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background concentration

an average or expected concentration of a substance l in a specific environment, or typical concentrations of substances that occur naturally in an environment.

background contamination in air

an average or expected imission in the environment of an air polluting source.

bacterial gene expression regulation

bacteria usually control gene expression by regulating the level of mRNA transcription. In bacteria, genes with related function are generally located adjacent to each other and they are regulated co-ordinately . Coordinate regulation of clustered genes is accomplished by regulating the production of a polycistronic mRNA (a large mRNA containing the information for several genes). Thus, bacteria are able to "sense" their environment and express the appropriate set of genes needed for that environment by regulating transcription of those genes.


Bactericides are substances that kill bacteria. Bactericides are either disinfectants, antiseptics or antibiotics. Bactericides are widely used in human and animal therapy, in agriculture plant pesticides and in different industries for killing harmful bacteria.

bacteristatic agents

bacterostatic agent or shotly bacteriostat is a biological or chemical agent that stops bacteria from reproducing, while not necessarily harming them otherwise.

Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics and preservatives can be distinguished. Upon removal of the bacteriostat, the bacteria usually start to grow again. This is in contrast to bactericides, which kill bacteria.


BioAccumulation Factor is the ratio between concentration in an organism or in a part or organ of an organism, and exposure level, = environmental concentration. It is also called Bioconcentration Factor, BCF.


unit of pressure. Normal atmospheric pressure 1 atmosphere = 1.013 bar (= 1013 mbar).


a barrel is a hollow cylindrical container, traditionally made of vertical wooden staves and bound by wooden or metal hoops.

Barrel is also one of several units of volume, with dry barrels, fluid barrels (UK beer barrel, U.S. beer barrel), oil barrel, etc. The conversion to other units of volume:

barrels, US beergallons31
barrels, US beerliters117.347 77
barrels, US petroleumgallons (British)34.97
barrels, US petroleumgallons (US)42
barrels, US petroleumliters158.987 29
barrels, US proof spiritsgallons40
barrels, US proof spiritsliters151.416 47
base noise
base rock
base-catalysed dechlorination
Basel Convention

adopted in 1989 and entered into force on 5 May 1992. The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal aims to minimise the generation of hazardous wastes and control their movement.

basic research
basis air pollution

Best Available Techniques Not Entailing Excessive Cost.


An electrical battery consists of one or more electrochemical cells, which are able to convert the chemical energy stored in the battery into electrical energy. The cell was developed by Alessandro Volta, in 1800. Today, the battery is a common power source for households, industries and toys.

Batteries may be used once and discarded, or recharged for years as in standby power applications. Miniature cells are used to power devices such as wristwatches and portable electronic devices; larger batteries provide standby power for telephone exchanges or computer data centers, for cars and other vehicles, incuding electric cars.

The 2006/66/EC European Directive (see the Summary of EU waste Legislation on Batteries and Accumulators) aims at minimising the negative impacts of batteries and accumulators on the environment. The Directive introduces measures to prohibit the marketing of some batteries containing hazardous substances. The Directive contains measures for establishing schemes aiming at high level of collection and recycling of batteries with quantified collection and recycling targets.

battery-electric vehicles (BEV)

BEVs store electricity in batteries and draw power from the batteries to run an electric motor that drives the vehicle. So long as the ultimat electricity source is clean, the BEV system can reduce emissions significantly compared with an internal combustion engine vehicle (ICEV) run on a liquid fuel. Indeed, BEVs using WWS power would be completely zero-emission vehicles. Moreover, BEVs get about 5 times more work (in miles of travel) per unit of input energy than do ICEVs (mi/kWh-outlet versus mi/kWh-gasoline). BEVs have existed for decades in small levels of production, and today most major automobile companies are developing BEVs. The latest generation of vehicles uses lithium-ion batteries, which do not use the toxic chemicals associated with lead-acid or the nickel-cadmium batteries (1).

Vehicles using both electric motors and internal combustion engines are examples of hybrid electric vehicles, and are not considered pure (or all) EVs because they operate in a charge-sustaining mode.

  • Regular hybrid electric vehicles cannot be externally charged.
  • Hybrid vehicles with batteries that can be charged externally to displace some or all of their internal combustion engine power and gasoline fuel are called plug-in hybrid electric vehicles (PHEV), and are BEVs during their charge-depleting mode.

