, and tuberculosis.

Bacteria play a role in the decomposition of organic matter and other chemical processes. (Source: GreenFacts)


Bacterial resistance

Bacterial resistance is the capacity of bacteria to withstand the effects of antibiotics or biocides that are intended to kill or control them. (Source: GreenFacts, based on the  SCENIHR opinion on Antibiotic Resistance Effects of Biocides )



According to the Biocides Directive (98/8/EC), biocidal products are those that are intended to destroy, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means. Examples include disinfectants, preservatives, antiseptics, pesticides, herbicides, fungicides and insecticides.

Biocidal products mentioned in the Biocides Directive are listed in the following table: (Source: GreenFacts, based on the Biocides Directive (98/8/EC)  )



Biofilms are communal structures of micro-organisms that adhere to living or inert surfaces and are encased in a protective coating secreted by them.

Bacteria living as a biofilm are able to resist to biocides and to antibiotics more effectively than those living as free organisms and they withstand considerably higher doses of antimicrobial products. (Source: GreenFacts)


The basic subunit of any living organism; the simplest unit that can exist as an independent living system. There are many different types of cells in complex organisms such as humans, each with specific characteristics. (Source: GreenFacts)


Cell membrane

The cell membrane is a fine structure that envelops a cell, separating the content of the cell from its surroundings.

It regulates the substances that can enter and leave the cell.

The membrane consists of a double layer of lipids in which proteins are embedded. (Source: GreenFacts)


The treatment of drinking water with a chloramine disinfectant. Both chlorine and small amounts of ammonia are added to the water one at a time which react together to form chloramine (also called combined chlorine), a long lasting disinfectant. As such, chloramine disinfection is sometimes used in large distribution systems. Chloraminated water is toxic to fish and must not be used for kidney dialysis. (Source: GreenFacts)



Chlorine (Cl2) is produced in large amounts and widely used both industrially and domestically as a disinfectant and bleach. In particular, it is widely used in the disinfection of swimming pools and is the most commonly used disinfectant and oxidant for drinking-water treatment. In water, chlorine reacts to form hypochlorous acid and hypochlorites. (Source: WHO  Guidelines for drinking water quality )

Confounding factor

A confounding factor in a study is a variable which is related to one or more of the variables defined in a study. A confounding factor may mask an actual association or falsely demonstrate an apparent association between the study variables where no real association between them exists. If confounding factors are not measured and considered, bias may result in the conclusion of the study. (Source: GreenFacts)


Cleaning product that usually contain surfactants to make oils and greases soluble in water and remove them more easily. (Source: GreenFacts)


DNA constitutes the molecules inside cells that carry genetic information and pass it from one generation to the next. (Source: NCI dictionary  )



A protein that encourages a biochemical reaction, usually speeding it up. Organisms could not function if they had no enzymes. (Source: NHGRI NHGRI Talking Glossary of Genetic Terms  )

Food web

The interconnected food chains (feeding relationships) in an ecosystem. Plants, herbivores, and carnivores all form parts of the food web. (Source: GreenFacts)


Gene expression

The process by which a gene is "turned on" to produce the specific biological molecule encoded by that gene (usually protein or RNA). (Source: GreenFacts )


The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein. (Source: NHGRI Talking Glossary of Genetic Terms  )

Genetic material

Any material of plant, animal, microbial or other origin that carries genetic information and that passes it from one generation to the next.

The information contained controls reproduction, development, behaviour, etc. (Source: GreenFacts )



The complete set of genes of an organism.

The human genome for instance contains 30 000 to 40 000 genes. (Source: GreenFacts)


Hand-rubs are sometimes referred to as waterless hand cleaners. They are often alcohol-base and work by killing germs that are present on the hands, contrarily to soap that does not kill germs but allows for the physical removal of germs when combined with running water and rubbing. (Source: ML Health Unit London Alcohol-based Hand Rubs  )

Heavy metals

Metallic elements with high atomic weights, e.g. mercury, chromium, cadmium, arsenic, and lead.

They can damage living things at low concentrations and tend to accumulate in the food chain. (Source: US EPA Drinking Water Glossary  )


It is the growth of a parasite within the human body that causes illness. It can be a virus, a bacteria, a fungus or a protozoa. (Source: GreenFacts )


A substance that kills insects. (Source: FAO Glossary of biotechnology & genetic engineering  )


An ion is an atom or molecule that is not electrically neutral, but instead carries a positive or negative electrical charge, which is due to the loss or gain of one or more electrons.

