UNIT 7: SAFETY 7.1 SAFETY CONTROL 7.2 SAFETY MANAGEMENT 7.3 GROUNDWORKS SAFETY MANAGEMENT 7.4 BASIC PROCEDURES IN THE EVENT OF AN ACCIDENT
Safety is of paramount importance as any failure can result in very large costs to the project and Organisation. In worst cases, failures may cause personal injuries or fatalities. Indirect costs of insurance, inspection and regulation are increasing rapidly due to increased direct costs. Another possible delay (and cost) is a Stop Work Order imposed by Authorities. Safety during construction is influenced by decisions made during the planning and design process. Some designs or construction plans are inherently difficult and dangerous to implement. Beyond these design decisions, safety largely depends upon education, vigilance and cooperation during construction process.
Liability on Contractors. Construction is a relatively hazardous undertaking. There are significantly more injuries and lost mandays in construction than in any other industry. These work related injuries and illness are exceedingly costly. Sometimes innocent bystanders may also be injured by construction accidents. Several crane collapses from high rise buildings under construction have resulted in fatalities to passer-by. Prudent Project Managers and clients would like to reduce accidents, injuries and illness as much as possible.
While contractors may pay insurance premium directly, these costs are reflected in bid prices or contract amounts. Delays caused by injuries and illness can present significant opportunity costs to the clients. The causes of injuries are numerous. The largest single category is falls (fall from height). Handling goods and transportation are also a significant cause of injuries. Yet another common injury is hit by falling objects. The reasons may be varied for eg an individual fall may be due a railing not being secured and the worker was inattentive or the footing may be slippery.
Various measures are available to improve safety in construction. Some are taken even before commencement of construction, like design, choice of technology and education. By changing certain designs, certain structures may either be safer or more hazardous to build. Choice of technology can also be critical in determining the safety at work. Safeguards built into machinery can notify operators of problems or prevent injuries. For eg simple switches can prevent equipment from being operated when protective shields are not in place; or passenger hoists cannot be operated when landing doors are not close.
Education for both workers and supervisory (including managers) are also important. The realization of large costs involved in construction injuries and illnesses provides a considerable motivation for awareness and education. Regular safety inspections and meetings have become standard practices on most job sites. Pre-qualification of contractors and subcontractors with regard to safety is another avenue for safety improvement. During construction, vigilance and cooperation on the part of managers, inspectors and workers is most important. Vigilance and inspections will also help maintain temporary physical safeguards like barricades, braces, toe boards, railings etc
Other standard site practices such as mandatory wearing of Personal Protective Equipment (PPE) whenever one is within site boundary, also helps to prevent accidents. Yet another rule is the compulsory wearing of safety harness when working at height. While most organisations and sites are targeting zero accidents, it is a difficult task considering the hazardous nature of construction. The jobsite is continually changing as construction proceeds. Workers are sometimes deployed to different worksites and their familiarity to the surroundings are always challenged. Despite these problems, improving worksite safety is a very important project management concern.
7.2 Safety Management Construction sites are developmental in nature and so the conditions are changing all the time. Hence it is important to ensure that all those working are kept aware of the changes and potential dangers. There are many ways to undertake this: > Inductions is the process which occur when a new worker (or staff) arrives at site. He attends a short talk when all the perceived risks at site are explained together with all the site rules and obligations on he individual to ensure the safety of others.
> Tool- box talks are undertaken in the morning before work commencement or during tea-breaks. They are used to update all the workers on safety when new or unexpected conditions arise, or potential dangers of the new task to be undertaken for that day. > Training is likely to be project specific and will take place either on site or at a training centre. This will be provided for the workforce and will likely include theoretical and practical eg erecting scaffold towers or confined space training for working in sewers.
> Inspections are critical for safety management and some are requirements under Health and Safety Legislation. For eg scaffolds have several differing inspections obligations ranging from weekly routine to post storm inspections, all should be recorded and properly tagged to inform if it is safe for use. > Reviews should be undertaken regularly by independent (head office) personnel either senior managers or in larger organisations by corporate safety. > Risk assessments are important especially at the start of new site activities. Every element of the work is assessed for risk and in the event of high risk, a method statement is required dictating the way in which a safe method of working will be achieved.
Method Statements are supported by different elements of legislation including COSHH regulations (for hazardous substances), PPE regulations (helmets, vest, boots etc), working at height regulations. These will help in the development of safe methods of working. Equally important is the need for these statements to be communicated to the workers. Documentation is required to provide evidence to inspectors (government or internal) that all reasonable and practicable steps are being taken to protect the workforce. Standard forms are available of all statutory inspections and these must be routinely completed to record the actions undertaken.
