Initial screening explosion

Explosihility screening. In the literature an extensive collection of explosion properties of chemical compounds can be found. However, if literature is unavailable or properties have not been examined yet, a number of initial screening techniques exist. If the checks for explosibility of the starting materials, intermediates, or products reveal a great hazard from deflagration or detonation, it is advisable to abandon the process. 

Initial screening (Section 3.2) —Through identification of materials and conditions present at the specific site Material Safety Data Sheets Process conditions Total inventory of materials being handled Information on site conditions as needed to evaluate explosion or fire potential... 

National Fire Protection Association. System gives a qualitative rating for health, flammability, and spontaneity. These values range from 0 to 4, with 4 being the most hazardous. These can be used for an initial screen to sensitize engineers to the potential hazard. Quantitative values are published elsewhere for each separate issue health (TLV, STEL, IDLFl) flammability explosivity (upper and lower explosive limits). 

At present, there are no specific guidelines for assessing similar risks from trace gases and vapours. However, an initial assessment can normally be made using the same principles that have been applied to methane (i.e. consider 20% of the lower explosive limit as an initial screening value below which risks are... 

The initial, consequence, or risk screening results indicated that the building was designed or sited such that it was not a concern relative to explosion or fire events. As a result, the building was screened out as not needing further consideration. 

Many of the original puzzles and concerns considered before initial deployment of explosive detection equipment have not been resolved, but less than optimal solutions have had to be accepted. For example, an alarm is usuaUy resolved by re-screening of the object, hand examination of the alarming item, or questioning of the owner. None of the presently fielded techniques address the need to determine whether a liquid threat material has been sealed in a bottle. There was a short period of time after the terrorist attacks of 11 September 2001 when people wishing to carry a bottle of liquid on board an airplane were required to take a sip of it to demonstrate it was innocuous. Since the threat from liquid explosives in the... 

Substances which explode by a weak impact (called highly sensitive substances) can be identified by a screening test like the drop ball test Whether deflagration occurs easily can be checked by an ignitability test Another screening test to examine the ease of occurrence of a reaction relies on the determination of the temperature at which decomposition is initiated by thermal analysis on micro-samples. This quantifies the ease of initiating a thermal explosion. 

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