Lexikon

pharmacology is the closest related branch of applied science to human toxicology, which is the study of drug action. The methodology is very similar to human toxicity assessment, the difference is, that drugs are applied for their beneficial effects on human or other organisms, and the main effect has a special target (e.g. to kill pathogens or harmful cells, etc.). More specifically, pharmacology is the study of the interactions that occur between a living organism and the chemicals substance, the drug, that affect biochemical function. If the substances have medicinal properties, they are considered pharmaceuticals and the assessment is pharmacological assessment. If the drug is a toxicant, toxicology is dealing with its effects. As all drugs, even if they have a dose range, which leads to medicinal application, they are toxicants, it also underlines that the methodologies are very closely related, mainly the aim differentiates pharmacology from toxicology.

policyclic aromatic hydrocarbon, CAS No. 85-01-8

phenols, sometimes called phenolics, are a class of chemical compounds consisting of an -OH group attached to anaromatic benzene ring. The simplest of the class is phenol (C₆H₅OH).

phenols have unique properties and are not classified as alcohols (since the hydroxyl group is not bonded to a saturated carbon atom). They have relatively high acidity.
Some phenols are germicidal and are used in formulating disinfectants. Others possess endocrine disrupting activity.
Some others are biological active molecules with positive health effects, such as flavonoids and tannins, capsaicine or salicilic acid.

the physical characteristics of an organism or the presence of a disease that may or may not be genetic.

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phthalates, or phthalate esters, are esters of phthalic acid and are mainly used as plasticizers (substances added to plastics to increase their flexibility, transparency, durability, and longevity). They are used primarily to soften polyvinyl chloride. Phthalates are being phased out of many products in the United States, Canada, and European Union over health concerns.

DEHP has been the main “general purpose” phthalate used over the last 50 years. It has had applications in a wide range of soft-PVC and non-PVC polymer materials, these being further processed in the production of a range of indoor and outdoor products, both for industrial/professional and consumer uses. In addition to polymer applications DEHP has also been used in adhesives, sealants (which are often applied to windows and doors for improved insulation), rubber, lacquers, paints and printing
inks. Therefore, DEHP can be found in building and construction materials (e.g. in flooring, roofing, industrial doors, wires, cables, hoses and profiles), in coated fabrics (such as artificial leather for bags and automotive applications, book covers and bindings, maps and folders), in medical devices (e.g. blood bags, dialysis equipment) as well as in a multitude of other products such as traffic cones, buoys, curtains for lorries and train compartments, tarpaulins, signs, flexible containers, disposable gloves or dipped tool handles, sports mats, swimming pool covers, shower curtains, napkins, stationery films, water beds, furniture, luggage or shoe soles. It has also been reported to be used in primary packaging of medicinal products and active pharmaceutical substances (EU, 2008; ECHA, 2009; www.dehp-facts.com).

In October 2008, the low phthalates DEHP, DBP and BBP were included in the REACH “Candidate List” and in April 2009 ECHA proposed them for inclusion in the REACH Authorisation List (Annex XIV). The inclusion in the Authorisation List was confirmed officially in February 2011, with a phase-out date of February 2015 for these low phthalates unless they Authorised through submission of a dossier by manufacturers or users. Another low phthalate, DIBP, was proposed by Germany in September 2009 and was included on the REACH “Candidate List” in January 2010. As expected, these low phthalates were included on the list due to their EU hazardous classification. The full list of substances is available here.

In the case of low phthalates DEHP, DBP and BBP, they will have to undergo Authorisation. The main DEHP producer has already declared that they intend to seek Authorisation to ensure the continued availability of DEHP in the future.

The inclusion of DEHP, DBP, BBP and DIBP on the “candidate list” means that any EU manufacturer or importer of an article containing more than 0.1% weight by weight (w/w) of these phthalates must notify ECHA as of June 2011, unless the articles manufacturer or importer can clearly demonstate that their use has already been registered. In addition the article manufacturer or importer must now provide information to the recipient of that article. As a minimum, recipients – meaning anyone in the supply chain from distributors and retailers to professional end-users - need to be told that the article contains one or more of the substances. Further down the supply chain, retailers also have an obligation to provide the same information to consumers, but only if a consumer requests it. A retailer has 45 days to provide the information.

Six phtalates (DEHP, BBP, DINP, DIDP and DNOP) are under consideration to be restricted in Europe (under REACH) on the initiative of Denmark, who prepared a restriction dossier for phtalates and submitted it to ECHa (European Chemicals Agency).

