WHAT IS A HAZARD?

When we refer to Hazards in relation to occupational health and safety (Public Health) the most commonly used definition is: 

 ‘Hazard is a potential source of harm or adverse health effect on a person or persons’.  

Health and safety hazards exist in every workplace. Some are easily identified and corrected, while others create extremely dangerous situations that could be a threat to the worker’s life or long-term health. In particular, occupational hazards include all those work activities and processes involving the worker, raw materials, and processing activities such as operating machinery and handling chemicals. Most occupational hazards are inactive or have a low potential of actually occurring; the risk of harm is largely theoretical. However, once a hazard becomes active, it can generate an emergency situation. 

Hazards can appear in many working circumstances. Some hazards pose an immediate danger, while others take a longer time to materialize. Hazards can be classified as:

• Physical Hazards: These are the most common hazards and they include extremes of temperature, ionizing/non-ionizing radiation, excessive noise, electrical exposure, working groom heights, unguarded machinery, etc.

• Mechanical Hazards: These are usually created by machinery, protruding and moving parts.
• Chemical Hazards: These appear when a worker is exposed to chemicals in the workplace. Some are safer than others, but to some workers who are more sensitive to chemicals, even common solutions can cause illness, skin irritation or breathing problems.
• Biological Hazards: These include the existence of viruses, bacteria, fungus, parasites, or any living organism that can cause disease to human beings.
• Ergonomic Hazards: These include considerations of the total physiological demands of the job upon the worker even beyond productivity, health and safety.
• Psychosocial Hazards: These may arise from a variety of psychosocial factors that workers may find to be unsatisfactory, frustrating or demoralizing.

The recognition of hazards has often come from observations of undesirable health effects among workers.

WHAT IS A HAZARD CONTROL PROGRAM?

A hazard control program consists of all measures necessary to protect workers from exposure to a substance or system, the training and the procedures required to monitor worker exposure and their health to hazards such as chemicals, materials or substance, or other types of hazards such as noise and vibration. A written workplace hazard control program should outline which methods are being used to control the exposure and how these controls will be monitored for effectiveness. The hazard control program would spell out all necessary hazard control measures (HAZCOM)  to be adopted in the specific organisation. 

WHAT ARE HAZARD CONTROL MEASURES (HAZCOM)? 

Hazard control measures include actions that can be taken to reduces the potential of exposure to the hazard, or the control measure could be to remove the hazard or to reduce the likelihood of the risk of the exposure to that hazard being realised. A simple control measure would be the secure guarding of moving parts of machinery eliminating the potential for contact. 

WHERE ARE CONTROLS USED?

Controls are usually placed:

1. At the source (where the hazard "comes from").
2. Along the path (where the hazard "travels").
3. At the worker.

Control at the SOURCE and control ALONG THE PATH are sometimes also known as engineering controls (see below for details)

When we look at control measures we often refer to the hierarchy of control measures.

1. IDENTIFICATION OF THE HAZARD:  

The first and most important step is to identify any potential and actual hazard in real time and knowing how to go about it. This can be achieved by the use of HazID.

HazID stands for hazard identification. It is more of a general risk analysis tool designed to alert management to threats and hazards as early in the process as possible. The classification made is done on the basis of probability and consequences. HazID study provides a qualitative analysis of a worksite in order to determine its worker safety risk level. 

2. ELIMINATION OF THE HAZARD 

Elimination is the process of removing the hazard from the workplace. It is the most effective way to control a risk because the hazard is no longer present. It is actually the preferred way to control a hazard and should be used whenever possible.

3. SUBSTITUTION OF THE HAZARD WITH A LESSER RISK

Substitution occurs when a new chemical or substance that is less hazardous is used instead of another chemical. It is sometimes grouped with elimination because, in effect, you are removing the first substance or hazard from the workplace. The goal, obviously, is to choose a new equipment, chemical, substance or material that is less hazardous than the original.

The table below provides some examples:

However, substituting the hazard may not remove all of the hazards that are associated with the process or activity and may introduce different hazards but the overall harm or health effects will be lessened. In laboratory research, toluene is now often used as a substitute for benzene. The solvent-properties of the two are similar but toluene is less toxic and is not categorised as a carcinogen although toluene can cause severe neurological harm.

Remember, that you need to make sure the substitute chemical or substance is not causing any harmful effects, and to control and monitor exposures to make sure that the replacement chemical or substance is below occupational exposure limits.

Another type of substitution includes using the same chemical but to use it in a different form. For example, a dry, dusty powder may be a significant inhalation hazard but if this material can be purchased and used as pellets or crystals, there may be less dust in the air and therefore less exposure.

Remember!

