ASSESSING AND MANAGING RISKS IN HAZARDOUS AREAS

ASSESSING AND MANAGING RISKS IN HAZARDOUS AREAS BY FRANS WILBRINK WILBRINK & ASSOCIATES

OUTLINE • Classify the different types of hazardous areas • Identify the risks associated with each of these areas • Identify a risk rating for each risk • Using a hierarchy to control or mitigate the risks • Implement controls to mitigate these risks • Ongoing evaluation of the risks in order to improve the environment further

HAZARDOUS AREAS • Areas that are dangerous to health e.g. Lead or Asbestos areas • Areas that are very corrosive e.g. Acid plant • Spontaneous combustion areas e.g. Mixed chemical warehouse with oxidizing / reducing agents • Flammable areas, e.g. Solvent plants • Explosive areas e.g. Flour silo or areas where the ‘solvent’ content in the air is within the explosive range

AREAS HAVING A HEALTH RISK • We must be aware that we are working with a chemical that may pose a health risk. This is best done through a Hazardous Chemical Risk Assessment (Reg. 5 HCR) • Through the assessment we would know the risk rating for each chemical and its inherent dangers • Air monitoring is done to confirm the levels identified in the Risk Assessment • We would identify methods of reducing the risks, e.g. extraction system or dampening the floor, using a vacuum system for housekeeping

AREAS HAVING A HEALTH RISK • Medical surveillances would be carried out on the employees • The risk assessments and air monitoring as well as the medicals would be repeated at least once every two years • All equipment used to reduce the levels (control equipment) must be tested and certified every two years

VERY CORROSIVE AREAS • The Chemical Risk Assessment and air monitoring should be carried out to determine effects (risks) and air born levels • The levels should be reduced as far as possible. This could be done by closing leaks, designing the plant to be a closed system and neutralizing any waste stream e.g. Exhaust fumes. This can be done using scrubbers. • As far as possible all equipment used should be resistant to the specific chemical attack. The initial cost may be high but it pays in the long term

VERY CORROSIVE AREAS • The monitoring must be ongoing. There are sensors that can be installed to sound an alarm when the levels exceed certain levels • Medicals must also be carried out on all employees on a regular basis • Non-destructive testing should be carried out on reactors / pipes / storage vessels to ensure the integrity of the equipment is still in place. The frequency should be determined from the potential corrosion rate

Example of fixed sensors

SPONTANEOUS COMBUSTION • Some chemicals are not compatible with other e.g. Oxidizing / Reducing agents, Acids / Bases • If non-compatible chemicals come in contact with one another they will react. The heat generated could lead to a large fire. • This can be prevented by storing goods as per the compatibility chart (SANS 10232 -1 & -2) • It is also recommended to have all chemical storage areas monitored by smoke detectors and covered by a foam sprinkler system

FLAMMABLE AREAS • These are areas where there could be an elevated concentration of flammable material (solvent plant, a refinery, a resin manufacturing unit) • In the event of a mixture of the flammable product, oxygen and energy (spark) a fire or even an explosion can take place • These areas very often also pose a health risk to the workers • To determine the risks, we need a Health Risk Assessment and a Fire / Explosion Risk Assessment

EXPLOSIVE AREAS • These are areas where there could be the right concentration of product (powders e.g. Inorganic dust, organic dust, plastics, resins, foods, solid fuels) • In the event of the right concentration of product, oxygen and energy (spark) an explosion can take place • These areas very often also pose a health risk to the workers • To determine the risks, we need a Health Risk Assessment and a Fire / Explosion Risk Assessment

CLASSIFICATION OF AREAS • All areas and sub areas need to be classified according to SANS 10108. The classification will determine the class required for all electrical equipment • All areas to be classified as zone 0, zone 1 and zone 2 in the case of liquids • In the case of dust, the classification is zone 20, zone 21 and zone 22 • All areas have different requirements for their electrical equipment

CLASSIFICATION OF AREAS (Cont) • All electrical equipment from a switch to a heavy duty motor must comply to the requirements of this assessment • All equipment must be supplied with a certificate that they comply • All equipment must be inspected / tested at least once every two years and all findings entered into a register • If any equipment is opened, it must be re-certified

HEALTH RISK ASSESSMENTS • A Health Risk Assessment is required in terms of the OH&S Act (Hazardous Chemicals Regulations). Products that we may classify as non hazardous are classified in terms of these Regulations • The dangers of the various chemicals should be highlighted in this risk assessment (i.e. What effect they have on the body) • This RA will assist in determining the preventative measures that need to be taken (extraction, PPE, medicals or replacement)

FIRE & EXPLOSION R.A. • A Fire & Explosion Risk Assessment will determine the risk rating and also highlight where the highest risks are • All products are allocated a Material Factor (MF) • One than goes through the general process hazards and special process hazards. These factors are multiplied to give us a process hazard factor. • This factor multiplied with the MF gives us the Fire and Explosion index

FIRE & EXPLOSION R.A. (Cont) • We than look at the three credit factors, i.e. Process control credit factor (C1), Material isolation credit factor (C2) and Fire protection credit factor (C3) • The sum of each credit factor is multiplied with the other credit factors to give loss control credit factor, i.e. C1 X C2 X C3 = Loss Control Credit factor • Implementing certain procedures, installing certain equipment and automation will reduce the risks

HIERARCHY TO CONTROL • Taking the Classification of Hazardous locations, the Hazardous Chemical RA and the Fire & Explosion RA we determine the highest risk (area / equipment / chemical etc) and determine what can be done to reduce the risks • Once we have decided on ways to reduce the risks, we re-calculate the remaining risks and see if we can not reduce the risks further • We also implement training as well as proper documented procedures – they will help to reduce the risk

CONTROLS • Controls should be implemented to reduce risks (how to change procedures, how to introduce new chemicals, how to do changes to the process etc) • These controls need to be checked on a regular basis to ensure that people do not bypass them • Regular meetings between the various disciplines should take place (Engineering, Production, Laboratory, R&D) to find ways to reduce the risks further • Outside inspections to verify methods to reduce risks

ONGOING EVALUATION • In order to do an ongoing evaluation management must be fully familiar with the methods used to determine risks • Critical analysis should take place at least once a year to determine new methods to reduce the risks • Making use of an outside consultant normally brings in new ideas to reduce the risks further • Monitoring of all aspects is required on an ongoing basis • A proper maintenance program is of utmost importance

ASSESSING AND MANAGING RISKS IN HAZARDOUS AREAS