Denmark submitted a dossier in May 2011, which proposes the restriction of bis(2-ethylhexyl) phthalate (DEHP), benzyl butyl phthalate (BBP), dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) in articles that are for indoor use, or in articles that come into contact with skin or mucous membranes, on the grounds that they are classified as category 1B reprotoxins under the CLP Regulation (CW 21 May 2011(http://chemicalwatch.com/7262/danes-cite-combined-exposure-in-reach-phthalates-proposals).

High phthalates are not classified as PBT or vPvB substances. They do not fulfill the criteria to be considered Substances of Very High Concern (SVHC) and therefore are not included on the EU REACH Candidate List nor do they need Authorisation to be placed on the EU market.

Sources:

http://www.plasticisers.org/regulation/reach

http://reseau-environnement-sante.fr/wp-content/uploads/2011/06/Veille_phtalates_au_26-06-11.pdf

http://en.wikipedia.org/wiki/Phthalate

physical weathering is caused by the effects of changing temperature on rocks, causing the rock to break apart. The process is sometimes assisted by water.

There are two main types of physical weathering:

• Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
• Exfoliation occurs when minerals in the rocks are continuously heated and cooled in hot climates.
• On the effect of cristal-formation of salts or oxide formation of iron or other metals. Increased volume of these chemical componunds break the rock.
• Plnat root growth is able to break the rock too.

Physical weathering happens especially in places places where there is little soil and few plants grow, such as in mountain regions and hot deserts. Either through repeated melting and freezing of water (mountains and tundra) or through expansion and contraction of the surface layer of rocks that are baked by the sun (hot deserts).

hysico-chemical testing methods for chemical substances: COUNCIL REGULATION (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

(1) Pursuant to Regulation (EC) No 1907/2006, test methods are to be adopted at Community level for the purposes of tests on substances where such tests are required to generate information on intrinsic properties of substances.

(2) Council Directive 67/548/EEC of 27 June 1967 on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances laid down, in Annex V, methods for the determination of the physico-chemical properties, toxicity and ecotoxicity of substances and preparations. Annex V to Directive 67/548/EEC has been deleted by Directive 2006/121/EC of the European Parliament and of the Council with effect from 1 June 2008.

(3) The test methods contained in Annex V to Directive 67/ 548/EEC should be incorporated into this Regulation.

(4) This Regulation does not exclude the use of other test methods, provided that their use is in accordance with Article 13(3) of Regulation 1907/2006.

(5) The principles of replacement, reduction and refinement of the use of animals in procedures should be fully taken into account in the design of the test methods, in particular when appropriate validated methods become available to replace, reduce or refine animal testing.

(6) The provisions of this Regulation are in accordance with the opinion of the Committee established under Article 133 of Regulation (EC) No 1907/2006

Article 1: The test methods to be applied for the purposes of Regulation 1907/2006/EC are set out in the Annex to this Regulation.

Article 2: The Commission shall review, where appropriate, the test methods contained in this Regulation with a view to replacing, reducing or refining testing on vertebrate animals.

Article 3: All references to Annex V to Directive 67/548/EEC shall be construed as references to this Regulation.

Article 4: This Regulation shall enter into force on the day following its publication in the Official Journal of the European Union.

It shall apply from 1 June 2008.

LIST OF METHODS FOR THE DETERMINATION OF PHYSICO-CHEMICAL PROPERTIES OF CHEMICAL SUBSTANCES

A.1. Melting/freezing temperature
A.2. Boiling temperature
A.3. Relative density
A.4. Vapour pressure
A.5. Surface tension
A.6. Water solubility
A.8. Partition coefficient
A.9. Flash-point
A.10. Flammability (solids)
A.11. Flammability (gases)
A.12. Flammability (contact with water)
A.13. Pyrophoric properties of solids and liquids
A.14. Explosive properties
A.15. Auto-ignition temperature (liquids and gases)
A.16. Relative self-ignition temperature for solids
A.17. Oxidising properties (solids)
A.18. Number – average molecular weight and molecular weight distribution of Polymers
A.19. Low molecular weight content of polymers
A.20. Solution/extraction behaviour of polymers in water
A.21. Oxidising properties (liquids)

phytotechnology is broadly defined as the use of vegetation to address contaminants in soil, sediment, surface water, and groundwater. Cleanup objectives for phytotechnologies can be contaminant removal and destruction, control and containment, or both. Phytoremediation (i.e., contaminant removal and destruction) is a phytotechnology subset (ITRC 2009).

While phytotechnologies generally are applied in situ, ex situ applications (e.g., hydroponics systems) are possible. Typical organic contaminants, such as petroleum hydrocarbons, gas condensates, crude oil, chlorinated compounds, pesticides, and explosive compounds, can be addressed using plant-based methods. Phytotechnologies also can be applied to typical inorganic contaminants, such as heavy metals, metalloids, radioactive materials, and salts (ITRC 2009).