When substituting, be very careful that one hazard is not being traded for another. Before deciding to replace a chemical/substance with another, consider all the implications and potential risks of the new material.

4. ISOLATION/ENCLOSURE OF THE HAZARD

These methods aim to keep the harmful parts of the equipment,  or the chemical "in" and the worker "out" (or vice versa).

An enclosure keeps a selected hazard "physically" away from the worker. Enclosed equipment, for example, is tightly sealed and it is typically only opened for cleaning or maintenance. Other examples include "glove boxes" (where a chemical is in a ventilated and enclosed space and the employee works with the material by using gloves that are built in), abrasive blasting cabinets, or remote control devices. Care must be taken when the enclosure is opened for maintenance as exposure could occur if adequate precautions are not taken. The enclosure itself must be well maintained to prevent leaks.

also, ISOLATION places the hazardous process "geographically" away from the majority of the workers. Common isolation techniques are to create a contaminant-free booth either around the equipment or around the employee workstations. Isolating the hazard is achieved by restricting access to plant and equipment or in the case of substances locking them away under strict controls. When using certain chemicals then a fume cupboard can isolate the hazard from the person, similarly placing noisy equipment in a non-accessible enclosure or room isolates the hazard from the person(s).

5. USE OF ENGINEERING CONTROLS

Engineering controls are methods that are built into the design of a plant, equipment or process to minimize the hazard. Engineering controls are a very reliable way to control the worker's exposure as long as the controls are designed, used and maintained properly. The basic types of engineering controls are:

• Process control.
• Enclosure and/or isolation of emission source.
• Ventilation.

Process Control

Process control involves changing the way a job activity or process is done to reduce the risk. Monitoring should be done before and as well as after the change is implemented to make sure the changes did result in lower exposures.

Examples of process changes include to:

• Use wet methods rather than dry when drilling or grinding. "Wet method" means that water is sprayed over a dusty surface to keep dust levels down or material is mixed with water to prevent dust from being created.
• Use an appropriate vacuum or "wet method" instead of dry sweeping (e.g. with a broom) to control dust and reduce the inhalation hazard.
  • Note: Never use a regular "household" vacuum cleaner, especially when cleaning toxic material such as lead, or asbestos. Use a vacuum specifically designed for industrial workplaces and be sure to use appropriate filters, etc.
• Use steam cleaning instead of solvent degreasing (but be sure to evaluate the potential high temperature hazard being introduced such as heat stress).
• Use electric motors rather than diesel ones to eliminate diesel exhaust emissions.
• Float "balls" on open-surface tanks that contain solvents (e.g. degreasing operations) to reduce solvent surface area and to lower solvent loss.
• Instead of conventional spray painting, try to dip, paint with a brush, or use "airless"spray paint methods. These methods will reduce the amount of paint that is released into the air.
• Decrease the temperature of a process so that less vapour is released.
• Use automation - the less workers have to handle or use the materials, the less potential there is for exposure.
• Use mechanical transportation rather than manual methods.
• Engineering Controls involve redesigning a process to place a barrier between the person and the hazard or remove the hazard from the person, such as machinery guarding, proximity guarding, extraction systems or removing the operator to a remote location away from the hazard.

VENTILA

Ventilation is a method of control that strategically "adds" and "removes" air in the work environment. Ventilation can remove or dilute an air contaminant if designed properly. Local exhaust ventilation is very adaptable to almost all chemicals and operations. It removes the contaminant at the source so it cannot disperse into the work space and it generally uses lower exhaust rates than general ventilation (general ventilation usually exchanges air in the entire room).

Local exhaust ventilation is an effective means of controlling hazardous exposures but should be used when other methods (such as elimination or substitution) are not possible.

A local exhaust ventilation system consists of these basic parts:

1. A hood that captures the contaminants generated in the air (at the source).
2. Ductwork (exhaust stack and/or recirculation duct) that carries the contaminated air to the air cleaning device, if present or to the fan (away from the source).
3. A fan which draws the air from the hood into the ducts and removes the air from the workspace. The fan must overcome all the losses due to friction, hood entry, and fittings in the system while producing the intended flow rate.
4. Air cleaning devices may also be present that can remove contaminants such as dust (particulates), gases and vapours from the air stream before it is discharged or exhausted into the environment (outside air), depending on the material(s) being used in the hood. 

NOTE:  The design of a ventilation system is very important and must match the particular process and chemical or contaminant in use. Expert guidance should be sought. It is a very effective control measure but only if it is designed, tested, and maintained properly.

Because contaminants are exhausted to the outdoors, you should also check with your local environment ministry or municipality for any environmental air regulations or bylaws that may apply in your area.

