Toxicity and corrosiveness

HjS is undesirable because of its toxicity and corrosive properties. COj can cause corrosion in the presence of water, and N2 simply reduces the calorific value of the gas as it is inert. 

Because PTFE resins decompose slowly, they may be heated to a high temperature. The toxicity of the pyrolysis products warrants care where exposure of personnel is likely to occur (120). Above 230°C decomposition rates become measurable (0.0001% per hour). Small amounts of toxic perfiuoroisobutylene have been isolated at 400°C and above free fluorine has never been found. Above 690°C the decomposition products bum but do not support combustion if the heat is removed. Combustion products consist primarily of carbon dioxide, carbon tetrafluoride, and small quantities of toxic and corrosive hydrogen fluoride. The PTFE resins are nonflammable and do not propagate flame. 

Because oxahc acid is toxic and corrosive, neither its crystals nor its solutions should be discarded to the environment without proper treatment. 

The Shoe grouting system is considered nonhazardous and nonpolluting. Sodium silicate is essentially nontoxic. Formamide is toxic and corrosive, but does not present a serious hazard if normal safety precautions are followed. Shoe chemical grout materials are two to five times more expensive than Portland cement, depending on the sodium silicate to formamide concentration ratios. Installed costs are generally more similar to those for cement grouts. 

Boron trichlorides are highly reactive, toxic, and corrosive these ttihaUdes (BCl, BBr, BI ) react vigorously, even explosively, with water. High temperature decomposition of BX can yield toxic halogen-containing fumes. Safe handling, especially of BCl, has been reviewed (11,80). 

In addition to the inherent flame resistance, the polymers are also interesting because of the low smoke generation and low levels of toxic and corrosive emissions when exposed to fire. 

These materials are developed from the polyetherimides introduced by General Electric (see also Section 18.14.2). At the time of writing one grade, Ultem Siltem STM 1500, is being offered. It is of particular interest as a material for wire and cable insulation, as it not only has excellent flame resistance coupled with low smoke generation but also avoids possible toxic and corrosion hazards of halogenated polymers. This can be of importance where there are possible escape problems in the event of a fire, such as in tunnels, aircraft and marine (particularly submarine) vessels. 

Cyanogen bromide (Bromine cyanide) CNBr Extremely irritating and toxic vapours Contact with acids, acid fumes, water or steam can produce toxic and corrosive fumes Transparent crystals with a penetrating odour Melting point 52°C Boiling point 61 °C Vapour density 3.6 Water soluble... 

Fire Hazards - Flash Point Flammable solid Flammable limits in Air (%) Not pertinent Fire Extinguishing Agents Sand and carbon dioxide Fire Extinguishing Agents Not to be Used Water fecial Hazards of Combustion Products Products of combustion include sulfur dioxide and phosphorus pentoxide, which are irritating, toxic and corrosive Behavior in Fire Not pertinent Ignition Temperature (deg. F) 527 (liquid) Electrical Hazard Not pertinent Burning Rate Not pertinem. 

Vertical Pressure Leaf Filters are essentially the same as Horizontal Plate Filters except for the orientation of the filter elements which are vertical rather than horizontal. They are applied for the polishing slurries with very lov solids content of 1-5% or for cake filtration with a solids concentration of 20-25%. As with the horizontal plate filter the vertical leaf filters are also well suited for handling flammable, toxic and corrosive materials since they are autoclaved and designed for hazardous environments when high pressure and safe operation are required. Likewise, they may be readily jacketed for applications whenever hot or cold temperatures are to be preserved.The largest leaf filters in horizontal vessels have a filtration area of 300 m and vertical vessels 100 m both designed for an operating pressure of 6 bar. 

Bromine is considered a moderate fire hazard. As liquid or vapor, it can enter spontaneous chemical reactions with reducing materials. It is a very powerful oxidizer. Bromine is considered a highly dangerous material. Upon being heated, it emits highly toxic fumes. It will react with water or steam to produce toxic and corrosive fumes. 

