General Hierarchy Of Control Measures

General Hierarchy Of Control Measures

Hierarchy of Control 

A hierarchy of control should be considered when assessing the adequacy of existing controls or introducing new controls. The principles of prevention in the MHSW Regulations 1999 are not a hierarchy but a list of prevention principles that must be considered when controlling risks. However, a preferred hierarchy of control follows these principles and those in HSG65. The 2006 NEBOSH General Certificate syllabus uses the same hierarchy with minor differences. These are shown in Table.

Hierarchy Of Control Measures

The hierarchy reflects risk elimination and control by using physical engineering controls, and safeguards can be more reliably maintained than those relying solely on people. These concepts are now written into the Control of Substances Hazardous to Health (COSHH) Regulations and the Management of Health and Safety at Work (MHSW) Regulations.

Where a range of control measures are available, it will be necessary to weigh up the relative costs of each against the degree of control each provides, both in the short and long term. Some control measures, such as eliminating risk by choosing a safer alternative substance or machine, provide reliable control. Physical safeguards such as guarding a machine or enclosing a hazardous process must be maintained. In making decisions about risk control, it will be necessary to consider the degree of control, the reliability of the control measures, and the costs of providing and maintaining the measure.

Avoidance of risks by elimination or substitution

The best and most effective way of reducing risks is by avoiding a hazard and its associated risks. For example, avoid working at height by installing a permanent working platform with stair access; avoid entry into a confined space by, for example, using a sump pump in a pit that is removed by a lanyard for maintenance; eliminate the fire risks from tar boilers by using bitumen which can be applied cold. 

Substitution describes using a less hazardous form of a substance or process. There are many examples of substitution, such as water-based rather than oil-based paints, asbestos substitutes, and compressed air as a power source rather than electricity, to reduce electrical and fire risks using mechanical excavators instead of hand digging. 

Sometimes, it is possible to change the working method to reduce risks. For example, use rods to clear drains instead of strong chemicals; use a long-handled water hose brush to clean windows instead of ladders. Sometimes, the work pattern can be changed so people can do things more naturally. For example, when placing components for packing, consider whether people are right- or left-handed; encourage people in offices to take breaks from computer screens by getting up to photocopy, fetch files or print documents.

Care must consider any additional hazards and introduce additional risks resulting from a substitution. 

Reduced time exposure

This involves reducing the employee’s time exposed to the hazard during the working day by giving the employee other work or rest periods. It is normally only suitable for controlling health hazards such as noise, vibration, excessive heat or cold, display screens and hazardous substances. However, it is important to note that there are short-term exposure limits and normal workplace exposure limits (WELs) over 8 hours for many hazards. Short-term limits must not be exceeded during the reduced time exposure intervals. 

It cannot be argued that a short time of exposure to a dangerous part of a machine is acceptable. However, it is possible to consider short bouts of intensive work with rest periods when employees are engaged in heavy labour, such as manual digging when machines are not permitted due to the confines of the space or buried services. 


Controlling risks by isolating them or segregating people and the hazard is an effective control measure and is used in many instances; for example, separating vehicles and pedestrians on factory sites, providing separate walkways for the public on road repairs, providing warm rooms in areas or noise refuges in noisy processes. 

The isolation principle is usually followed by storing highly flammable liquids or gases put into open, air-ventilated compounds away from other hazards such as ignition sources or from people who may be at risk from fire or explosion. 

Engineering controls

This describes the control of risks by means of engineering design rather than relying on the employee’s preventative actions. There are several ways of achieving such controls:

1. Control the risks at the source (e.g., using more efficient dust filters or purchasing less noisy equipment). 

2. Control the risk of exposure by: 

  • isolating the equipment by the use of an enclosure, a barrier or guard; 
  • insulating any electrical or temperature hazard; 
  • ventilating away any hazardous fumes or gases either naturally or by the use of extractor fans and hoods

Safe systems of work

Operating procedures or safe systems of work are probably the most common form of control measure used in industry today and maybe the most economical and, in some cases, the only practical way of managing a particular risk. They should allow for the methodical execution of tasks. The development of safe operating procedures should address the hazards identified in the risk assessment. The work system describes the safe method of performing the job or activity. A safe system of work is a requirement of the Health and Safety at Work Act and is dealt with in detail later. 

