International Labor Organization handbook is designed to help provide information and training for inspectors. It contains information on key safety and health concepts and occupational safety and health issues, including managing an inspection program and performing on-site inspections.
Section 7: OSH hazards/risks on construction sites
7.1 General principles of prevention
7.2 The main OSH hazards/risks in the construction industry
The general principle for minimizing OSH hazards/risks is:
to identify/know the hazards/risks involved, to analyse them and consequently avoid or prevent them.
This principle should be applied to each of the basic resources (labour, material and equipment) and to each construction operation, construction element and construction project as a whole. In many countries (e.g. the European Union countries), this procedure is known as the application of the “general principles of prevention” during the design phase and during the execution phase. These principles are presented and briefly described with examples in subsection 7.1 of this document.
It is important to know the main occupational safety and health hazards/risks in the construction industry and these are presented in subsection 7.2. This will allow all those who have to take the preventive measures (those involved directly in the construction process) or to inspect the measures taken (labour inspectors, but also the OSH experts on behalf of other interested parties), to pay special attention and give priority to these hazards/risks.
In the European Union, the nine “General Principles of Prevention” (GPP) are: (1) Avoid risks; (2) Evaluate the risks which cannot be avoided; (3) Combat the risks at source; (4) Adapt the work to the individual, especially as regards the design of work places, the choice of work equipment and the choice of working and production methods, with a view, in particular, to alleviating monotonous work and work at a predetermined work-rate and to reducing their effect on health; (5) Adapt to technical progress; (6) Replace the dangerous by the non-dangerous or the less dangerous; (7) Develop a coherent overall prevention policy which covers technology, organization of work, working conditions, social relationships and the influence of factors related to the working environment; (8) Give collective protective measures priority over individual protective measures; (9) Give appropriate instructions to the workers.
These are also shown in table 8 together with some comments on or examples of each. Compliance with these GPP is of utmost importance for safety and health during the design and construction phases. They should be applied by the designers during the design process and by the contractors during the construction process, and be followed up by those who have to monitor the prevention measures (project supervisors, OSH coordinators and experts, etc.).
|1. Avoid risks
To avoid risks of falls on a building project, consider the execution of scaffolding as the building grows in height; consider planning the project by avoiding simultaneous and incompatible construction operations (worker distractions are responsible for many occupational accidents); carefully consider the appropriate period of time to be allotted for the performance of the different tasks to minimize the pressure that might otherwise accompany an unrealistic work goal; …
|2. Evaluate the risks
which cannot be avoided Consider the preparation of Inspection and Monitoring Plans for all relevant construction operations in terms of risks involved; consider the technical maintenance, pre-commissioning checks and regular checks on installations and equipment with the objective of correcting any faults which might affect the safety and health of workers; …
|3. Combat the risks at source
Consider ways of confining and neutralizing the risk at the source; avoid the use of noisy equipment by selecting equipment that has been engineered to generate less noise; consider also the sound-proofing of the engine ’s compartment; consider air conditioning in the driver compartment on earthmoving equipment so that the work can be performed with closed windows without exposing the driver to noise and other environmental hazards as dust and fumes; …
|4. Adapt the work to the individual, especially as regards the design of work places, the choice of work equipment and the choice of working and production methods, with a view, in particular, to alleviating monotonous work and work at a predetermined work-rate and to reducing their effect on health
To reduce hazards consider the use of ergonomic equipment and perform risk analysis when choosing equipment and construction processes and methods; avoid undue pressure in project scheduling, by accurately allotting adequate time to perform each construction operation; perform regular health inspections of workers;...
