Reactive hazards mixtures

Reactive hazards, 44, 228 explosive, 235 mixtures, 231, 468 pyrophoric, 17, 214 thermal runaway, 252 unstable, 228 water-sensitive, 228... 

Example 1 Typical Outputs of Thermal Stability Test Methods As discussed in detail later in Section 2.3, various techniques with different working principles are available to identify the thermal reactivity hazards of individual substances and reaction mixtures. Some examples are presented here. 

For the purposes of this investigation-rather than adopting any single definition of a reactive chemicaT-CSB focuses on the broadest range of practices to identify reactive hazards and to manage the risk of reactive incidents. A reactive chemical may include any pure substance or mixture that has the capability to create a reactive incident. CSB defines a reactive incident as a sudden event involving an uncontrolled chemical reaction-with significant increases in temperature, pressure, or gas evolution-that has caused, or has the potential to cause, serious harm to people, property, or the environment. 

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... 

In both the OSHA PSM Standard and the EPA RMP regulation, the PHA element does not currently specify the factors that must be considered to effectively manage reactive hazards. Present requirements should be augmented to explicitly require an evaluation of such factors as rate and quantity of heat generated maximum operating temperature to avoid decomposition thermostability of reactants, reaction mixtures, byproduct waste streams, and products effect of charging rates, catalyst addition, and possible contaminants and understanding the consequences of runaway reactions or toxic gas evolution. 

Reactive hazard Reactive properties and physical conditions of a single chemical or mixture that have the potential to generate heat, energy, and gaseous byproducts that have the potential to do harm. 

ASTM also distributes the computer program CHETAH (Chemical Thermodynamic and Energy Release Evaluation), a tool for predicting both thermodynamic properties and certain reactive hazards associated with a pure chemical, a mixture of chemicals, or a chemical reaction. 

The liquid alloy gives mixtures with halocarbons even more shock-sensitive than those with potassium. Highly chlorinated methane derivatives are more reactive than those of ethane, often exploding spontaneously after a delay [1]. Contact of 1,1,1-trichloroethane with a trapped alloy residue in a valve caused an explosion [2], It is to be expected that chlorofluorocarbons will also form hazardous mixtures in view of their reactivity with barium. Precautionary measures for demonstrating the explosion of the alloy with chloroform are detailed [3]. Addition of 2 drops of 1,1,2-trichloro-trifluoroethane to the alloy caused a violent explosion [4],... 

A4.3.10.1.1 Describe the reactivity hazards of the substance or mixture in this section. Provide specific test data for the substance or mixture as a whole, where available. However, the information may also be based on general data for the class or family of chemical if such data adequately represent the anticipated hazard of the substance or mixture. 

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