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Chemical Hazard
Chemical hazards are Hazard, hazards present in Dangerous goods, hazardous chemicals and hazardous materials. Exposure to certain chemicals can cause Acute health hazard, acute or long-term adverse health effects. Chemical hazards are usually classified separately from biological hazards (biohazards). Chemical hazards are classified into groups that include Asphyxiant gas, asphyxiants, Corrosive substance, corrosives, Irritant (biology), irritants, sensitization (immunology), sensitizers, carcinogens, mutagens, teratogens, reactants, and Combustibility and flammability, flammables. In the workplace, exposure to chemical hazards is a type of occupational hazard. The use of personal protective equipment may substantially reduce the risk of adverse health effects from contact with hazardous materials. Long-term exposure to chemical hazards such as Silicon dioxide, silica dust, Exhaust gas, engine exhausts, tobacco smoke, and lead (among others) have been shown to increase risk of Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazard
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific ''incident'', combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech. Hazards can be classified in several ways which are not mutually exclusive. They can be classified by ''causing actor'' (for example, natural or anthropogenic), by ''physical nature'' (e.g. biological or chemical) or by ''type of damage'' (e.g., health hazard or environmental hazard). Examples of natural disasters with highly harmful impacts on a society are floods, droughts, earthquakes, tropical cyclones, lightning strikes, volcanic activity and wildfires. Technological and anthropogenic hazards include, for example, structural collapses, transport accidents, acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Smoke
Tobacco smoke is a sooty aerosol produced by the incomplete combustion of tobacco during the smoking of cigarettes and other tobacco products. Temperatures in burning cigarettes range from about 400 °C between puffs to about 900 °C during a puff. During the burning of the cigarette tobacco (itself a complex mixture), thousands of chemical substances are generated by combustion, distillation, pyrolysis and pyrosynthesis. Tobacco smoke is used as a fumigant and inhalant. Composition The particles in tobacco smoke are liquid aerosol droplets (about 20% water), with a mass median aerodynamic diameter (MMAD) that is submicrometer (and thus, fairly "lung-respirable" by humans). The droplets are present in high concentrations (some estimates are as high as 1010 droplets per cm3). Tobacco smoke may be grouped into a particulate phase (trapped on a glass-fiber pad, and termed "TPM" (total particulate matter)) and a gas/vapor phase (which passes through such a glass-f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidizing Agent
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized". Common oxidizing agents are oxygen, hydrogen peroxide, and the halogens. In one sense, an oxidizing agent is a chemical species that undergoes a chemical reaction in which it gains one or more electrons. In that sense, it is one component in an oxidation–reduction (redox) reaction. In the second sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzoyl Peroxide
Benzoyl peroxide is a chemical compound (specifically, an organic peroxide) with structural formula , often abbreviated as (BzO)2. In terms of its structure, the molecule can be described as two benzoyl (, Bz) groups connected by a peroxide (). It is a white granular solid with a faint odour of benzaldehyde, poorly soluble in water but soluble in acetone, ethanol, and many other organic solvents. Benzoyl peroxide is an oxidizer, which is principally used in the production of polymers. Benzoyl peroxide is mainly used in production of plastics and for bleaching flour, hair, plastics and textiles. As a bleach, it has been used as a medication and a water disinfectant. As a medication, benzoyl peroxide is mostly used to treat acne, either alone or in combination with other treatments. Some versions are sold mixed with antibiotics such as clindamycin. It is on the World Health Organization's List of Essential Medicines. It is available as an over-the-counter and generic med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Ethyl Ketone Peroxide
Methyl ethyl ketone peroxide (MEKP) is an organic peroxide with the formula CH3)(C2H5)C(O2H)sub>2O2. MEKP is a colorless oily liquid. It is widely used in vulcanization (crosslinking) of polymers. It is derived from the reaction of methyl ethyl ketone and hydrogen peroxide under acidic conditions. Several products result from this reaction including a cyclic dimer. The linear dimer, the topic of this article, is the most prevalent. and this is the form that is typically quoted in the commercially available material. Solutions of 30 to 40% MEKP are used in industry and by hobbyists as catalyst to initiate the crosslinking of unsaturated polyester resins used in fiberglass, and casting. For this application, MEKP often is dissolved in a phlegmatizer such as dimethyl phthalate, cyclohexane peroxide, or to reduce sensitivity to shock. Benzoyl peroxide can be used for the same purpose. Safety Whereas acetone peroxide is a white powder at STP STP may refer to: Places * São ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Peroxides
