Reactive and incompatible chemicals

Incompatibilities and Reactivities Chemically-active metals such as sodium, potassium magnesium fluorine aluminum [Note Forms highly toxic phosgene gas yirhen exposed to flames or welding arcs.] ... 

Incompatibilities and Reactivities Chemically-active metals such as sodium, potassium, calcium, ... 

CHEMICAL PROPERTIES normally stable, even under fire exposure conditions hazardous polymerization will not occur does not react with water when oxidation and peroxidation occurs in mineral oils it continues almost at a logarithmic rate no incompatibilities and reactivities reported FP (193°C, 380°F (open cup), 135°C, 275°F (closed cup)) LFL/UFL (unknown) AT (260-371°C, 500-700°F). 

CHEMICAL PROPERTIES noncombustible solid high resistances to acids, alkalies, and heat no incompatibilities and reactivities reported FP (NA) LFL/UFL (NA) AT (NA) HC (NA). 

CHEMICAL PROPERTIES combustible liquid antioxidants may be added to prevent breakdown during storage and to insure maximum stability no incompatibilities and reactivities reported FP (161.7-282°C, 323-540°F) LFLAJFL (unknown) AT (unknown) HC (unknown) HF (unknown). 

Incompatibilities and Reactivities Strong oxidizers chemically-active metals... 

Incompatibilities and Reactivities Strong caustics chemically-active metals such as aluminum or magnesium powder, sodium potassium strong oxidizers [Note When heated to decomposition, fornis phosgene gas]... 

Incompatibilities and Reactivities Oxidizers, strong acids, chemically-active metals (e g., potassium, sodium, magnesium, zinc) ... 

Incompatibilities and Reactivities Strong caustics strong oxidizers chemically-active metals such as zinc, aluminum, magnesium powders, sodium potassium water... 

Incompatibilities and Reactivities Concentrated nitric acid, nitrogen tetroxide, caustics, phosphorus pentachloride, chemically-active metals such as tin or zinc ... 

Incompatibilities and Reactivities Water, magnesium oxide, chemically-active metals such as sodium and potassium, alkalis, amines... 

Examine the hazardous characteristics of each process chemical. Review the MSDSs, which should have information on the toxicity, flammability, and reactivity of process chemicals and on their incompatibilities with other materials. 

Lacking actual test results, the next best option is to check chemical-specific safety data such as MSDSs or International Chemical Safety Cards (ICSCs) for the particular compounds and concentrations involved. Section 10 (Stability and Reactivity) of standard MSDSs should contain information on Incompatibilities with Other Materials. Similar information should be in the Chemical Dangers section of ICSCs. However, these are rarely more than lists of incompatible materials, and do not indicate what consequences can be expected. The listed incompatibilities should be considered as only applying to ambient conditions. 

References on incompatibilities, such as Bretherick s Handbook of Reactive Chemical Hazards (Urben 1999), Sax s Dangerous Properties of Industrial Materials (Lewis and Irving 2000) and NFPA 491, Hazardous Chemical Reactions (NFPA 2002), summarize published literature and incidents on incompatibilities. They may give more detailed information on what to expect when specific materials are combined. 

MSDSs generally contain the most apparent chemical reactivity hazards. However, they cannot be relied upon to give complete information, particularly with regard to chemical incompatibilities and chemical reactivity at actual process conditions. 

No general rules or easy answers exist for understanding the potential consequences of uncontrolled chemical reactions, due to the diversity of chemicals and reaction pathways. Table 4.5 shows the potential consequences of oxidizers as one specific category of reactive chemicals. Table 4.6, taken from the NOAA Chemical Reactivity Worksheet, lists some general consequences that could occur if incompatible materials are combined. 

The Preliminary Screening Method is not intended to identify all conditions under which reactive chemicals and incompatibilities may lead to uncontrolled reactions. However, it should give an indication whether chemical reactivity hazards exist, as well as what to investigate more closely by analysis and testing. 

Responses to the CSB industry survey50 indicate that most companies consult a variety of information sources as a first step in compiling data on reactive hazards. However, respondents prefer literature sources and expert opinion over computerized tools such as CHETAH, The Chemical Reactivity Worksheet, or Bretherick s Database of Reactive Chemical Hazards. Such programs can be used to predict the thermal stability of compounds, reaction mixtures, or potential chemical incompatibilities. In some cases, they provide an efficient means of identifying reactive hazards without having to conduct chemical testing. Survey responses showed that five of nine companies consider computer-based tools not valuable. Only two of the surveyed companies use The Chemical Reactivity Worksheet.51... 

Approximately 36 percent of incidents in the CSB data are related to chemical incompatibility. CCPS provides information on managing chemical incompatibility hazards in guidelines for chemical reactivity. It emphasizes the need to systematically examine possible chemical incompatibilities and describes the use of interaction matrices (CCPS, 1995a, p. 7 1995b, p. 108).52>,53 This guidance applies to chemical manufacturers as well as to other industries. 

Bretherick s Handbook of Reactive Chemicals Summaries of reactivity, incompatibility, and other dangerous properties of individual substances either alone or in combination case histories Butterworth-Heinemann... 

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