All-electric and plug-in hybrids are off-vehicle charge capable. (“OVCC” or pluginable), which means their batteries can be charged from an off-vehicle electric energy source that cannot be connected or coupled to the vehicle while the vehicle is being driven (2)


(1) Mark Z. Jacobson and Mark A. Delucchi: Evaluating the Feasibility of a Large-Scale Wind, Water, and Sun Energy Infrastructure

(2) http://en.wikipedia.org/wiki/Battery_electric_vehicle

benchmark dose (BMD

the BMD concept involves fitting a mathematical model to dose-response data. The BMD is defined as the dose causing a predetermined change in response.

Source: REACH

Benchmark Dose (BMD), REACH

the BMD concept involves fitting a mathematical model to dose-response data. The BMD is defined as the dose causing a predetermined change in response.
The BMD10 Benchmark-dose associated with a 10% response (for tumours upon lifetime exposure after correction for spontaneous incidence, for other effects in a specified study.
The BMDL10 is the lower 95% confidence interval of a Benchmark-dose representing a 10% response (e.g., tumour response upon lifetime exposure), i.e. the lower 95% confidence interval of a BMD10. (Source: REACH Glossary)


benthos is the community of organisms which live in the bed sediment of freshwater or the sea, in the so called benthic zone.

The size of living organisms may vary largely, some of them are microorganisms, not or hardfly visible by naked eyes, these constitute microbenthos. The bigger ones belong to the mezo or macrobenthos.

Benthic community of freshwater and the sea are significantly different.

Light does not penetrate very deep waters, that is why the energy source for deep benthic ecosystems is often organic matter from higher up in the water column which drifts down to the depths. This dead and decaying matter sustains the benthic food chain; most organisms in the benthic zone are scavengers or detritivores.

See also zoobenthos.

bentic community

community of sediment dwelling organisms, named also benthos.


a colorless liquid with a sweet odor. It belongs to hydrocarbons, the simplest representative of aromatics with chemical formula of C6H6. Its boiling temperature is 80,5 °C, melting temperature 6 °C, specific gravity 0.880 g/cm3 at 20 °C. It evaporates into the air very quickly and dissolves slightly in water. It is highly flammable and is formed from both natural processes and human activities. Natural sources of benzene include emissions from volcanoes and forest fires. benzene is also a natural part of crude oil, gasoline, and cigarette smoke.benzene is widely used to make other chemicals which are applied to make plastics, resins, and nylon and other synthetic fibers. benzene is also used to make some types of rubbers, lubricants, dyes, detergents, drugs, and pesticides. It breaks down slowly in water and soil, and can pass through the soil into underground water. benzene does not build up in plants or animals. Breathing very high levels of benzene can result in death, while high levels can cause drowsiness, dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness. Eating or drinking foods containing high levels of benzene can cause vomiting, irritation of the stomach, dizziness, sleepiness, convulsions, rapid heart rate, and death. The major effect of benzene from long-term exposure is on the blood. benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection. Long-term exposure to high levels of benzene in the air can cause leukemia, particularly acute myelogenous leukemia, often referred to as AML. This is a cancer of the bloodforming organs. The Department of Health and Human Services (DHHS) in the USA has determined that benzene is a known carcinogen. The International Agency for Research on Cancer (IARC) and the EPA have determined that benzene is carcinogenic to humans. (Source: Agency for Toxic Substances and Deseas Registry, ATSDR, www.atsdr.cdc.gov)

benzene and

benzene, or benzol, is an aromatic ring with the molecular formula C6H6. benzene is a colorless and flammable liquid with a strong smell and a relatively high melting point. Because it is a known carcinogen, its use as in gasoline is now limited, but it is an important industrialsolvent and precursor in the production of drugs and plastics. benzene is a natural constituent of mineral oil.

Alkylbenzenes are organic compounds that has an alkyl group bound to a benzene ring. Two well known alkylbenzenes are methylbenzene and toluene, both are colorless flammable liquids obtained from petroleum or coal tar, used as a solvent for gums and lacquers and in high-octane fuels. See also BTEX.


Best Environmental Practices (BEPs), the application of the most appropriate combination of environmental control measures or strategies in order to reduce the impact of specific substances or applications.

