Hierarchy of hazard control OHS-403

Introduction to Hierarchies of Control The concept of a hierarchy of control strategies underpins OHS legislation and most workplace control actions. Originally developed for occupational hygiene applications, the hierarchy of control establishes the priority order in which hazard and risk controls should be considered. When applied in the broader OHS context, the hierarchy of control is a problem-solving tool to promote creative thinking when developing options for risk control rather than a fixed set of rules. Introduction to Hierarchies of Control

Figure 1 is one representation of a hierarchy of control that highlights the relative protection and reliability of controls Hierarchy of control

Elimination – Remove the cause of danger completely Substitution- Controls the hazard by replacing it with a less risky way to achieve the same outcome. Isolation- Separates the hazard from the people at risk by isolating it Engineering- Using Engineering controls, i.e. making physical changes, to lessen any remaining risk. Example redesign a machine by adding safeguards. Administration- Use administrative controls to lessen the risk . Example install signs, rotate workers Personal Protective equipment- Require your employees to wear PPE. Example provide gloves, ear plug, goggles Use of Personal protective equipment to control hazards always be the last resort.

Hierarchy of hazard controls Traditional hierarchy of control works reasonably well for separate physical risks such as plant or hazardous chemicals; however, it is not suitable to all risks, particularly psychosocial risks. In addition, the hierarchy has been abused by oversimplification. In any situation where control is imposed, particularly where elimination or substitution is involved, the potential or unintended consequences must be considered. For example, elimination of human involvement as a result of automation may change the basis for risk assessment in a fundamental way, and it is not appropriate to claim that such ‘elimination’ reduces risk unless the short-term and long-term consequences are fully taken into account. Indeed, automation introduces a different range of risks that were not considered in the original risk assessment and therefore necessitates a new assessment. Hierarchy of hazard controls

Safety through Elimination Although prevention in many ways is better than protection, it is a fact of life that perfect prevention is impossible.  In order to ensure safety by preventing something from happening, i.e., through the elimination of risks, it is first of all necessary that the risks are known or can be made known.  The pursuit of safety through the elimination of risks also required that the specific risk source actually can be removed from the system without impeding or changing the system’s functioning. In some cases, this condition is obviously violated as when the elimination of a risk means the loss of a primary function. Thus, the risk of an airplane falling down can only be fully eliminated by not taking to the air, but that is clearly not a viable option, at least in commercial aviation.  Simple example is an elimination of noisy machinery from workplace or eliminating the use of hazardous chemical or plant Safety through Elimination

Safety through Substitution Elimination by means of substitution is an often used solution, the most conspicuous case being when human performance is replaced by technology, specifically by automation. The rationale for this is that automation is highly reliable because it is the result of a formal design process and because it is based on components with known failure rates. Humans, on the other hand, are generally seen as fallible and unreliable, as ‘proved’ by countless examples of ‘human error’. Safety through Substitution

Safety through substitution Human Vs Automation Ladder Vs Scaffolds Safety through substitution

Safety through Isolation Isolation is the third most effective means of controlling hazard. Isolation control ,separates the hazard from people at risk by isolating it. This involves physically separating the source of harm from people by distance or using barriers. Example install guard rails around exposed edges and holes in floors, use remote control system to operate machinery , store chemicals in a fume cabinet Safety through Isolation

Safety through isolation Edge protection to control falling hazard Offshore plants and chemical companies are generally kept away from general public because of their hazardous nature Safety through isolation

Safety through Isolation Isolation through distance Isolation through barrier Safety through Isolation

Safety through Isolation Using chemicals in fume hoods Explosion proof panels Safety through Isolation

Engineering control is the fourth most effective means of controlling hazard. Capital costs of engineering controls tend to be higher than those the less effective controls within the hierarchy, however they may reduce the future costs. Enclosure or isolation “ creates a physical barrier between a person and hazard. example- Remotely controlled equipment, exhaust ventilation, providing physical guards and design modification and alteration. Engineering control

Safety through Engineering control

Administration or administrative controls Administrative controls are changes to the way people work example Procedure changes Employee training Installation of signs and warning labels Administrative controls do not remove hazards, rather limit or prevent people’s exposure to the hazards, such as completing road construction at night when fewer people will be driving. Administration or administrative controls

Example of administrative controls Scheduling maintenance and other high exposure operations for times when few workers are present ( Such as evening or 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. Example of administrative controls

Administrative controls Work practices Even where there are well designed and maintained engineering controls, 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. Keeping equipment well maintained. Preparing and training for emergency response for incidents such as spills, fire for employee injury Administrative controls

Administrative controls 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 of their job. It must also provide them with information on how to protect them selves and co-workers. Administrative controls

Personal Protective equipment PPE is the least effective way to control hazards. PPE can include gloves, respirators, hard hats, safety glasses, high visibility clothing, and safety footwear. PPE is the least effective means of controlling hazards because of the high potential for the PPE to become ineffective due to damage. Some PPE, such as respirators, increase physiological efforts to complete a task and, therefore, requires medical examinations to ensure the worker can use the PPE without risk to his or her own health Personal Protective equipment

PPE as a hazard control method It is the for a 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 without warning. PPE as a hazard control method

Monitor and review hazard control program and methods It is important to monitor both the hazard and the control method 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, employee feedback/ input, occupational health assessment and other methods. Monitor and review hazard control program and methods

Example of application of hierarchy of controls to hazard Overexposure to Noisy Generators Example Eliminate the use of Noisy generator, If it is not possible Substitute or replace with new model of generator with insulating material which emits less noise. Isolate the use of generator away from employees or normal public. Engineering control -Provide insulation or acoustic material Administrative control- Educate employees regarding noise hazard, provision of signs and labels, monitor noise level and check employees exposure to noise PPE- Provide ear plugs or ear Muff to employees. Example of application of hierarchy of controls to hazard

Heat stress in Foundry's We can not eliminate heat sources as those are required for primary function for iron melting, and casting. Isolate- We can isolate employees from hot process equipment or reduce the exposure by providing AC control rooms Engineering controls- Design the process such a way that exposure of employees would be limited. Providing natural ventilation or Mechanical ventilation. Administrative control measure- Training to employees regarding heat hazards or process and necessary controls. Signs, medical tests, provision of cold water, job rotation PPE-Provision of light and cotton cloths Hazard and control

Road accidents are increasing every day Road accidents are increasing every day. Suggest various controls to avoid these road accidents. Recognize 10 engineering and administrative controls which are used in university campus. Tutorial-2