Adsorbable Organic Halides (AOX) Tests

Adsorbable organic halides (AOX) are a measure of the organic halogen load in a sampling area, such as soil, water, or sewage effluent in a landfill. The procedure measures chlorine, bromine, and iodine as equivalent halogens, but does not measure fluorine levels in the sample.

AOX stands for adsorbable organic bonded halogens, expressed as chlorides and determined according to the relevant European standard method. These are substances adsorbed from water onto activated carbon and can be volatile substances such as trichloromethane (chloroform), chlorophenols and chlorobenzenes, or complex organic molecules such as dioxins and furans. Most AOXs are molecules containing chlorine.

AOX is a total parameter used primarily for the evaluation of water and sewage sludge in chemical analyses. For many years, it has been a standard parameter in the German list of standard methods for the examination of water, wastewater and sludge. The AOX determination method has been included in numerous standards worldwide. Along with the standards of the American Society for Testing and Materials (ASTM) and the Environmental Protection Agency (EPA), the most frequently used standard for determining adsorbable organic halides is the standard "ISO 9562 Water quality - Determination of adsorbable organically bound halogens (AOX)", which is based on a European standard and published by the International Organization for Standardization (ISO). Here, the total adsorption of halogen compounds on activated carbon is determined.

The sum parameter provides a summary of one or more groups of substances under certain analytical conditions but does not provide information about individual substances.

The total parameter AOX is of vital importance as it provides insights into the pollution of the environment with halogenated organic compounds. These compounds are potentially toxic and can have long-term effects on ecosystems and human health. Analytical determination of adsorbable organic halides helps to monitor the presence and concentration of these compounds, which is essential for compliance with environmental standards and evaluation of cleanup measures. By obtaining this specific group of chemicals, AOX analysis helps environmental authorities, industrial organizations and research institutes to better understand and manage the effects of anthropogenic activities on the natural environment.

Adsorbable organic bonded halogens are chemical compounds that contain one or more halogen atoms, such as chlorine, bromine, iodine or fluorine, in organic molecules. These halogen atoms are bonded to organic carbon chains, producing a large number of compounds used in various industries.

The chemical structure of organically bonded halogens confers a number of unique properties that can be both beneficial and potentially dangerous. Their persistence in the environment and tendency to bioaccumulate can cause long-term environmental problems. In addition, some organic halogens can be toxic and have detrimental effects on human and animal health, especially if present in high concentrations.

The origin of halogenated organic compounds is a complex combination of natural and anthropogenic influences that require extensive analysis and monitoring to understand and minimize potential environmental impacts. Halogenated organic compounds are produced by biological processes involving, among others, microorganisms, algae, and plants. An example is marine algae and some plants that synthesize bromine compounds as a defense against other organisms that consume them. Halogenated organic compounds can also be produced by geological processes such as the weathering of rocks or the natural release of halogens from the Earth's mantle.

Among the anthropogenic sources of organically bound halogens, human activities also contribute significantly to the release of halogenated organic compounds. Synthetic AOX compounds are known above all as harmful substances, such as dichlorodiphenyltrichloroethane, dioxins, polychlorinated biphenyls (PCBs) or chlorofluorocarbons. They can also enter water bodies, wastewater or air directly as agricultural chemicals or cleaning agents from industry or households. Furthermore, halogenated organic compounds accumulate in the environment due to the disposal of industrial waste and domestic wastewater, especially if this waste is not treated properly. The combustion of waste and fossil fuels also results in the release of halogenated organic compounds such as dioxins and polychlorinated biphenyls (PCBs).

Adsorbable organic halogen compounds (AOX) can be found in a large number of products and materials commonly used in everyday life. These materials and products include plastics, textiles, electronic devices, construction and insulation materials, and packaging materials. They may contain halogenated additives that may be released during production or use. For example, many plastics contain halogenated flame retardants, while textiles are often treated with halogenated chemicals to make them flame retardant or water repellent. Plastic housings and printed circuit boards for electronic devices, construction and insulation materials, and packaging materials may also contain halogenated compounds.

In this respect, AOX analysis is important for the identification and monitoring of organic halogen compounds. AOX analysis plays an important role in the identification and monitoring of halogen compounds in various environmental matrices and products. By determining the amount of adsorbable organic halogens, potential hazards for the environment and human health can be identified and assessed. This analysis makes it possible to measure the contamination of water, soil and various products with halogenated compounds and thus to monitor pollution and regulatory compliance.

Since halogenated organic compounds, such as organochlorine compounds, have adverse effects on the human body and are potentially carcinogenic, AOX analysis is an important tool for the assessment and control of environmental quality and is used as the basis for the development of risk reduction measures.

Verifying halogen-free status is a critical step across a variety of industries, particularly in electronics, construction, and packaging. Through AOX analysis, businesses can be confident that their products or materials are free of halogenated compounds that could potentially harm the environment or health. This is particularly important because some halogenated compounds, such as brominated flame retardants or chlorinated paraffins, are toxic and can be persistent.

Results of AOX analysis are usually stated in micrograms per liter (µg/L) for aqueous samples or in micrograms per kilogram (µg/kg) for solid samples and sludge.

Our organization has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. Among the numerous test, measurement, analysis and evaluation studies provided for businesses in various sectors, there are also testing services for adsorbable organic halides (AOX).