|5. Adapt to technical progress
Use only certificated equipment according to the regulations and standards; prepare a procedure to organize a database on all relevant regulations and standards and keep the database current by including all recent changes; implement the procedures to avoid the non intentional use of obsolete technical documents; …
|6. Replace the dangerous by the non-dangerous or the less dangerous
Reduce hazards by using vegetal based oil for forms instead of dangerous oils; replace materials based on dangerous asbestos with other equivalent and non dangerous materials; be aware of the conditions under which the hazardous materials are to be removed (e.g. existing dangerous asbestos); consider the demarcation and laying-out of areas for the storage of various materials, in particular where dangerous materials or substances are concerned; plan the storage and disposal or removal of waste and debris; …
|7. Develop a coherent overall prevention policy which covers technology, organization of work, working conditions, social relationships and the influence of factors related to the working environment
Consider a formal safety and health (prevention) policy provided by each Contractor on site; assure the cooperation between employers and self-employed persons; consider the interaction with industrial activities at the place within which or in the vicinity of which the construction site is located; choose the location of workstations bearing in mind how access to these workplaces is obtained, and determine ways or areas for the passage and movement of equipment; keep the construction site in good order and in a satisfactory state of cleanliness; consider the conditions under which various materials are handled; implement periodic safety and health audits and inspections; …
|8. Give collective protective measures priority over individual protective measures
Consider, for example, guardrails for fall protection, where needed, and complementary safety nets and/or life lines with safety harnesses (together with all other personal protective equipment that are mandatory, including hardhats and safety shoes); use the appropriate shoring systems or slope the walls of excavations, whenever the soil is not pure rock; …
|9. Give appropriate instructions to the workers
Instructions should be simple and only as detailed as needed; consider visual communications; consider different languages for these instructions according to the origin of workers on site, and promote safety and health meetings; …
In some cases, the GPP should be included in the specifications as mandatory, so that all designers and contractors will follow them in the tendering processes. These stakeholders must know, understand and interpret these principles in the light of the design and the construction process and working methods for each project.
In general terms, the application of these general principles of prevention, during both design and execution phases, is based on the following question for each construction project and each major construction element (taking into consideration different possible or alternative architectural, technical or organizational solutions):
How will it be built and maintained?
For each construction project (a building, a bridge, a road, etc.), this question can be expanded in different ways as in the following examples:
- How will each construction element be built without putting workers into a dangerous situation that might compromise their safety and health? Is there any other solution which is less dangerous and does not compromise the architectural or technical requirements?
- How will this construction element be maintained during the life of the construction project, without putting the maintenance workers at risk? How will the façade be cleaned (for example, windows may be cleaned from the inside or should a platform be installed on the outside)?
- How will maintenance workers get access to equipment if it is placed in a particular position (for example, air conditioning equipment placed very high)?
- How will access be provided to the roof of the building (bearing in mind the slope as well)? For future maintenance, should some points of anchorage be left in place to accommodate “life lines” and safety harnesses, or to attach platforms on the ridge of the roof? Could the parapet on the roof be 1,00 - 1,20 metres high to avoid the need for temporary guardrails (ensuring that the workers of both the execution and maintenance phases work safely on the roof)?
These are just some of the questions that should be always kept in mind, especially by designers, contractors and their OSH experts , as well as by the project supervisors and the OSH experts/coordinators appointed by the owner of the construction project (during both the design and execution phases).
OSH concerns the whole life of the construction project (from the very early stages of design until the demolition). Accordingly, the Safety and Health Plan deals with the OSH of the workers involved during the execution phase and the Safety and Health File deals with the OSH of the workers involved during the maintenance period (both documents are referred to in subsection 9.1).
OSH should be guarantee in all construction projects, but the requirements should take into account their size (based on estimated project cost and/or person-days), complexity and whether the works involve particular risks as defined in the law of many countries.
Types of work involving particular risks as defined by the Construction Sites Directive (92/57/EC, 1992) of the European Union are: (1) Work which puts workers at risk of burial under earth falls, engulfment in swampland or falling from a height, where the risk is particularly aggravated by the nature of the work or processes used or by the environment at the place of work or site; (2) Work which puts workers at risk from chemical or biological substances constituting a particular danger to the safety and health of workers or involving a legal requirement for health monitoring; (3) Work with ionizing radiation requiring the designation of controlled or supervised areas; (4) Work near high voltage power lines; (5) Work exposing workers to the risk of drowning; (6) Work on wells, underground earthworks and tunnels; (7) Work carried out by drivers having a system of air supply; (8) Work carried out by workers in caisson with a compressed-air atmosphere; (9) Work involving the use of explosives; (10) Work involving the assembly or dismantling of heavy prefabricated components.
