Combustion vapors or gases

Specifically designated electrical equipment can be manufactured so that its internal components are completely sealed. This eliminates the possibility electrical arcing components or circuits can contact combustible vapors or gases. 

Enclosed locations will not receive adequate ventilation and could allow the build-up of combustible vapors or gases. Vapors with heavy densities can be particularly cumbersome as they will seek the low areas that are normally not provided with fresh air circulation. 

The obvious hazards in the syntheses reported in this volume are delineated, where appropriate, in the experimental procedure. It is impossible, however, to foresee every eventuality, such as a new biological effect of a common laboratory reagent. As a consequence, all chemicals used and all reactions described in this volume should be viewed as potentially hazardous. Care should be taken to avoid inhalation or other physical contact with all reagents and solvents used in this volume. In addition, particular attention should be paid to avoiding sparks, open flames, or other potential sources that could set fire to combustible vapors or gases. 

To assist in the location of air inlets for ventilation systems and combustion equipment (i.e., to prevent the ingestion of combustible vapors or gases)... 

All areas that are subject to a possible vapor cloud formation should be provided with maximum ventilation capability Specific examination should be undertaken at all areas where the hazardous area classification is defined as Class 1, Division 1 or Class If Division 2. These are areas where hydrocarbon vapors are expected to be present, so verification that adequate ventilation is provided to aide in the dispersion of combustible vapors or gases is necessary The following practices are preferred ... 

Release or exposure of combustible vapors or gases to the atmosphere should be avoided. 

Waste combustible vapors or gases (process vents, relief valves, and blowdown) should be routed to the flare or returned to the process through a closed header. 

Judicious placement of fans during the initial stages of plant design can also serve as help in the dilution of combustible vapors or gases during an incident. 

Perimeter Monitoring—The perimeter of a hazardous area or process unit can be effectively monitored for a gas or vapor release by IR beam arrangements on the edges. Theoretically they can be used to warn of open air combustible vapors or gases approaching ignition sources in a reverse role, e.g., to the flare from a process area. 

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