An anion is a ion with a negative electrical charge, e.g. chloride (CI-), as opposed to a cation which is an ion with a positive electrical charge, e.g. sodium (Na+). (Source: GreenFacts)


Legionella are large family of micro-organisms which are naturally found in water bodies and sometimes soil.

Legionella attach to surfaces forming a biofilm.

They have been shown to colonise hot water tanks and various materials found in water systems including plastics, rubber, and wood when water temperatures are between 40 and 50° C.

Many species of Legionella give rise to diseases in humans. (Source: GreenFacts, based on the Legionella experts   )



The conversion or breakdown of a substance from one form to another by an enzyme. (Source: GreenFacts, based on ATSDR Glossary of Terms )



Any living organism that is too small to be seen by the naked eye such as bacteria, viruses, protozoa, single-celled algae, and many types of fungi. (Source: GreenFacts)


A molecule is the smallest part of any chemical compound composed of two or more atoms and which has the qualities of that substance and can exist alone in a free state. As an example, a molecule of water (H2O) consists of two atoms of hydrogen and one of oxygen. (Source: GreenFacts, based on Helios Glossary   )


Parasitic, microscopic fungi (like Penicillin) with spores that float in the air like pollen. Mold is a common trigger for allergies and can be found in damp areas, such as the basement or bathroom, as well as in the outdoor environment in grass, leaf piles, hay, mulch or under mushrooms. (Source: WebMD Asthma Glossary of Terms  )

Mucous membrane

The moist layer of tissue lining the digestive, respiratory, urinary and reproductive tracts - all the body cavities with openings to the outside world except the ears. (Source: Medical dictionary   )


Any permanent change in the DNA of a cell.

Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment.

Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited.

Certain mutations may lead to cancer or other diseases. (Source: NCI dictionary   )


The approximately 20 chemical elements known to be essential for the growth of living organisms, including nitrogen, sulfur, phosphorus, and carbon. (Source: Millennium Ecosystem Assessment Glossary   )



Ozone is a form of oxygen having the molecular form of O3. It is a bluish, unstable gas with a pungent odour, found in two parts of the atmosphere: the stratosphere and the troposphere.

The ozone layer: The stratosphere contains a layer in which the concentration of ozone is greatest, the so called ozone layer. The layer extends from about 12 to 40 km. It shields the Earth from ultraviolet radiation's harmful health effects on humans and the environment. This layer is being depleted by human emissions of chlorine- and bromine-containing compounds.

Ground-level ozone: At ground level (in the troposphere), ozone is considered an air pollutant that can seriously affect the human respiratory system. It is a chemical oxidant and a major component of photochemical smog. (Source: GreenFacts)



A toxic chemical product that kills harmful organisms (e.g., insecticides, fungicide, weedicides, rodenticides, acaricides). (Source: FAO Glossary of biotechnology & genetic engineering  )



Study of the biological, chemical and physical activities and processes that underlie the functioning of living organisms (cells, tissues, organs, and organ systems) and their parts. (Source: GreenFacts)


A large molecule composed of one or more chains of amino acids in a specific order, formed according to genetic information.


Quaternary ammonium cation

Quaternary ammonium cations are positively charged ions with the structure NR4+ with N being a nitrogen atom and R being alkyl groups consisting of carbon and hydrogen atoms arranged in a chain. They are permanently charged, independently of the acidity of their solution.

Quaternary ammonium salts, also referred to as quaternary ammonium compounds or “quats”, are salts of quaternary ammonium cations combined with a negatively charged anion. They are used as disinfectants, surfactants, fabric softeners, and as antistatic agents (e.g. in shampoo). (Source: GreenFacts)

Risk assessment

A scientifically based process consisting of four steps:

  • hazard identification,
  • hazard characterization,
  • exposure assessment and
  • risk characterization
(Source:   Official Journal of the European Communities 2002 L 31 )


Scientific Committee on Emerging and Newly Identified Health Risks

The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) was set up in 2004 by the European Commission to provide the Commission with unambiguous scientific advice on the safety of a series of issues requiring a comprehensive assessment of the risks, such as new technologies, medical devices, etc.

The SCENIHR advice is intended to enable risk managers to take the adequate and required actions in order to guarantee consumer safety or public health.