Six major plant mechanisms enable phytotechnologies to remove, destroy, transfer, stabilize, or contain contaminants:

1.Phytoextraction

Phytoextraction involves contaminant uptake by plant roots, with subsequent accumulation in plant tissue. Plants that accumulate contaminants may require periodic harvesting and proper disposal to avoid recontaminating the soil when the plants die or drop their leaves. Phytoextraction typically is used to address inorganic contaminants, such as metals, metalloids, and radionuclides. Organic contaminants are more likely to be transformed rather than accumulated within the plant tissue. Successful field applications of phytoextraction to take up metals have been limited; however, promising research is underway for using phytoextraction on mercury and persistent organic pollutants (USEPA 2006).

Pesticides classified as persistent organic pollutants resist biodegradation and can remain in the environment for decades. Scientists have identified plants that are capable of extracting chemicals, such as chlordane and 2,2-bis(p-chlorophenyl)1,1-dichloroethene (p,p'-DDE), and storing them in their roots, leaves, and fruits (USEPA 2006).

Plants used in phytoextraction (e.g., Indian mustard, Alpine pennycress, sunflowers, ferns, grasses) typically are effective only in the top one foot of soil because of their shallow root systems and generally slow growth. Researchers are working on genetic modifications that increase the survivability of plants that hyperaccumulate toxic contaminants (USEPA 2006).

2. Phytodegradation

Like phytoextraction, phytodegradation involves the uptake of contaminants; however, metabolic processes within the plant subsequently break down the contaminants. Phytodegradation also encompasses the breakdown of contaminants in the soil through the effects of enzymes and other compounds produced by plant tissues other than the roots (USEPA 2006).

Phytodegradation is applicable to organic contaminants. Their uptake is affected by their hydrophobicity, solubility, and polarity; moderately hydrophobic and polar compounds are more likely to be taken up after sorbing to plant roots. Chlorinated solvents, herbicides, insecticides, pentachlorophenol (PCP), polychlorinated biphenyls (PCBs), and munitions constituents have phytodegradation potential (USEPA 2006).

3. Phytovolatilization

Phytovolatilization is the uptake of a contaminant into a plant and its subsequent transpiration to the atmosphere, or the transformation or phytodegradation of the contaminant with subsequent transpiration of the transformation or degradation products to the atmosphere. Phytovolatilization generally is applied to groundwater but also can be applied to soluble soil contaminants (USEPA 2006).

Transformation or degradation of the contaminant within the plant can create a less toxic product that is transpired; however, degradation of some contaminants, like trichloroethene (TCE), may produce even more toxic products (e.g., vinyl chloride). Once in the atmosphere, these products may be degraded more effectively by sunlight (photodegradation) than they would be by the plant (phytodegradation), but the potential advantages and disadvantages of phytovolatilization must be assessed on a site-specific basis (USEPA 2006).

Phytovolatilization has been applied to both organic and inorganic (e.g., selenium, mercury, arsenic) contaminants, but it must be reiterated that simply volatilizing a contaminant may not be an acceptable alternative (USEPA 2006).

4.Rhizodegradation

The rhizosphere is the zone of soil influenced by plant roots. Essentially, rhizodegradation is "plant-assisted bioremediation" in that the root zone enhances microbial activity, thus increasing the breakdown of organic contaminants (such as petroleum hydrocarbons, PAHs, pesticides, BTEX, chlorinated solvents, PCP, PCBs, and surfactants) in the soil. The rhizosphere extends only about 1 mm from each root. The presence of plant roots moderates soil moisture and increases soil aeration, making conditions more favorable to bioremediation. The production of root exudates, such as sugars, amino acids, and other compounds, stimulates the population growth and activity of native microbes. Root exudates also may serve as food for the microbes, which can result in cometabolism of contaminants as degradation of exudates occurs. Because the microbes consume nutrients, the plants in a rhizodegradation plot often require additional fertilization (USEPA 2006).

Rhizodegradation actually breaks down contaminants; thus, plant harvesting and disposal is not necessary. In some instances, complete mineralization of the contaminant can occur. The success of this technique is site-specific, however, and laboratory microcosms may not reflect the microbial conditions encountered in the field. Petroleum hydrocarbons have been degraded successfully in the rhizosphere, but degradation of aged hydrocarbons has been shown to be more problematic (USEPA 2006).

