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one of the petroleum hydrocarbons, 2,2",4-trimethyl-pentane, colorless liquid, used together with isooctane for determination of the octane number of gasoline.

nanoscale materials can be grouped into three categories: natural, incidental, and engineered.

Examples of naturally occurring nanoscale materials include clays, organic matter, and iron oxides within soil that play an important role in biogeochemical processes (Klaine et al. 2008).

Incidental nanoscale materials enter the environment through atmospheric emissions, solid or liquid waste streams from nanoscale material production facilities, agricultural operations, fuel combustion, and weathering (Klaine et al. 2008; U.S. EPA 2008).

Engineered or manufactured nanoscale materials are designed with specific properties and may be released into the environment through industrial or environmental applications. Nanoscale materials may be produced via a "top down" approach, such as by milling or grinding macroscale materials or, most commonly, via a "bottom up" approach, such as borohydride reduction, which creates nanoscale materials from component atoms or molecules (Lien et al. 2006; U.S. EPA 2007).

Several terms are used to describe nanoscale materials, including nanoparticles, nanoscale particles, nanomaterials, nanosized particles, nanosized materials, nano-objects, and nanostructured materials. This website uses the term "nanoscale materials." This term also includes materials that may be microscale or macroscale in size with an active component that is nanoscale in range.

Nanoscale materials are being used in a variety of applications within the scientific, environmental, industrial, and medical arenas. The list below includes examples of nanoscale materials, as well as their properties and uses:

* Nanoscale materials that may exist naturally or may be engineered:

  • Fullerenes and carbon nanotubes exist as hollow spheres (buckyballs), ellipsoids, or tubes (nanotubes), which are composed entirely of carbon. They are strong antioxidants, are stable, have limited reactivity, and have excellent thermal and electrical conductivity. Their use includes biomedical, super-capacitor, sensor, and photovoltaic applications (U.S. EPA 2009).
  • Nanosized metal oxides include titanium dioxide (TiO2), zinc oxide (ZnO), cerium oxide (CeO2), and iron oxide (Fe3O4), some of which are able to block ultraviolet light. They consist of closely packed semiconductor crystals, which are composed of hundreds or thousands of atoms. Uses of metal oxides include applications in photocatalysts, pigments, drugs (to control release), medical diagnostics, and sunscreen (U.S. EPA 2009).

* Nanoscale materials that are engineered:

  • Zero-valent metals, such as nanoscale zero-valent iron (nZVI), have high surface reactivity and are used in the remediation of water, sediments, and soils. See Nanoscale Materials for more information.
  • Quantum dots are semiconductors whose excitons (bound electron-hole pairs) are confined in all three spatial dimensions. They range in size from 10 to 50 nanometers. Quantum dot applications include medical imaging, photovoltaics, telecommunications, and sensors.
  • Dendrimers are highly branched polymers that can be designed and manufactured to incorporate a variety of functional groups. Common shapes include cones, spheres, and disc-like structures. Dendrimers are used in drug delivery, chemical sensors, modified electrodes, and as DNA transferring agents.
  • Composite nanoscale materials are made from two or more different nanoscale materials or one nanoscale material that is combined with bulk type materials. Composite nanoscale materials may be integrated with biological and synthetic molecules, which provide novel electrical, catalytic, magnetic, mechanical, thermal, or imaging capabilities. Potential applications include drug delivery and cancer detection. They are used in auto parts and packaging materials to enhance mechanical and flame-retardant properties.

Klaine, S.J., P.J.J. Alvarez, G.E. Batley, T.E. Fernandes, R.D. Handy, D.Y. Lyon, S. Mahendra, M.J. McLaughlin, and J.R. Lead. 2008. Nanoparticles in the Environment: Behavior, Fate, Bioavailability, and Effects. Environmental Toxicology and Chemistry. 27(9):1825-1851.