If the risks involved in the task are high or medium, the details of the system should be in writing and should be communicated to the employee formally in a training session. Details of systems for low-risk activities may be conveyed verbally. There should be records that the employee (or contractor) has been trained or instructed in the safe system of work and that they understand it and will abide by it. 


Training helps people acquire the skills, knowledge and attitudes to make them competent in their work’s health and safety aspects. There are generally two types of safety training: 

  • Specific safety training (or on-the-job training) aims at tasks where training is needed due to the specific nature of such tasks. This is usually a job for supervisors, who, by their authority and close daily contact, are in a position to convert safety generalities to the everyday safe practice procedures that apply to individual tasks, machines, tools and processes; 
  • Planned training, such as general safety training, induction training, management training, skill training, or refresher courses that the organization plans and relates to managing risk through policy, legislative or organizational requirements common to all employees.

Before any employee can work safely, they must be shown safe procedures for completing their tasks. Safety training should improve employees’ safety awareness and show them how to perform their jobs by employing acceptable safe behaviour.


Organizations need to ensure that they have effective arrangements for identifying and receiving relevant health and safety information from outside the organization, including: 

  • ensuring that pertinent health and safety information is communicated to all people in the organization who need it; 
  • ensuring that relevant information is communicated to people outside the organization who require it; 
  • encouraging feedback and suggestions from employees on health and safety matters. 

Anyone affected by what is happening in the workplace will need to be given safety information. This does not only apply to staff. It can also apply to visitors, members of the public and contractors.

Information to be provided for people in a workplace include: 

  • who is at risk and why; 
  • how to carry out specific tasks safely; 
  • correct operation of equipment; 
  • emergency action; 
  • accident and hazard reporting procedures; 
  • the safety responsibilities of individual people. 

Information can be provided in a variety of ways. These include safety signs, posters, newsletters, memos, emails, personal briefings, meetings, toolbox talks, formal training, written safe systems of work and written health and safety arrangements.

Safety signs

All general health and safety signs used in the workplace must include a pictorial symbol categorized by shape, colour and graphic image.

All workplaces need to display safety signs of some kind but deciding what is required can be confusing. Here are the basic requirements for the majority of small premises or sites like small construction sites, canteens, shops, small workshop units and offices. This does not cover any signs that food hygiene law may require. 

Most requirements are covered by the Health and Safety (Safety Signs and Signals) Regulations 1996. These require signs wherever a risk has not been controlled by other means. For example, if a wet floor area is cordoned off, a warning sign will not be needed because the barrier will keep people out of the danger area. Signs are not needed where the sign would not reduce the risk, or the risk is insignificant. 

Colour categories and shapes of signs

The following signs are typical of some of the most likely needed on these premises. Others may be necessary, depending on the hazards and risks present. 

  • Overhead obstacles, construction site and Prohibition notices.
  • (Wet floors These need to be used wherever a slippery area is not cordoned off. Lightweight stands holding double-sided signs are readily available
  • Chemical storage Where hazardous cleaning chemicals are stored, apart from keeping the store locked, a timely warning notice should be posted if it is considered this would help to reduce the risk of injury. 
  • Fire safety signs The Regulations apply in relation to general fire precautions. The guidance under the Fire Safety Order requires signs to comply with BS5499-4 and 5 and the Safety Signs and Signals Regulations. Since 24 December 1998, the older, text-only ‘fire exit’ signs should have been supplemented or replaced with pictogram signs. Fire safety signs complying with BS5499-4 and 5 already contain a pictogram and do not require changing. 
  • Fire action signs These and other fire safety signs, such as fire extinguisher location signs, will be needed. 
  • First aid Signs showing the location of first first-aid facilities will be needed. Advice on the action to take in the case of electric shock is no longer a legal requirement but is recommended.
4 Examples of warning, mandatory and prohibition signs.
  • Gas pipes and LPG cylinder stores should have the sign.
  • No smoking
Smokefree – no-smoking sign.

