Topic 61: Reactive Hazards
Hazard is defined as a chemical or physical condition that has potential to cause harm to human life, property or the environment and a reactive hazard has potential to initiate a reactive incident. It is an outcome of changes to chemical structure leading to rapid release of energy, heat and gaseous products leading to severe consequences e.g. fire, explosion, or toxic release.
A reactive hazard may involve:
Impact or thermal sensitive self-reactive
chemicals that may rapidly decompose resulting in a potential explosive release
Chemical incompatibility between two or more
Examples of uncontrolled industrial chemical reactions that
can be considered as potential reactive hazards are polymerisation,
decomposition, acid -base, oxidation reduction and reaction with water.
The severity of reactive hazards also depends on various
process conditions such as temperature, pressure, chemical concentrations,
impurities, catalytic effects, chemical inventory, etc.
Incidents from reactive hazards can severely affect workers
and the public and cause major economic losses and environmental damages. The
US Chemical safety and Hazard Investigation Board (USCSB) has information of
167reactive incidents out of which 48 caused a total of 108 fatalities with an
average of six injury related incidents. Two of the most serious industrial
accidents resulting from poor understanding/ management of reactive hazards are
Bhopal Accident, 1984 (>10000 fatalities and >500000 injuries) and Seveso
Accident at Italy, 1976.
HSE legislation and guidelines associated with Reactive
Health and safety at Work Act 1974,
Chemicals (Hazard Information and Packing for
Supply) Regulation (CHIPS) – Risk Phrases.
Dangerous Substances and Explosive Regulations
Implementation of ATEX 137 Directives
Control of Industrial Major Accident Hazards
(Seveso II Directive)
CLP (Classification, Labelling, Packaging)
NFPA 400 Hazardous Material code
NFPA 704 Standard System for the Identification
of Hazards of Material for Emergency Response
NIOSH Pocket guide to Chemical Hazards
Centre for Chemical Process Safety (CCPS) –
Essential Practices for Managing Chemical reactivity Hazards
Management of reactive hazards is essential for safe design,
operation and maintenance of any oil and gas or chemical industry and mainly
involves thorough identification and evaluation of potential reactive hazards
and mitigation of associated risks.