5.Phytosequestration

Phytosequestration, also referred to as phytostabilization, is a mechanism that immobilizes contaminants, mainly metals, within the root zone, limiting their migration. Immobilization of contaminants can result from adsorption of metals to plant roots, formation of metal complexes, precipitation of metal ions (e.g., due to a change in pH), or a change to a less toxic redox state. Phytosequestration can occur when plants alter the chemical and microbial makeup of the soil (e.g., through the production of exudates or carbon dioxide), which impacts the fate and transport of the soil metals. (USEPA 2006) Although transport proteins within the plant facilitate the transfer of contaminants between cells, plant cells contain a compartment called the vacuole that acts, in part, as a storage and waste receptacle for the plant. The vacuoles of root cells can sequester contaminants, preventing further translocation to the xylem (ITRC 2009).

Because contaminants are retained in the soil, phytosequestration does not require plant harvesting and disposal; however, evaluation of the system is necessary to verify that translocation of contaminants into the plant tissue is not occurring. Due to the continuing presence of contaminants in the root zone, plant health must be monitored and maintained to ensure system integrity and prevent future release of contaminants. Phytosequestration also can be used to prevent migration of soil contaminants with wind and water erosion, soil dispersion, and leaching (USEPA 2006).

6. Phytohydraulics

Phytohydraulics is the ability of vegetation to evapotranspire sources of surface water and groundwater. Water interception capacity by the aboveground canopy and subsequent evapotranspiration through the root system can limit vertical migration of water from the surface downward. The horizontal migration of groundwater can be controlled or contained using deep-rooted species, such as prairie plants and trees, to intercept, take up, and transpire the water. Trees classified as phreatophytes are deep-rooted, high-transpiring, water-loving organisms that send their roots into regions of high moisture and can survive in conditions of temporary saturation. Typical phreatophytes include species such as cottonwoods, poplars, and willows (ITRC 2009).

Source: USEPA. 2006. In Situ Treatment Technologies for Contaminated Soil: Engineering Forum Issue Paper. EPA 542-F-06-013.

ITRC (Interstate Technology & Regulatory Council). 2009. Phytotechnology

Technical and Regulatory Guidance and Decision Trees, Revised. Phyto-3

polychlorinated biphenyls (PCBs) are a class of chlorinated organic compounds, with 1-10 chlorine atoms bound to the biphenyl skeleton, which is the condensate of two benzene rings. The general chemical formula of PCBs is: C₁₂H_10-xCl_x. 

PCBs were used as dielectric fluids in transformers and capacitors, coolants, lubricants, stabilizing additives in flexible PVC coatings of electrical wiring and electronic components, they were used as pesticide extenders, flame retardants, hydraulic fluids, adhesives, anti-dust agents, coating of copy papers, etc.

PCB production was banned in the 1970s due to the high toxicity, mutagenicity and reprotoxicity. They are able to accumulate in the food chain. They are classified as POPs, Persistent organic pollutants.

Under Directive 67/548/EEC these are standard phrases indicating the special risks arising from the dangers involved in using the substance or preparation. For example "Danger of very serious irreversible effects", "Limited evidence of a carcinogenic effect". When the current provisions are repealed and GHS enters into force, the R-phrases will be replaced by "hazard statements". (Source: REACH Glossary)

The concrete risk-phrases are enlisted in the entry of verbal characterisation of risk of chemicals

standard phrases relating to the safe use of dangerous chemical substance. For example "Keep container tightly closed" or "avoid contact with skin" or "do not empty into drains". When the current provisions are repealed and GHS enters into force, the S-phrases will be replaced by "precautionary statements". (Source: REACH Glossary).

The S-phrases are enlisted under the entry of "safety advice for the use of dangerous substances".

soils support a number of inorganic and organic chemical reactions. Many of these reactions are dependent on some particular soil chemical properties. One of the most important chemical properties influencing reactions in a soil is pH. Soil pH is primarily controlled by the concentration of free hydrogen ions in the soil matrix. Soils with a relatively large concentration of hydrogen ions tend to be acidic. Alkaline soils have a relatively low concentration of hydrogen ions. Hydrogen ions are made available to the soil matrix by the dissociation of water, by the activity of plant roots, and by many chemical weathering reactions.

Soil fertility is directly influenced by pH through the solubility of many nutrients. At a pH lower than 5.5, many nutrients become very soluble and are readily leached from the soil profile. At high pH, nutrients become insoluble and plants cannot readily extract them. Maximum soil fertility occurs in the range 6.0 to 7.2.

Determination of soil pH is a complicate matter: we have to add water to be able to measure the pH, with this we dilute the soil (and the hydrogen ions to be measured) and we initiate the dissolution of normally particulate solid matter, which may modify the pH (for example, limestone). The whole procedure is time dependent.

solar photovoltaics (PVs) are arrays of cells containing a material, such as silicon, that converts solar radiation into electricity. Today solar PVs are used in a wide range of applications, from residential rooftop power generation to medium-scale utility-level power generation.

