VOC is the abbreviation of volatile organic compounds. VOC in the ordinary sense refers to volatile organic compounds; but the definition of environmental protection refers to a kind of active volatile organic compounds, that is, the kind of volatile organic compounds that cause harm.
The VOC can also represent VOC files: Creative's waveform audio file format, which is also the audio file format used by the sound blaster. Each VOC file consists of a header block and an audio block. The header contains an identification version number and a pointer to the beginning of the data block. Data blocks are divided into various types of sub-blocks. For example, the sound data mute identifies the ASCII code file with duplicate result repeats and termination flags, extension blocks, and the like.
For example, the US ASTM D3960-98 standard defines VOC as any organic compound that can participate in atmospheric photochemical reactions. Definition of the US Federal Environmental Protection Agency (EPA): Volatile organic compounds are any carbon compounds that participate in atmospheric photochemical reactions in addition to CO, CO2, H2CO3, metal carbides, metal carbonates, and ammonium carbonate.
The World Health Organization (WHO, 1989) defines total volatile organic compounds (TVOCs) as a general term for volatile organic compounds having a melting point below room temperature and a boiling point between 50 and 260 °C.
The international standard ISO 4618/1-1998 for general terms for paints and varnishes and the German DIN 55649-2000 standard define VOCs as, in principle, any organic liquid and/or solid that can self-expose at normal temperature and pressure. . At the same time, the German DIN 55649-2000 standard defines a VOC content, that is, any organic compound whose boiling point or initial boiling point is lower than or equal to 250 ° C under normal pressure conditions.
According to BASF, the most convenient and common method is to define which substances belong to VOCs based on boiling points, and the most common consensus is that VOCs are those whose boiling point is equal to or lower than 250 °C. Therefore, those substances with a boiling point exceeding 250 ° C are not classified as VOCs and are often referred to as plasticizers.
These definitions have the same, but each has its own focus.
As defined by the United States, the initial boiling point of the boiling point is not limited, emphasizing participation in atmospheric photochemical reactions. Those who do not participate in atmospheric photochemical reactions are called exempt solvents such as acetone and tetrachloroethane. The World Health Organization and BASF limit the boiling point or initial boiling point, regardless of whether they participate in atmospheric photochemical reactions. The international standard ISO 4618/1-1998 and the German DIN 55649-2000 standard do not limit the boiling point of the initial boiling point, and whether or not they participate in atmospheric photochemical reactions, only emphasize that they can self-produce under normal temperature and pressure.
The definition of these VOCs can be divided into two categories.
One type is a VOC definition in the ordinary sense, which only states what is a volatile organic compound or under what conditions it is a volatile organic compound;
The other type is the definition of environmental protection, that is to say, the kind of volatile organic compounds that are active, that is, the kind of volatile organic compounds that cause harm. It is very obvious that in terms of environmental protection, it is very important to volatilize and participate in atmospheric photochemical reactions. It does not pose a hazard if it does not volatilize or does not participate in atmospheric photochemical reactions. This is why Europe classifies solvents as potential for photochemical ozone generation.
harm
VOC, a volatile organic compound, has a huge impact on human health. When the VOC in the living room reaches a certain concentration, people will feel headache, nausea, vomiting, fatigue, etc. in a short time. In severe cases, convulsions and coma will occur, and the liver, kidney, brain and nervous system will be damaged, resulting in memory. Serious consequences such as decline.
The paint used in the home decoration process is one of the main sources of indoor VOC. Therefore, countries have restricted the VOC content in decorative materials such as paints.
The relevant provisions
The VOC content defined in the national standard GB6582-2001 Interior Decoration Materials for Interior Paints, which was enforced from July 1, is: "The total volatile matter content in the paint deducts the moisture content, which is the paint. Volatile organic compound content. "In general, the less VOC contained in a material, the less harmful it is to the human body. The requirements for VOC content in interior wall coatings in paint national standards are: no more than 200 grams per liter.
Foreign developed countries have strict restrictions on VOC content in paints. In the case of the European Union, one type of (matte) coatings shall not exceed 30 grams per liter, and the second category (light class) shall not exceed 200 grams per liter; while in China, the State Environmental Protection Administration releases the latest waterborne interior wall coatings. The environmental labeling product certification requirements stipulate that the VOC shall not exceed 100 grams per liter; the “Safety and Quality Evaluation Rules for Interior Decoration Coatings†formulated by Beijing Municipality shall have a VOC requirement of 125 grams per liter or less.
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