Fragile roofs

Fragile roofs Signs

Signs should be erected at roof access points and at the top of outside walls where ladders may be placed.

  • Obstacles or dangerous locations, For example, low head height, tripping hazard, etc. – alternating yellow and black stripes.
  • Other signs and posters 

Health and safety law – What you should know (there is a legal requirement to display this poster or distribute an equivalent leaflet). 

Certificate of Employer’s Liability Insurance (there is a legal requirement to display this). 

Scalds and burns are common in kitchens. A poster showing recommended action is advisable, for example, ‘First Aid for Burns’. 

  • Sign checklist 
Safety Signs at Work

Existing signs should be checked to ensure that: 

  • they are correct and up to date; 
  • they carry the correct warning symbol where appropriate; 
  • they are relevant to the hazard; 
  • they are easily understood; 
  • they are suitably located and not obscured; 
  • they are clean, durable and weatherproof where necessary; 
  • illuminated signs have regular lamp checks; 
  • they are used when required (e.g. ‘Caution wet floor’ signs); 
  • They are obeyed and effective.

Personal protective equipment

Personal protective equipment (PPE) should only be used last resort. There are many reasons for this. The most important limitations are that PPE:

  • only protects the person wearing the equipment, not others nearby; 
  • relies on people wearing the equipment at all times; 
  • must be used properly; 
  • It must be replaced when it no longer offers the correct level of protection. This last point is particularly relevant when respiratory protection is used. 

The benefits of PPE are: 

  • it gives immediate protection to allow a job to continue while engineering controls are put in place; 
  • in an emergency, it can be the only practicable way of effecting rescue or shutting down the plant in hazardous atmospheres; 
  • it can be used to work in confined spaces where alternatives are impracticable. But it should never be used to allow people to work in dangerous atmospheres, for example, enriched with oxygen or potentially explosive. 


Welfare facilities include general workplace ventilation, lighting and heating, drinking water, sanitation, and washing facilities. There is also a requirement to provide eating and restrooms. Risk control may be enhanced by providing eye washing and shower facilities after certain accidents.

Good housekeeping is a very cheap and effective means of controlling risks. It involves keeping the workplace clean and tidy and maintaining good storage systems for hazardous substances and other potentially dangerous items. The risks most likely to be influenced by good housekeeping are fire and slips, trips and falls. 

Monitoring and supervision

Whether they rely on engineered or human behavioural controls, all risk control measures must be monitored for their effectiveness with supervision to ensure that they have been applied correctly. Competent people with sound knowledge of the equipment or process should undertake monitoring. Checklists are useful to ensure that no significant factor is forgotten. Any statutory inspection or insurance company reports should be checked to see whether any areas of concern were highlighted and if any recommendations were implemented. Details of any accidents, illnesses or other incidents will indicate the effectiveness of the risk control measures. Any emergency arrangements should be tested during the monitoring phase, including first-aid provisions. 

The operator must be monitored to ascertain that all relevant procedures have been understood and followed. The operator may also be able to suggest improvements to the equipment or system of work. The supervisor is an important source of information during the monitoring process. 

Where the organization is involved with shift work, the risk controls must be monitored on all shifts to ensure uniformity of application. 

The effectiveness and relevance of any training or instruction given should be monitored. 

Periodically the risk control measures should be reviewed. Monitoring and other reports are crucial for the review to be useful. Reviews often occur at the safety committee and/or at management meetings. A serious accident or incident should lead to an immediate review of the risk control measures in place. 

Similar Posts


Leave a Reply

Your email address will not be published. Required fields are marked *