Chemical reactivity hazard defined

Somewhat different organizational structures may be needed for managing different kinds of chemical reactivity hazards. As defined in Section 1.3, three general situations involving chemical reactivity hazards are as follows ... 

A Glossary defines terms related to chemical reactivity hazards. 

Up to this point, the chemical reactivity hazards of individual substances, either by themselves or in contact with common environmental materials, have been considered. This last question in the chemical reactivity hazards screening will address the potential for an unintended chemical reaction due to incompatible materials contacting each other. Compatibility, in this context, means the ability of materials to exist in contact without specified (usually hazardous) consequences under a defined scenario. A scenario, in this context, is a detailed physical description of the process whereby a potential inadvertent combination of materials may occur (ASTM E 2012-00). 

In order to maximize the benefit of any identified improvement, administrative procedures should be created and implemented which define distribution or lines of communication for information related to chemical reactivity hazard management improvements. Examples of such lines include those from laboratories to pilot plants to production facilities. 

The term can refer to any undesired results occurring when substances are combined. In the context of this publication, it refers to incompatible substances giving an undesired chemical reaction when combined, posing a chemical reactivity hazard under a defined scenario. 

CCPS (1989) defines a hazard as a chemical or physical condition that has the potential to cause harm to human life, property, or the environment. A reactive hazard has the potential to lead to a reactive incident (Section 1.3). 

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. 

Another requirement of the PSM Standard is that the employer conduct process hazard analysis, which OSHA defines as an organized and systematic effort to identify and analyze the significance of potential hazards associated with the processing or handling of highly hazardous chemicals. The analysis must identify the hazards of the process and necessary safeguards however, the standard does not explicitly define requirements for addressing reactive hazards. 

When developing the list of substances, EPA considered only the inherent characteristics of a chemical that indicate a severe threat due to exposure. Well-defined criteria were used for toxicity and flammability. However, because of the complexities of site-specific factors and process conditions, EPA was unable to determine any inherent characteristic as an indicator of reactivity. EPA concluded that there was insufficient technical information for developing criteria for identifying reactive substances. 46 Consequently, the January 1994 RMP list of 130 chemicals does not contain any substances listed due to reactive hazards. 

Certain structural features, including whether it contains functional groups such as aldehydes, ketones, nitriles, or isocyanates, often define a class of chemicals. If information on the mechanism of action of a hazardous property of a chemical is not known, or if variances in the chemical s hazard through structural modification cannot be determined, then the assumption that certain chemically reactive functional groups can react similarly with the body or in the environment is often a good starting point in the process of evaluating the safety of solvents. 

Hazardous chemical waste is defined in RCRA regulations as a solid waste that exhibits the characteristic of ignitability, corrosivity, reactivity, or toxicity, or is a specifically listed waste. The definition of hazardous waste specifically excludes radioactive material (source, special nuclear, or byproduct material) defined in AEA. 

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