Lien H-l., D.W. Elliott, Y-P. San, and W-X. Zhang. 2006. Recent Progress in Zero-Valent Iron Nanoparticles for Groundwater Remediation. Journal of Environmental Engineering and Management. 16(6):371-380.

U.S. Department of Health and Human Services (U.S. DHHS). Centers for Disease Control and Prevention. 2006. Approaches to Safe Nanotechnology: An Information Exchange with NIOSH. Available at: http://www.cdc.gov/niosh/topics/nanotech/safenano/.

U.S. Environmental Protection Agency (U.S. EPA). 2008. Nanotechnology for Site Remediation Fact Sheet. Solid Waste and Emergency Response. EPA 542-F-08-009. October 2008. Available at: http://www.clu-in.org/download/remed/542-f-08-009.pdfAdobe PDF Logo.

U.S. EPA. Science Policy Council. 2007. Nanotechnology White Paper. U.S. Environmental Protection Agency. February 2007. Available at: http://www.epa.gov/ncer/nano/publications/whitepaper12022005.pdfAdobe PDF Logo.

U.S. EPA. 2009. Emerging Contaminants - Nanomaterials Fact Sheet. Solid Waste and Emergency Response. EPA 505-F-09-011. September 2009. Available at: http://www.clu-in.org/download/contaminantfocus/epa505f09011.pdfAdobe PDF Logo.

nano-materials in environmental remediation

an increasing variety of nanoscale materials with environmental applications has been developed over the past several years. For example, nanoscale materials have been used to remediate contaminated soil and groundwater at hazardous waste sites, such as sites contaminated by chlorinated solvents or oil spills. As indicated above, many types of nanoscale materials are being applied across various fields of science and technology; this website focuses on the use of engineered nanoscale materials for environmental site remediation. Nanoscale materials are of interest for environmental applications because the surface areas of the particles are large when compared with their volumes; therefore, their reactivity in chemical or biological surface mediated reactions can be greatly enhanced in comparison to the same material at much larger sizes (U.S. EPA 2007). They can be manipulated for specific applications to create novel properties not present in particles of the same material at the micro- or macroscale. Nanoscale materials can be highly reactive in part because of the large surface area to volume ratio and the presence of a larger number of reactive sites; but may also exhibit altered reaction rates that surface-area alone cannot account for. These properties allow for increased contact with contaminants, thereby resulting in rapid reduction of contaminant concentrations. Furthermore, because of their minute size, nanoscale materials may pervade very small spaces in the subsurface and remain suspended in groundwater if appropriate coatings are used. Appropriate coating may allow the particles to travel farther than macro-sized particles, achieve wider distribution, and therefore improve contaminant reduction.

Some applications of nanoscale materials for environmental remediation are in the research phase but others are rapidly progressing from pilot-scale to full-scale implementation. For example, certain nanoscale materials hold promise for environmental applications in addressing challenging sites, such as sites contaminated with chlorinated solvents. Ongoing bench- and pilot-scale research is being performed to investigate particles such as TiO2, self-assembled monolayers on mesoporous supports (SAMMSTM), dendrimers, carbon nanotubes, metalloporphyrinogens, and swellable organically modified silica (SOMS). This research is evaluating how to apply the unique chemical and physical properties of these nanoscale materials for use in full-scale environmental remediation (see the Nanotechnology Products with Potential Remediation Applications section). In addition, there are many unanswered questions about nanotechnology. For example, more research is needed to understand the fate and transport of free nanoscale materials in the environment, whether they are persistent, whether they have toxicological effects on various biological systems, and whether the theoretical benefits of nanoscale materials can be realized in broad commercial use (U.S. EPA 2008). Furthermore, nanoscale materials are also being considered for use in sensing and monitoring environmental contaminants; however, research and development of nanosensors are still in progress (U.S. EPA 2007).

U.S. Environmental Protection Agency (U.S. EPA). 2008. Nanotechnology for Site Remediation Fact Sheet. Solid Waste and Emergency Response. EPA 542-F-08-009. October 2008. Available at: http://www.clu-in.org/download/remed/542-f-08-009.pdfAdobe PDF Logo.

