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 & -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 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