Risk assessment – an example
One simple way to carry out a risk assessment is to follow the five steps in the template provided in a Training Package on Workplace Risk Assessment developed by ILO as indicated below;
Identify the hazards.
Identify who might be harmed and how.
Evaluate the risk – identify and decide on the safety and health risk control measures, involving two sub-steps:
What you are already doing in terms of existing risk control measures?
What further risk control measures are necessary?
Record who is responsible for implementing which control measures and the timeframe. Implement the safety and health risk control measures (deciding who is responsible for doing what, and by when).
Monitor and review your risk assessment, and update when necessary.
Example of a risk assessment template. Click to expand. (Reproduced by permission from ILO) (PDF version)
Drilling in a mine. © S.H.D. Mamuya
Risk assessment - An example of drilling in mining:
A manager is carrying out a risk assessment among drillers in an underground gold mine. The drillers use pneumatic jackhammers. After some years in this mine several of the drillers developed lung problems, and the owner realizes that safety and health practices need to be improved in this regard.
Step 1: Identifying the hazards
There are a number of hazards in this work environment such as noise, vibrations, heat, lack of oxygen and falling rocks. However, we will focus on the hazards relevant for the lung problems. When drilling in hard rock, one should be aware of the dust produced, and in particular, the possible crystalline silica content in the respirable fraction of the dust. In addition, the oil vapour and oil mist from the pneumatic equipment as well as gases and fumes from the blasting process are also potential chemical hazards that are relevant for respiratory problems.
Step 2: Who is at risk and how?
In this mine, 20 drillers and assistants are at risk of exposure to dust during drilling. They are also responsible for the blasting process, and when they re-enter the drilling face after blasting they can be exposed to dust from the blasted rocks, as well as to blasting fumes, nitrogen dioxide and ammonia.
Step 3: Evaluating the risk – what action is necessary to reduce the risk
3.A: What is being done now?
There is a one-way ventilation system, which supplies fresh air to the face, while dust and fumes are ventilated passively through the tunnel cavity. Other controls measures to reduce dust and fume exposure have not been established. Respiratory protective devices are not provided.
The manager acknowledges that the drilling team re-enters the drilling face before the blasting fumes and dust are sufficiently ventilated away. This can be considered poor work organisation and procedures, including the lack of warning before re-entering.
3.B: What further action is necessary – Risk reduction measures
The manager, together with the Health and Safety-engineer and one worker representative are now working systematically through possible risk control measures.
Risk Control Measure 1: Eliminating the hazard. This is always the best solution, but in mining it is not possible to eliminate the hazards related to dust exposure, but several other measures can be used to reduce exposure levels.
Risk Control Measure 2: Tools, equipment, technology and engineering.
- A two-way ventilation system should be installed; Two separate ventilation ducts, -one to supply fresh air and one to remove contaminated air.
- Various dust suppression techniques should be established to reduce or contain dust emissions while drilling and blasting
• A flexible rubber skirt that encloses the drill hole opening and captures cuttings and dust from the hole.
• A dust suppressant, such as water, reduces airborne dust during drilling.
• A local exhaust ventilation system will capture dust at the drill hole.
• Unless immediate measures are initiated to reduce the dust levels, respiratory protective masks should be used.
Risk Control Measure 3: Safe work methods, practices, organization, information and training.
Proper training, work organization, safe work practice and dust suppression techniques should be emphasized. The following measures are identified for implementation:
- The drilling team and their supervisors will receive extra training on the importance of respecting re-entry time after blasting. Warning signs will be placed at the entrance, and no one is permitted to pass this point before the supervisor removes the warning sign.
- They will also be trained in how to use dust suppression methods when drilling.
- Any possible work-related ill health will be noted in the mine’s accident and disease recording book.
Risk Control Measure 4: Hygiene and welfare.
Wash rooms and lockers to store workers’ personal belongings, personal protective equipment and food are provided near the main office, well away from exposed areas.
Risk Control Measure 5: Personal protective equipment.
Due to the health risk related to exposure to crystalline silica, proper personal respiratory masks are needed when drilling, and should continue to be used even after dust suppressive methods are established. The new working procedures should also ensure that workers are less exposed when re-entering after blasting.
These improvements in procedures, equipment, communication, information and training mean that the manager will now give clear instructions to supervisors and workers on how drilling will be carried out to lower the risk of respiratory effects.