In organic chemistry, organic peroxides are organic compounds containing the peroxide functional group (). If the R′ is hydrogen, the compounds are called hydroperoxides, which are discussed in that article. The O−O bond of peroxides easily breaks, producing free radicals of the form (the dot represents an unpaired electron). Thus, organic peroxides are useful as radical initiator, initiators for some types of polymerization, such as the Acrylic resin, acrylic, unsaturated polyester, and vinyl ester resins used in glass-reinforced plastics. methyl ethyl ketone peroxide, MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can explosively combust. Organic peroxides, like their inorganic counterparts, are often powerful bleaching agents. Types of organic peroxides Organic peroxides are classified (i) by the presence or absence of a hydroxyl () terminus and (ii) by the presence of alkyl vs acyl substituents. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be: * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or boiling liquid expanding vapor explosion * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane
Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum refining, it is often a constituent of liquefied petroleum gas (LPG), which is commonly used as a fuel in domestic and industrial applications and in low-emissions public transportation; other constituents of LPG may include propene, propylene, butane, butene, butylene, butadiene, and isobutylene. Discovered in 1857 by the French chemist Marcellin Berthelot, it became commercially available in the US by 1911. Propane has lower volumetric energy density than gasoline or coal, but has higher gravimetric energy density than them and burns more cleanly. Propane gas has become a popular choice for barbecues and portable stoves because its low −42 °C boiling point makes it vaporise inside pressurised liquid containers (it exists in two pha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottled Gas
Bottled gas is a term used for substances which are gaseous at standard temperature and pressure (STP) and have been compressed and stored in carbon steel, stainless steel, aluminum, or composite containers known as gas cylinders. Gas state in cylinders There are four cases: either the substance remains a gas at standard temperature but increased pressure, the substance liquefies at standard temperature but increased pressure, the substance is dissolved in a solvent, or the substance is liquefied at reduced temperature and increased pressure. In the last case the bottle is constructed with an inner and outer shell separated by a vacuum (dewar flask) so that the low temperature can be maintained by evaporative cooling. Case I The substance remains a ''gas'' at ''standard temperature'' and ''increased pressure'', its critical temperature being below standard temperature. Examples include: * air * argon * fluorine * helium * hydrogen * krypton * nitrogen * oxygen Case II The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Fuel
Diesel fuel, also called diesel oil, heavy oil (historically) or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and then injection of fuel. Therefore, diesel fuel needs good compression ignition characteristics. The most common type of diesel fuel is a specific fractional distillation, fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is sometimes called petrodiesel in some academic circles. Diesel is a high-volume product of oil refineries. In many countries, diesel fuel is standardized. For example, in the European Union, the standard for diesel fuel is EN 590. Ultra-low-sulfur diesel (ULSD) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammable Liquid
A flammable liquid is a liquid which can be easily ignited in air at ambient temperatures, i.e. it has a flash point at or below nominal threshold temperatures defined by a number of national and international standards organisations. The Occupational Safety and Health Administration (OSHA) of the United States Department of Labor defines a liquid as flammable if it has a flash point at or below 93 °C/199.4 °F. Prior to bringing regulations in line with the United Nations Globally Harmonized System of Classification and Labeling of Chemicals (GHS) in 2012, OSHA considered flammable liquids to be those with a flash point below 37.8 °C/100 °F. Those with flash points above 37.8 °C/100 °F and below 93.3 °C/200 °F were classified as combustible liquids. Studies show that the actual measure of a liquid's flammability, its flash point, is dependent on the local air pressure, meaning that at higher altitudes where the air pressure is lowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertension
Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide. High blood pressure is classified as essential hypertension, primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to non-specific lifestyle and Genetics, genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, overweight, excess body weight, smoking, physical inactivity and Alcohol (drug), alcohol use. The remaining 5–10% of cases are categorized as secondary hypertension, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