However, related to the first group of works involving particular risks referred to in above, it does not seems reasonable, for example, to consider as “involving particular risks” all risks of falling independently of the working height or all excavations independently of the working depth.
Actually, the mentioned EU Directive gives each country the option of setting figures for individual situations and indeed some countries have taken it up. For risk of burial under earth falls, some countries consider a depth of more than 1,20 metres while others consider 1,50 metres. As for the risk of falling from height, some figures set this at 2 metres, some at 3 metres or at 5 metres.
Some countries again have set figures for other work involving particular risk, as for example the demolition or deconstruction work involving more than 200 cubic metres of the product to be removed from the construction site, and work involving lifting equipment with a capacity over 60 tons-meter (e.g. mobile or tower cranes).
The most frequent hazards/risks in the construction industry fall into two main categories (Figure 20):
a) hazards/risks that may cause occupational accidents, sometimes fatal, immediately or soonafter they occur;
b) hazards/risks that may cause occupational illness, sometimes also fatal, in the medium or long term (from a few hours to many years later).
The leading accident hazards/risks in the construction industry in most countries are:
- Falls from height (from unguarded floors, platforms, scaffoldings, roofs, etc.);
- Caught in/between (malfunction of machinery, etc.);
- Cave in (malfunction of the shoring system, sloping missing in excavations, etc.);
- Electrocution (by contact with power lines, power tools, etc.); and
- Struck by (falling objects, etc.).
The leading occupational illnesses hazards/risks in the construction industry in most countries are:
- Back injuries (from carrying heavy loads, working in inappropriate positions, etc.);
- Respiratory diseases (from inhaling dust, fumes, etc.);
- Musculoskeletal disorders (from sprains and strains of the muscles, injuries affecting the hand and wrist, the shoulders, neck and upper back, the knees, etc.);
- Hearing losses (from long time exposure to noise); and
- Skin diseases (manipulation of dangerous materials, exposure to the ultraviolet rays).
Many other potential hazards/risks in the construction industry depend on the type of construction works (buildings, bridges, etc.). Table 9 gives a non-exhaustive list of hazards/risks in the construction industry. It can be used to identify and record the main hazards/risks that may occur in a specific construction project by checking “yes”, “no” or “NA” (not applicable). It may also be used to record the risk level (RL) by estimating a probability (P) of occurrence and a severity (S).
|Hazards/Risks||Exists?||Risk Level (RL)||Notes / Comments
(e.g. where the risks may occur, exposure period, temperature, etc.)
|1.1. Falls from height|
|1.2. Falls at the same level|
|1.3. Fall of objects|
|1.4. Struck between|
|1.5. Cave in|
|1.6. Running over|
|1.7. Collision of vehicles|
|1.9. Crushing of the foot|
|1.10. Fall for slipping|
|1.11. Pointed or cutting objects|
|1.12. Foot torsion (irregular floor)|
|1.13. Shock at the malleolus level|
|1.14. Shock at the metatarsus level|
|1.15. Shock at the leg level|
|1.16. Shock with fixed objects|
|1.18. Hits on the head|
|1.22. Hold by rotary parts|
|2.1. Electric shock|
|2.2. Electrostatic discharges|
|3.5. Projection of metals in fusing|
|4.1. Ultraviolet radiations|
|4.2. Radiations infra-red ray|
|4.3. Solar radiations|
|4.4. Ionizing radiations|
|Hazards/Risks||Exists?||Risk Level (RL)||Notes / Comments
(e.g. where the risks may occur, exposure period, temperature, etc.)
|4.5. Laser rays|
|5.1. Exposure to noise|
|6.3. Gases or vapours|
|6.4. Toxic or corrosive products|
|6.5. Corrosive liquids|
|7.1. Pathogenic material|
|8. Other hazards/risks|
|8.2. Intemperate weather|
|8.3. Confined space|
|8.4. Low visibility|
|9. Hazards/risks affecting health|
|9.1. Back injuries|
|9.2. Respiratory diseases|
|9.3. Musculoskeletal disorders|
|9.4. Hearing losses|
|9.5. Skin diseases|