U.S. EPA. Science Policy Council. 2007. Nanotechnology White Paper. U.S. Environmental Protection Agency. February 2007. Available at: http://www.epa.gov/ncer/nano/publications/whitepaper12022005.pdfAdobe PDF Logo.

petroleum industry term for a cycloparaffin (cycloalkane).
National Institute for Chemical Safety (NICS)
Natura 2000 sites
natural area
Natural Attenuation (NA)

Natural Attenuation relies on natural processes to clean up or attenuate pollution in soil and groundwater. Natural attenuation occurs at most polluted sites. However, the right conditions must exist underground to clean sites properly. If not, cleanup will not be quick enough or complete enough. Scientists monitor or test these conditions to make sure natural attenuation is working. This is called monitored natural attenuation or MNA.

When the environment is polluted with chemicals, nature can work in four ways to clean it up:

1. Tiny bugs or microbes that live in soil and groundwater use some chemicals for food. When they completely digest the chemicals, they can change them into water and harmless gases.

2. Chemicals can stick or sorb to soil, which holds them in place. This does not clean up the chemicals, but it can keep them from polluting groundwater and leaving the site.

3. As pollution moves through soil and groundwater, it can mix with clean water. This reduces or dilutes the pollution.

4. Some chemicals, like oil and solvents, can evaporate, which means they change from liquids to gases within the soil. If these gases escape to the air at the ground surface, sunlight may destroy them.

MNA works best where the source of pollution has been removed. For instance, buried waste must be dug up and disposed of properly. Or it can be removed using other available cleanup methods. After the source is removed, the natural processes get rid of the small amount of pollution that remains in the soil and groundwater. The soil and groundwater are monitored regularly to make sure they are cleaned up.

Source: US-EPA, Clu-In: http://www.clu-in.org/techfocus/default.focus/sec/Natural_Attenuation/cat/Overview/

Natural Attenuation as basis of soil remediation
natural attenuation of organic pollutants in soil
natural condition
natural resource
natural value
natural waste-water treatment
naturally occuring substances, REACH
substances which occur in nature means a naturally occurring substance as such, unprocessed or processed only by manual, mechanical or gravitational means, by dissolution in water, by flotation, by extraction with water, by steam distillation or by heating solely to remove water, or which is extracted from air by any means. (Source: REACH Glossary)
nature and biodiversity conservation

ecologists, naturalists, and other scientists collectively research and address issues pertaining to global declines in biodiversity. The conservation ethic advocates management of natural resources for the purpose of sustaining biodiversity in species, ecosystems, the evolutionary process, and human culture and society.

Conservation biology is reforming around strategic plans that include principles, guidelines, and tools for the purpose of protecting biodiversity. Conservation biology is crisis–oriented and multi–disciplinary, including ecology, social organization, education, and other disciplines outside of biology.

Preserving biodiversity is a global priority in strategic conservation plans that are designed to engage public policy and concerns affecting local, regional and global scales of communities, ecosystems, and cultures.

Action plans identify ways of sustaining human well-being, employing natural capital, market capital, and ecosystem services.

near infrared NIR
near natural condition
NEP, N-ethyl-2-pyrrolidone

A series of new pyrrolidon products aim to substitute problematic solvents in chemical industries and consumer uses:

N-Cyclohexyl pyrrolidone
N-Ethyl pyrrolidone
N-Hydroxyethyl pyrrolidone
N-Octyl pyrrolidone.

N-ethylpyrrolidone (NEP) can be used as a pharmaceutical building block and can also be used as solvent in low temperature applications.

