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Perfluorobutanesulfonic Acid
Perfluorobutanesulfonic acid (PFBS) is a chemical compound having a four-carbon fluorocarbon chain and a sulfonic acid functional group. It is stable and unreactive because of the strength of carbon–fluorine bonds. It can occur in the form of a colorless liquid or a corrosive solid. Its conjugate base is perfluorobutanesulfonate (also called nonaflate) which functions as the hydrophobe in fluorosurfactants. Since June 2003, 3M has used PFBS as a replacement for the persistent, toxic, and bioaccumulative compound perfluorooctanesulfonic acid (PFOS) in its Scotchgard stain repellents. 3M markets surfactant with PFBS in two fluorosurfactants. Safety PFBS has a half-life of a little over one month in humans, much shorter than PFOS with 5.4 years. PFBS is persistent in the environment. Studies have not yet been specifically conducted to determine safety in humans. The ECHA decision adding PFBS and its salts to the REACH Regulation Candidate List of Substances of Very High Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely, non-exponential) decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, ''half-life period'', dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to ''half-life'' in the early 1950s. Rutherford applied the principle of a radioactive element's half-life in studies of age determination of rocks by measuring the decay period of radium to lead-206. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Events Related To Per- And Polyfluoroalkyl Substances (PFAS)
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events. Timelines can use any suitable scale representing time, suiting the subject and data; many use a linear scale, in which a unit of distance is equal to a set amount of time. This timescale is dependent on the events in the timeline. A timeline of evolution can be over millions of years, whereas a timeline for the day of the September 11 attacks can take place over minutes, and that of an explosion over milliseconds. While many timelines use a linear timescale—especially where very large or small timespans are relevant -- logarithmic timelines entail a logarithmic scale of time; some "hurry up and wait" chronologies are depicted with zoom lens metaphors. History Time and space, particularly the line, are intertwined concepts in human thought. The line is ubiquitous in clocks in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluorinated Alkylated Substances
Per- and polyfluoroalkyl substances (PFASs) are synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl moiety, –CnF2n+1–. More recently (2021) the Organisation for Economic Co-operation and Development (OECD) expanded the definition, stating that "PFASs are defined as fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom (without any H/Cl/Br/I atom attached to it), i.e. with a few noted exceptions, any chemical with at least a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–) is a PFAS." According to the OECD, at least 4,730 distinct PFASs are known with at least three perfluorinated carbon atoms. A United States Environmental Protection Agency (EPA) toxicity database, DSSTox, lists 14,735 PFASs, while PubChem lists approximately 6 million. A subgroup, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FBSA
Perfluorobutane sulfonamide, also known as FBSA or H-FBSA, is a perfluorinated surfactant. FBSA and its N-alkylated derivatives have been patented by 3M for use in acid etch solutions with low surface tension. According to the inventors, FBSA and its derivatives are expected to have a smaller tendency to accumulate in living organisms than their perfluorooctanyl analogs such as PFOS. Nevertheless, a 2015 study found FBSA in 32 out of 33 samples of Canadian fish. Spills In April 2019, 3M admitted in a letter to the EPA that the plant in Decatur, Alabama released FBSA and FBSEE into the Tennessee River, despite a 2009 EPA order prohibiting release to water. Supposedly, authorities had been aware of the contamination since 2014, but did not make it public. The same facility has been responsible for release of other per- and polyfluorinated alkylated substances, namely PFOS and PFOA, into the Tennessee River, prompting 3M to pay $35 million to a local water authority in orde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PFNA
Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also an environmental contaminant found in people and wildlife along with PFOS and PFOA. Chemistry and properties In acidic form it is a highly reactive strong acid. In its conjugate base form as a salt it is stable and commonly ion paired with ammonium. In the commercial product Surflon S-111 (CAS 72968-3-88) it is the primary compound present by weight. PFNA is used as surfactant for the production of the fluoropolymer polyvinylidene fluoride.Supporting Information (PDF). It is produced mainly in Japan by the of a linear |
PFOA
Perfluorooctanoic acid (PFOA; conjugate base perfluorooctanoate; also known colloquially as C8, for its 8 carbon chain structure) is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a material feedstock. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, ''n''-octyl "tail group" and a carboxylate "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic. The tail group is inert and does not interact strongly with polar or non-polar chemical moieties; the head group is reactive and interacts strongly with polar groups, specifically water. The "tail" is hydrophobic due to being non-polar and lipophobic because fluorocarbons are less susceptible to the London dispersion force than hydrocarbons. PFOA is one of many synthetic organofluorine compounds collectively known as per- an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the largest by area east of the Mississippi River.''i.e.'', including water that is part of state territory. Georgia is the largest state by land area alone east of the Mississippi and Michigan the second-largest. Its capital is Lansing, and its largest city is Detroit. Metro Detroit is among the nation's most populous and largest metropolitan economies. Its name derives from a gallicized variant of the original Ojibwe word (), meaning "large water" or "large lake". Michigan consists of two peninsulas. The Lower Peninsula resembles the shape of a mitten, and comprises a majority of the state's land area. The Upper Peninsula (often called "the U.P.") is separated from the Lower Peninsula by the Straits of Mackinac, a channel tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substance Of Very High Concern
A substance of very high concern (SVHC) is a chemical substance (or part of a group of chemical substances) concerning which it has been proposed that use within the European Union be subject to authorisation under the REACH Regulation. Indeed, listing of a substance as an SVHC by the European Chemicals Agency (ECHA) is the first step in the procedure for authorisation or restriction of use of a chemical. The first list of SVHCs was published on 28 October 2008 and the list has been updated many times to include new candidates. The most recent update occurred in January 2022 to include a total of 223 SVHC. Criteria The criteria are given in article 57 of the REACH Regulation. A substance ''may'' be proposed as an SVHC if it meets one or more of the following criteria: *it is carcinogenic; *it is mutagenic; *it is toxic for reproduction; *it is persistent, bioaccumulative and toxicAnnex XIII, REACH Regulation, at pp. 383–85. (PBT substances); *it is very persistent and very b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Registration, Evaluation, Authorisation And Restriction Of Chemicals
Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) is a European Union regulation dating from 18 December 2006. REACH addresses the production and use of chemical substances, and their potential impacts on both human health and the environment. Its 849 pages took seven years to pass, and it has been described as the most complex legislation in the Union's history and the most important in 20 years. It is the strictest law to date regulating chemical substances and will affect industries throughout the world. REACH entered into force on 1 June 2007, with a phased implementation over the next decade. The regulation also established the European Chemicals Agency, which manages the technical, scientific and administrative aspects of REACH. Overview When REACH is fully in force, it will require all companies manufacturing or importing chemical substances into the European Union in quantities of one tonne or more per year to register these substances with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfactant
Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsion#Emulsifiers , emulsifiers, foaming agents, or dispersants. The word "surfactant" is a Blend word, blend of ''surface-active agent'', coined . Agents that increase surface tension are "surface active" in the literal sense but are not called surfactants as their effect is opposite to the common meaning. A common example of surface tension increase is salting out: by adding an inorganic salt to an aqueous solution of a weakly polar substance, the substance will precipitate. The substance may itself be a surfactant – this is one of the reasons why many surfactants are ineffective in sea water. Composition and structure Surfactants are usually organic compounds that are amphiphilic, meaning each molecule contains both a hydrophilic "water-seeking" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