The SCENIHR addresses questions concerning emerging or newly-identified risks and on broad, complex or multi-disciplinary issues requiring a comprehensive assessment of risks to consumer safety or public health and related issues not covered by other Community risk- assessment bodies.

The Scientific Committee on Emerging and Newly Identified Health Risks is composed of a maximum of 13 members, but for any specific question may enlist the support of up to six associated members selected on the basis of their expertise. There is also a reserve list made up of candidates found suitable for a position in a Scientific Committee but not appointed. The members of the SCENIHR are appointed on the basis of their skills and experience in the fields in question, and consistent with this a geographical distribution that reflects the diversity of scientific problems and approaches in the European Union (EU). The experts' term of office is three years and is renewable for a maximum of three consecutive times. In agreement with the Commission, the Scientific Committees may turn to specialised external experts.

The SCENIHR complies with the principles of independence, transparency and confidentiality. The members therefore make a declaration of commitment to act in the public interest and a declaration of interests; requests for opinions, agendas, minutes and opinions are published; work and publications are done with regard to the need for commercial confidentiality. (Source: SCENIHR pages  )

Scientific Committee on Health and Environmental Risks

The Scientific Committee on Health and Environmental Risks (SCHER) is one of three independent non-food scientific committees that advise the European Commission on matters of consumer safety, public health and the environment.

The committee was set up in 2004 to provide the European Commission with scientific advice on health and environmental risks. It replaced the Scientific Committee on Toxicity, Ecotoxicity and the Environment (CSTEE).

SCHER addresses questions relating to examinations of the toxicity and ecotoxicity of chemicals, biochemicals and biological compound whose use may have harmful consequences for human health and the environment.

In particular, the Committee addresses questions related to new and existing chemicals, the restriction and marketing of dangerous substances, biocides, waste, environmental contaminants, plastic and other materials used for water pipe work (e.g. new organics substances), drinking water, indoor and ambient air quality. It addresses questions relating to human exposure to mixtures of chemicals, sensitisation and identification of endocrine disrupters.

The SCHER complies with the principles of independence, transparency and confidentiality. SCHER members therefore make a declaration of commitment to act in the public interest and a declaration of interests; requests for opinions, agendas, minutes and opinions are published; work and publications are done with regard to the need for commercial confidentiality.

For further information on the SCHER see:
SCHER website 


Sewage refers to waste-water from homes and industry which is collected and carried away in sewers (pipes or tunnels). When raw waste-water is cleaned in treatment plants the waste product is sewage sludge, which can be used as a fertiliser under certain conditions or deposited in landfills. (Source: GreenFacts )


A group of organisms that differ from all other groups of organisms and that are capable of breeding and producing fertile offspring. This is the smallest unit of classification for plants and animals. (Source: OceanLink Glossary of Common Terms and Definitions in Marine Biology  )



A surfactant is a substance that reduces the surface tension of a liquid in which it is dissolved.

When dissolved in water a surfactant gives a product the ability to remove dirt from surfaces such as the human skin, textiles, and other solids. (Source: GreenFacts)


A group of cells joined to perform a set of functions. (Source: GreenFacts)

Tolerance to biocides

Bacteria develop “tolerance” if they become less affected by a biocide so that higher concentrations of the biocide are needed to stop them multiplying. (Source: GreenFacts)


Able to poison or harm an organism. Toxic substances can cause adverse health effects. (Source: GreenFacts)


Triclosan is an organic compound with a slight phenolic smell.

Triclosan is commonly used as disinfectant or antiseptic to reduce and control bacterial contamination.

Because of its antibacterial properties it is included in many detergents, soaps, deodorants, toothpastes, cosmetics, shaving creams, mouth washes, and cleaning supplies, but also in consumer products, such as kitchen utensils, toys, bedding, socks, and trash bags. (Source: GreenFacts)


A virus is a small organism which can infect other biological organisms.

Viruses can only reproduce by invading and taking over cells as they lack the cellular machinery for self reproduction.

They cause diseases in human beings, animals, plants and bacteria.

Examples of human diseases caused by viruses include the common cold, influenza, small pox, AIDS, and cold sores. (Source: GreenFacts)


Other articles you might like...
Acrylamide in food home
Is there a risk to health?
Aluminium exposure home
Does aluminium pose a health risk?
Pesticides occupational risks home
We review the scientific literature regarding the health risks associated with occupational exposure to pesticides.
A-Z List
    Themes covered
    Publications A-Z