The Concentrated Solar Power (CSP) systems use mirrors or reflective lenses to focus sunlight on a fluid to heat it to a high temperature. The heated fluid flows from the collector to a heat engine where a portion of the heat is converted to electricity. Some types of CSP allow the heat to be stored for many hours so that electricity can be produced at night.

a chromatographic technique used to prepare samples for subsequent analysis, an effective method to concentrate or isolate the non-volatile analytes. It is a kind of column chromatography. The extract is eluted through the column (cartridge) containing the preconditioned sorbent by applying vacuum. The substance of interest is retained on the column and all the interfering components are eluted or the interfering components are retained and the substance of interest is eluted. This sample preparation technique is suitable for any compounds. The low solvent need, no need of concentration by evaporation and in this way avoiding the concentration of the polluting components, cheap sorbents, saving time, no emulsion formation, enhanced selectivity and potential for automatization are the advantages of SPE over the traditional liquid/liquid extraction (LLE).

in chromatography, the porous solid or liquid phase through which an introduced sample passes. The different affinities the stationary phase has for a sample allow the components in the sample to be separated or resolved.

Earth's atmosphere can be divided into five main layers. These layers are mainly determined by whether temperature increases or decreases with altitude. From highest to lowest, these layers are:

The troposphere begins at the Earth surface and extends to between 7 km (23,000 ft) at the poles and 17 km (56,000 ft) at the equator, with some variation due to weather. The troposphere is mostly heated by transfer of energy from the surface, so on average the lowest part of the troposphere is warmest and temperature decreases with altitude. This promotes vertical mixing. The troposphere contains roughly 80% of the mass of the atmosphere. The tropopause is the boundary between the troposphere and stratosphere. The temperature decrease is 6,5 ^oC/km upwards.

The stratosphere extends from the tropopause to about 51 km (32 mi; 170,000 ft). Temperature increases with height, which restricts turbulence and mixing. The stratopause, which is the boundary between the stratosphere and mesosphere, typically is at 50 to 55 km (31 to 34 mi; 160,000 to 180,000 ft). The pressure here is 1/1000th sea level and the temperature between −50 and −90 ^oC. The ozone-layer in the stratosphere may reach 0 ^oC due to the absorption of Sun UV radiation.

The mesosphere extends from the stratopause to 80–85 km (50–53 mi; 260,000–280,000 ft). It is the layer where most meteors burn up upon entering the atmosphere. Temperature decreases with height in the mesosphere. The mesopause, the temperature minimum that marks the top of the mesosphere, is the coldest place on Earth and has an average temperature around −85 °C (−121.0 °F; 188.1 K). Due to the cold temperature of the mesophere, water vapor is frozen, forming ice clouds (or Noctilucent clouds). A type of lightning referred to as either sprites or ELVES, form many miles above thunderclouds in the trophosphere.

Temperature increases with height in the thermosphere from the mesopause up to the thermopause, then is constant with height. The temperature of this layer can rise to 1,500 °C (2,730 °F), though the gas molecules are so far apart that temperature in the usual sense is not well defined. The International Space Station orbits in this layer, between 320 and 380 km (200 and 240 mi). The top of the thermosphere is the bottom of the exosphere, called the exobase. Its height varies with solar activity and ranges from about 350–800 km (220–500 mi; 1,100,000–2,600,000 ft).

Exosphere is the outermost layer of Earth's atmosphere extends from the exobase upward. Here the particles are so far apart that they can travel hundreds of kilometres without colliding with one another. Since the particles rarely collide, the atmosphere no longer behaves like a fluid. These free-moving particles follow ballistic trajectories and may migrate into and out of the magnetosphere or the solar wind. The exosphere is mainly composed of hydrogen and helium.

main hazard of this compound, similar to other metal phosphides primarily originates from the effects caused by liberation of hydrogen phosphide (PH₃) gas.For this reason, studies performed with other metal phosphides or PH₃ itself served as basis for assessing Mg₃P₂ toxicity.

Volatile petroleum hydrocarbons, that is the GRO (Gasoline Range Organics) consists of hydrocarbons containing between 6 and 10 carbon atoms and includes aromatic compounds, alkanes, cycloalkanes and branched alkanes. Approximately 40% of the hydrocarbons in fresh petrol are monoaromatic compounds such as benzene, toluene and ethylbenzene (BTEX). GRO is usually measured by headspace analysis or by purge and trap method. The sum of GRO and DRO gives TPH.