Characteriastion of NEP by http://www.nhpvp.com/N-ETHYLPYRROLIDONE.html:

CAS NO.:2687-91-4
  Molecular weight :113.1 g/mol
  Density at 25℃: 0.993 g/ml
  Boiling Point: 212℃
  Melting Point: -77℃
Formula:C6H11NO  Viscosity at 25℃: 3.5 mPa.s

Appearance  Clear, colorless liquid
APHA  50 max. (Pt-Co Color) 
Assay  99.6% min. (by gas chromatography)
γ-Butyrolactone  0.1% max. (by gas chromatography)
Amines  0.1% max. (by gas chromatography)
Water  0.1% max.

N-ethylpyrrolidone (NEP) is the lactam of 4-ethylaminobutyric acid and a very weak base. NEP is a chemically stable and powerful polar solvent. These characteristics are highly useful in a variety of chemical reactions where an inert medium is of concern. Despite the stability of NEP, it can also play an active role in certain reactions: hydrolysis, oxidation, condensation, conversion with chlorinating agents, polymerization and o-alkylation, and related reactions.

Low impurity level applications:
· lithium ion batteries· wafer degreasing
· photoresist stripper· coating developer
· epoxy deflashing

200 kgs plastic drum.

Care should be used when handling NEP. Skin contact should be avoided. Contact,can resultin irritation; prolonged contact can result in redness and dermatitis. Butylrubber or FEPTeflon gloves are recommended when handlingNEP. A good skincream should be used afterwashing the affected area. As with all solvents, theworkplace should be well ventilated andsafety goggles must be worn.
NEP has an almost unlimited shelf life in sealed containers when properly stored in a protected storage area in original unopened containers or protected from moisture. It is neither explosive nor spontaneously flammable in air. However, it is combustible. When ignited, NEP will sustain a fire. All types of fire extinguishers are effective against NEP fires.

The classification and labeling of NEP is and ongoing issue in Europe, under REACH and CLP Regulations.


neurotoxicology is the study of the adverse effects of chemical, biological, and certain physical agents on the nervous system and/or behavior during development and in maturity. Many common substances are neurotoxic, including lead, mercury, some pesticides, and ethanol.

Neurotoxicity testing is used to identify potential neurotoxic substances. Neurotoxicity is a major toxicity endpoint that must be evaluated for many regulatory applications. Sometimes neurotoxicity testing is considered as a component of target organ toxicity; the central nervous system (CNS) being one of the major target organ systems. In utero exposure to chemicals and drugs can also exert an adverse effect on the development of the nervous system, which is called developmental neurotoxicity (DNT).

Like other target organ toxicities, neurotoxicity can result from different types of exposure to a substance; the major routes of exposure are oral, dermal, or inhalation. Neurotoxicity may be observed after a single (acute) dose or after repeated (chronic) dosing.

Source: http://alttox.org/ttrc/toxicity-tests/neurotoxicity/

new chemicals
nfrared technology in IT
nanogram, metric unit of mass, a decimal unit of mass based on the gram
1 microgram = 1000 nanogram
1 nanogram = one billionth (1/1,000,000,000) gram
Nickel (Ni)
NICOLE Network

Network for Industrially Contaminated Land in Europe.
NICOLE (Network for Contaminated Land in Europe) was set up in 1995 as a result of the CEFIC “SUSTECH” programme which promotes co-operation between industry and academia on the development of sustainable technologies. NICOLE is the principal forum that European business uses to develop and influence the state of the art in contaminated land management in Europe. NICOLE was created to bring together problem holders and researchers throughout Europe WHO are interested in all aspects of contaminated land. It is open to public and private sector organisations. NICOLE
was initiated as a Concerted Action within the European Commission’s Environment and Climate RTD Programme in 1996. It has been self-funding since February 1999.
NICOLE’s overall objectives are to:
1) Provide a European forum for the dissemination and exchange of knowledge and ideas about contaminated land
arising from industrial and commercial activities; 
2) Identify research needs and promote collaborative research that will enable European industry to identify,
assess and manage contaminated sites more efficiently and cost-effectively; and
3) Collaborate with other international networks inside and outside Europe and encompass the views of a wide range of interest groups and stakeholders (for example, land developers, local/regional authorities and the insurance/financial investment community).
NICOLE currently has 156 members. Membership fees are used to support and further the aims of the network, including: technical exchanges, network conferences, special interest meetings, brokerage of research and research contacts and information dissemination via a web site, newsletter and journal publications. (Source: http://www.nicole.org)