6. USE OF ADMINISTRATIVE CONTROLS  

Administrative controls tend to limit workers' exposures by scheduling shorter work times in contaminant areas or by implementing other "rules". These control measures have many limitations because the hazard itself is not actually removed or reduced. Administrative controls are not generally favoured because they can be difficult to implement, maintain and are not a reliable way to reduce exposure. However, whenever  necessary, methods of administrative control should have include:

• Scheduling maintenance and other high exposure operations for times when few workers are present (such as evenings, weekends).
• Using job-rotation schedules that limit the amount of time an individual worker is exposed to a substance.
• Using a work-rest schedule THAT limits the length of time a worker is exposure to a hazard.

Work Practices

Work practices are also a form of administrative controls. In most workplaces, even if there are well designed and well maintained engineering controls present, safe work practices are very important. Some elements of safe work practices include:

• Developing and implementing standard operating procedures.
• Training and education of employees about the operating procedures as well as other necessary workplace training.
• Establishing and maintaining good house-keeping programs.
• Keeping equipment well maintained.
• Preparing and training for emergency response for incidents such as spills, fire or employee injury.

EDUCATION AND TRAINING

Employee education and training on how to conduct their work safely helps to minimize the risk of exposure and is a critical element of any complete workplace health and safety program. Training must cover not only how to do the job safely but it must also ensure that workers understand the hazards and risks of their job. It must also provide them with information on how to protect themselves and co-workers.

GOOD HOUSE-KEEPING

Good house-keeping is essential to prevent the accumulation of hazardous or toxic materials (e.g., build-up of dust or contaminant on ledges, or beams), or hazardous conditions (e.g., poor stockpiling). 

Administrative controls actually includes adopting standard operating procedures or safe work practices or providing appropriate training, instruction or information to reduce the potential for harm and/or adverse health effects to person(s). 

EMERGENCY PREPAREDNESS

Being prepared for emergencies means making sure that the necessary equipment and supplies are readily available and that employees know what to do when something unplanned happens such as a release, spill, fire or injury. These procedures should be written and employees should know all created muster points and also have the opportunity to practice their emergency response skills regularly through safety drills. 

ENVIRONMENTAL SANITATION, PERSONAL HYGIENE PRACTICES AND FACILITIES

A clean environment  is a healthy environment. As such,  a clean Environment and good personal hygiene practices are another very effective way to reduce the amount of  hazardous material absorbed, ingested or inhaled by a worker. They are particularly effective if the contaminant(s) can accumulate on the skin, clothing or hair.

Examples of personal hygiene practices include:

• Washing hands after handling material and before eating, drinking or smoking.
• Avoiding touching lips, nose and eyes with contaminated hands.
• No smoking, drinking, chewing gum or eating in the work areas - these activities should be permitted only in a "clean" area.
• Not storing hazardous materials in the same refrigerator as food items.

7. USE OF PERSONAL PROTECTIVE EQUIPMENT

Personal protective equipment (PPE) includes items such as respirators, protective clothing such as gloves, face shields, eye protection, and footwear that serve to provide a barrier between the person wearing it and the equipment, chemical or material.

It is always the final item on the list for a very good reason. Personal protective equipment should never be the only method used to reduce exposure except under very specific circumstances because PPE may "fail". 

However, no matter which type of PPE is used, it is essential to have a complete PPE program in place. 

Personal protective equipment (PPE) include gloves, glasses, earmuffs, aprons, safety footwear, dust masks which are designed to reduce exposure to the hazard. It must be emphasized clearly that PPE is usually seen as the last line of defence and is usually used in conjunction with one or more of the other control measures. 

Note: It is always best to try to eliminate the hazard first... 

Without adequate monitoring and review, no HAZCOM would be effective and result oriented. Hence let's look at some salient reasons why adequate monitoring and periodic review is very important:

REASON WHY IT IS IMPORTANT TO MONITOR AND REVIEW YOUR HAZARD CONTROL PROGRAM AND METHODS?

It is important to monitor both the hazard and the control methods adopted to make sure that the control is working effectively and that exposure to the hazard is reduced or eliminated.

Some tools include physical inspection, testing, exposure assessment, observations, injury and illness tracking, accident/incident investigations reports, employee feedback/input, occupational health assessment and other methods.

Be sure to answer the following questions:

• Have the controls solved the problem?
• Is the risk posed by the original hazard contained?
• Have any new hazards been created?
• Are new hazards appropriately controlled?
• Are monitoring processes adequate?
• Have workers been adequately informed about the situation?
• Have orientation and training programs been modified to deal with the new situation?
• Are any other measures required?
• Has the effectiveness of hazard controls been documented in your committee minutes?
• What else can be done?

Adapted from the Occupational Health and Safety Committee Manual.