This is a clear liquid that vaporizes and, on contact with damp air, combines with w ater to produce a dense acid mist. Titanium tetrachloride can be painted on to surfaces, such as fume cupboard sills, from which it will evaporate over a period of several seconds showing the airflow patterns close to the surface. (Airflow patterns close to a surface could also be visualized by fastening short filaments of wool or cotton to the surface). Titanium tetrachloride can also be used, when soaked onto a cotton swab, in a similar way to a smoke tube. It is a simple and inexpensive method but the production of smoke, which is toxic and corrosive, is uncontrollable. 

Sulfur dioxide is extremely stable to heat, even up to 3600°F. It docs not form flammable or cxplosi c mixtures witli air. It will, howe cr, react with water or steam to produce toxic and corrosive fumes.When the gas dissolves in water it forms a weak acid solution of sulfurous acid (H S03), which is corrosi C [Pg.274]

Service Air Refrigeration at -175 F Hydrogen Reforming Wet Gas Toxic and Corrosive Gases Coke Oven... 

Some disadvantages stem from the same phenomena impeded diffusion reduces the maximum practical rate of plating to well below that possible with aquocation baths. The cyanide ion is not entirely stable both oxidation and reduction products accumulate, including carbonate. Carbonate is also formed in the alkaline cyanide baths (all cyanide baths are alkaline except some based on aurocyanides) by absorption of COj from the air, and it is necessary either to replace or purify baths periodically. Much has been made of the toxicity of cyanides, but the other process solutions used in plating are generally extremely toxic and corrosive or caustic, and it is necessary to treat them all with respect. 

Disaster hazard. Phosgene is highly dangerous. When heated to decompn, or on contact with w or steam, it wiii react to produce toxic and corrosive fumes (Ref 12). Powdered A1 burns in its vapor (Ref 3)... 

A major disadvantage of CVD (as opposed to PVD) is that many precursors are toxic and in some cases lethal even at low concentration (for instance nickel carbonyl, diborane, arsine, and phosphine). Some are also pyrophoric, such as silane, some alkyls, arsine, and phosphine. Very often the reaction is not complete and some of the precursor materials may reach the exhaust unreacted. In addition, many of the by-products of the reaction are also toxic and corrosive. This means that all these effluents must be eliminated or neutralized before they are released to the... 

Sulfur dioxide A toxic and corrosive gas emitted continuously in dilute form, principally from the burning of fossil fuels. 

Hydrochloric acid and sulfuric acid are toxic and corrosive to skin and react with metals. 

Decomposition Toxic and corrosive vapors are produced when combined... 

DF and its precursor, methylphosphonic dichloride (DC), are organophos-phonic acids. They will react with alcohols to form crude lethal nerve agents, such as crude GB. High overexposure may cause inhibition of cholinesterase activity. Although much less toxic than GB, DF and DC are toxic and corrosive materials. 

DF and its precursor, DC are organophosphonic acids. They will react with alcohols to form crude lethal nerve agents, such as crude GB. High overexposure may cause inhibition of cholinesterase activity. Although much less toxic than GB, DF and DC are toxic and corrosive materials. Because DF and DC are relatively volatile compounds, the primary route of exposure is expected to be the respiratory system. However, ingestion also results from inhalation exposures in animals and could occur in humans. DF and DC vapors have a pungent odor and may cause severe and painful irritation of the eyes, nose, throat, and lungs. Data provided is for DF only, DC has similar properties. 

Many essential transformations of carbohydrates regularly employ toxic and corrosive reagents, such as Lewis acids and strong mineral acids. Hence, the use of zeolites and related porous solids as catalysts in such reactions affords a practical and environmentally compatible alternative to the standard protocols. 

Techniques are available to quantify the generation of smoke, toxic and corrosive fire products using the NBS Smoke Chamber (15), pyrolysis-gas chromatography/mass spectrometry (PY-GC-MS) (J 6), FMRC Flammability Apparatus (2,3,5,17,18), OSU Heat Release Rate Apparatus (13) and the NIST Cone Calorimeter (JJO. Techniques are also available to assess generation of 1) toxic compounds in terms of animal response (19), and 2) corrosive compounds in terms of metal corrosion (J 7). In the study, FMRC techniques and AMTL PY-GC-MS techniques were used. 

Generation of Smoke, Toxic and Corrosive Fire Products. Smoke, toxic and corrosive products are generated in fires as a result of vaporization, decomposition and combustion of materials in the presence or absence of air. 

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