nitroaromatics, EUGRIS

nitroaromatics are carcinogenic and mutagenic aromatic substances, that are typical contaminants of contaminated military sites, e.g. 2,4,6-Trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT), 1,3,5-trinitro-1,3,5-triazine (also known as RDX), cyclotetramethylene tetranitramine (also known as HMX), some pesticides (atrazine), and a number of anilines. (Source: EUGRIS)


nitrobenzene is a water-insoluble pale yellow oil with an almond-like odor. It is produced on a large scale as a precursor to aniline. Although occasionally used as a flavoring or perfume additive, nitrobenzene is highly toxic in large quantities. In the laboratory, it is occasionally used as a solvent.

Nitrobenzene is highly toxic, mainly for blood cells and kidney, as well as for the brain. It is readily absorbed through the lung and

The summary of the UK Health Protection Agency says:

Fire hazard:

  • Flammable
  • Violently reacts with strong oxidants, acids and nitrogen oxides
  • Emits toxic fumes of nitrogen oxides when heated to decomposition
  • In the event of a fire involving nitrobenzene, use fine water and liquid tight chemical protective clothing with breathing apparatus

Health hazard:

  • Toxic by inhalation, ingestion and skin absorption
  • Possibly carcinogenic in humans
  • May cause reproductive toxicity
  • The onset of symptoms may be delayed 1-4 hours after exposure to nitrobenzene
  • Inhalation can cause irritation of the respiratory tract, nausea, headache, dizziness, shortness of breath and in extreme cases could lead to coma and death
  • Ingestion of nitrobenzene may cause gastrointestinal irritation with nausea, vomiting and diarrhoea, as well as symptoms similar to those for inhalation
  • Inhalation and ingestion may also cause vertigo and bluish colouration of the skin due to a condition called methaemoglobinaemia, with drowsiness, high blood pressure, convulsions, anaemia, jaundice and kidney failure
  • Skin contact with nitrobenzene may result in mild skin irritation and eye contact may lead to mild eye irritation

Environmental hazard::

  • Dangerous for the environment
  • Inform Environment Agency of substantial incidents

Prolonged exposure may cause serious damage to the central nervous system, impair vision, cause liver or kidney damage, anemia and lung irritation. Inhalation of fumes may induce headache, nausea, fatigue, dizziness, cyanosis, weakness in the arms and legs, and in rare cases may be fatal. The oil is readily absorbed through the skin and may increase heart rate, cause convulsions or rarely death. Ingestion may similarly cause headaches, dizziness, nausea, vomiting and gastrointestinal irritation, loss of limbs and also causes internal bleeding.

Nitrobenzene is considered a likely human carcinogen by the United States Environmental Protection Agency too.

Sources and further information:





nitrogen is a chemical element that has the symbol N, its atomic number is 7, its atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere.

Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen dominates nitrogen chemistry, causing difficulty for both organisms and industry in breaking the bond to convert the N2 into useful compounds, but releasing large amounts of often useful energy, when these compounds burn, explode, or decay back into nitrogen gas.

Nitrogen is a biogenic element, it occurs in all living organisms. It is a constituent element of amino acids and thus of proteins, and of nucleic acids (DNA and RNA). It resides in the chemical structure of almost all neurotransmitters, and is a defining component of alkaloids, biological molecules produced by many organisms.