Best Available Technology
Best Available Technology BAT
Best Practicable Environmental Option
Best Practicable Environmental Option BPEO

the Best Practicable Environmental Option BPEO Twelfth Report, FEB 1988, Cm 310, is a set of procedures adopted by Great Britain with the goal of managing waste and other environmental concerns. According to the Royal Commission on Environmental Pollution, BPEO "emphasises the protection and conservation of the environment across land, air and water. The BPEO procedure establishes for a given set of objectives, the option that provides the most benefits or the least damage to the environment, as a whole, at acceptable cost, in the long term as well as in the short term."
Source: Wikipedia, http://en.wikipedia.org/wiki/Best_practicable_environmental_option

best practice

one thousand million (in the U.S.). 1,000,000,000=109.


a microbial, plant or animal species whose presence, abundance, and health reveal the general condition of its habitat. The specific chemical, biochemical or genetical characteristic or molecule of these species can also function and bio-indicator. These bio-indicators can be used as measured endpoints in ecological surveys or ecotoxicological test methods.

bioaccumulative substance

Bioaccumulative and very bioaccumulative substances are those, which are able to concentrate in the body of living organisms of microbial cells, plants or animals, including man. Bioconcentration is measured related to the environment and is quantitatively characterized by the BCF = bioconcentration factos, which is the ratio of two concentrations, the concentration in the organism or organ and the concentration in the environmental compartment.

BCF Plant = Cplant/ Csoil, or BCF Fish is Cfish/Cwater. Bioaccumulation of certain substances, e.g. hydrofobic organic substances in liver of adipose tissue or inorganic substances such as toxic metals Pb, Cd, or mercury in plant shoot and leaves leads to the toxication of the food-chain and biomagnification along the food-chain.

According to REACH regulation a substance fulfils the bioaccumulative criterion when:
– the bioconcentration factor (BCF) is higher than 2 000.
The assessment of bioaccumulation - according to REACH methodology - shall be based on measured data on bioconcentration in aquatic species. Data from freshwater as well as marine water species can be used. This kind of aquatic bioconcentration of the substances serves as basis to declare a substance PBT (Bioaccumulative, Persistent and Toxic), which is a priority risk category of REACH.

biochemical indicators
Biocides Directive 98/8/EC

Directive 98/8/EC of the European Parliament and of the Council on the placing on the market of biocidal products was adopted in 1998. According to the Directive, Member States had to transpose the rules before 14 May 2000 into national law.

The Commission adopted the original proposal for the Directive in 1993. Directive 91/414/EEC on plant protection products, adopted in 1991, served as a model for the new Directive.

The Biocidal Product Directive aims to harmonise the European market for biocidal products and their active substances. At the same time it aims to provide a high level of protection for humans, animals and the environment.

biocides, REACH

biocides are defined in Article 2 (1) of the Biocidal Products Directive (98/8/EC) as:
"Active substances and preparations containing one or more active substances, put up in the form in which they are supplied to the user, intended to destroy, deter, render harmless, prevent the action of, or otherwise exert a controlling effect on any harmful organism by chemical or biological means."
Note, however, that many substances or preparations which meet this definition are excluded from the Biocidal Products Directive on the basis of being covered by other legislation such as the Plant Protection Products Directive (91/414/EEC) and many other Directives relating to veterinary medicines, proprietary medicinal products etc. Therefore, for a complete definition of a biocidal products you should consult the Biocidal Products Directive and its associated guidance.
In general terms, the scope of the Biocidal Products Directive is very wide, covering 23 different product types. This includes disinfectants for home and industrial use, preservatives for manufactured and natural products, non-agricultural pesticides for use against insects, rodents and other vertebrates and specialised products such as embalming/taxidermist fluids and antifouling products. A full list of product types is in Annex V of the BPD.
Under Article 15 (2) of the REACH Regulation, active substances which are regulated as biocides are regarded as being already registered under REACH.
Directive 98/8/EC, Articles 1 and 2.; REACH Article 15 (2).

Bioconcentration Factor
BioConcentration Factor BCF

a bioconcentration+Factor" target="_blank">bioconcentration Factor L/kg can either be expressed as the ratio of the concentration of a substance in an organism to the concentration in water once a steady state has been achieved static BCF, or, on a non-equillibrium basis, as the quotient of the uptake and depuration rate constants dynamic BCF. Static and dynamic BCFs can be equally used for regulatory purposes. The parameter gives an indication of the accumulation potential of a substance. Source: REACH Glossary

biodegradable polimers
biodegradable waste

biodegradable waste is any waste that is capable of undergoing anaerobic or aerobic decomposition, such as food and garden waste, and paper and paperboard

Source: Council Directive 1999/31/EC of 26 April 1999 on the landfill of waste. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31999L0031:EN:HTML


decomposition or breakdown of a substance through the action of microorganisms, such as bacteria or fungi.