The global nitrogen cycle is linked to all environmental compartments: atmosphere, waters and soils. Elemental nitrogen in the atmosphere cannot be used directly by either plants or animals, specific soil bacteria are able to fix atmospheric nitrogen in the form of ammonium and used by themselves (Azotobacter) or supplied for symbiotic plants, e.g. by Rhyzobium. Plants are able to utilise nitrates (NO3), the result of mineralisation of organic compounds by microorganisms. Many bacteria living in soils and waters biodegrade dead organic material, when organically bound nitrogen is converted into ammonia (ammonification). Nitro- and nitrosobacteria are able to oxidise ammonia into nitrite or nitrate (nitrification). Facultative anaerobic bacteria are able to reduce nitrate in the process of denitrification (basis of many water and soil biotechnologies), using nitrate for their alternative respiration (nitrate respiration), producing nitrogen gas or ammonia. Microorganisms play essential role in nitrogen-cycle.

During the hystory of Earth, N derived from evaporation of the Earth crust or from chemical reactions. N-reserve of Earth can be be found in the atmospheric air: cca. 4x1012 tons N2.

nitrogen biogeochemical cycle
nitrogen dioxide
nitrogen monoxide

nanometre, basic unit of length, one billionth meter: 1 nanometre = 0, 000,000,001 metre, or 10-9 metre.
1 μm = 1000 nm.

The wavelength of visible light falls into the range of 400-700 nm.

no effect concentration
no effect dose
No Longer Polymer (NLP):
No Longer Polymers (NLP), REACH

A NLP is a substance which was considered as notified under Article 8 (1) of the 6th amendment of Directive 67/548/EEC (and hence did not have to be notified under that Directive), but which does not meet the REACH definition of a polymer (which is the same as the polymer definition introduced by the 7th amendment of Directive 67/548/EEC) (Source: REACH)

No Observed Adverse Effect Level (NOAEL)

highest dose with No Observable Adverse Effect. It is the highest tested dose or exposure level at which there are no statistically significant increases in the frequency or severity of adverse effects between exposed population and an appropriate control group. Some effects may be produced at this level, but they are not considered adverse ort precursors of adverse effects (Source: REACH).

No Observed Adverse Effects Concentration (NOAEC)
NOEC is the highest tested concentration at which there is no adverse effect on the testorganism, no statistically significant difference in the measured endpoint compared to untreated on long term.
No Observed Effects Concentration (NOEC)
no till farming

tillage is a general term that describes several processes used in the preparation of soil for planting crops. These activities can lead to unfavorable effects such as soil compaction, loss of organic matter, degradation of soil aggregates and a disruption of soil organisms. No-till farming (also called zero tillage) is a way of growing crops from year to year without disturbing the soil through ploughing the land which can increase the amount of water in the soil, decrease erosion and lead to an increase in the amount and variety of life in and on the soil.


National Oceanic and Atmospheric Administration, with whidespread activity on daily weather forecasts, severe storm warnings and climate monitoring, fisheries management, coastal restoration and supporting marine commerce.

NOAA’s dedicated scientists use cutting-edge research and high-tech instrumentation to provide citizens, planners, emergency managers and other decision makers with reliable information they need when they need it.

The Office of Satellite Data Processing and Distribution (OSDPD) collects, processes, and distributes environmental satellite data and derived products about Earth's weather, atmosphere, oceans, land, and near-space conditions to domestic and foreign users. The Office of Satellite Data Processing and Distribution (OSDPD) manages and directs the operation of the central ground facilities which ingest, process, and distribute environmental satellite data and derived products to domestic and foreign users. OSDPD maintains a continuous and reliable stream of satellite data and products. Satellite imagery and products are available on their website.


No Effect level, the highest dose, which does not show any affect on the testorganisms.


noise is sound which is unwanted, either because of its effects on humans, its effect on fatigue or malfunction of physical equipment, or its interference with the perception or detection of other sounds.

Types of noise:

  • aerodynamic noise
  • airborne noise
  • background noise
  • impulsive noise
  • intermittent noise
  • rolling noise
  • steady noise
  • structure-borne noise
noise background load
noise emission limit value
noise gauge instrument