7.3 Groundworks Safety Management Some competent and professional site safety practices covering temporary ground works are as follows: > Competent person should have and able to demonstrate the following: *Training, experience and knowledge of soil analysis and use of protective systems. *Ability to detect conditions that could result in cave-ins, failures in protective systems, hazardous atmospheres and others associated with confined spaces. *Authority to take prompt corrective measures to eliminate existing and predictable hazards and to stop work when required.
> Surface crossing of trenches should be discouraged; however if trenches must be crossed, it may only be permitted under the following conditions: * Vehicle crossings must be designed by and installed under the supervision of a registered professional engineer. * Walkways or bridges must be provided for pedestrian. * Have a minimum clear width of 20 in (0.51m) and be fitted with standard rails and extend a minimum of 24 in (0.61m) past the surface edge of the trench. * All crossings shall have a safety factor of 4.
> Ingress and Egress Access to and exit from the trench must fulfill the following conditions: * Trenches 4 ft or more in depth should be provided with a fixed means of egress. * Spacing between ladders or other means of egress should not be more than 25 ft laterally to the nearest means of egress. * Ladders must be secured and extend a minimum of 36 in above the landing. * Metal ladders should be used with caution particularly when electric utilities are present. * Hand rails must be provided for all ladders
> Exposure to vehicles procedures to protect employees from being injured or killed by vehicle traffic include: * Providing employees with and requiring them to wear warning vests or other suitable garments marked with or made of reflectorized or high visibility materials. * Requiring a designated, trained flag person along with signs, signals and barricades when necessary. * Identify designated traffic routing.
> Exposure to falling loads Employees must be protected from loads or objects falling from lifting or digging equipment. Procedure designed to ensure their protection include: * Employees are not permitted to work under raised loads. * Employees are required to stand away from equipment that is being loaded or unloaded. * Equipment operators or truck drivers may stay in their equipment during loading and unloading if the equipment is properly equipped with a cab shield or adequate canopy.
> Warning system for mobile equipment and vehicles: The following should be taken to prevent vehicles from accidentally falling into trenches: * Barricades must be installed where necessary * Hand or mechanical signals must be used as required. * Stop logs or wedges must be used if there is a danger of the vehicles falling into the trench * Soil should be graded away from the excavation enhancing vehicle control and channeling of run-off water.
> Hazardous atmospheres and confined spaces Employees are not allowed to work in hazardous and /or toxic atmospheres including those with: * Less than 19.5% or more than 23.5% oxygen; * A combustible gas concentration greater than 20% of the lower flammable limit; * Concentrations of hazardous substances that exceed those specified in the Threshold Limit Values for Airborne Contaminants established by American Conference of Governmental Industrial Hygienists or as per relevant local statutory codes. * Tests for atmospheric contaminants should be conducted before employees enter the trench and should be done regularly to ensure its safety. Frequency should be increased if equipment is operating in the trench as with the presence of hot-works such as welding, cutting or burning.
> Emergency Rescue Equipment is required when a hazardous atmosphere exists or can reasonably be expected to exist. Some trenches qualify as confined spaces. When this occur the following requirements are to be complied: * Respirators must be of the type suitable for exposure. * Attended (at all times) lifelines must be provided when employees enter bell-bottom pier holes, deep confined spaces or similar hazards. * Employees required to wear respiratory protection must be trained, fit tested and enrolled in a respiratory protection program.
> Standing water and water accumulation Methods to control standing water and water accumulation must be provided and should consist of the following if employees are permitted to work in the excavation: * Use of a special support or shield systems approved by a registered professional engineer. * Water removal equipment and methods (e,g well pointing) used and monitored by a competent person. * Safety harness and lifelines used in conformance with safety regulations. * Surface water diverted away from the trench
* Operatives evacuated from the trench during rainstorms. * Trenches carefully inspected by a competent person after each rain and before operatives re-enter.
> Inspections shall be made by a competent person and should be documented. The following guide specifies the frequency and conditions requiring inspections: * Daily and prior to the start of each shift. * As dictated by the work being done in the trench. * After every rainstorm. * After other events that could increase the hazards e.g snowstorm, windstorm, thaw, earthquake etc * When fissures, tension cracks, sloughing, undercutting, water seepage, bulging or other similar conditions occur. *When there is a change in the size, location or placement of spoil pile. * When there is any indication of change or movement in adjacent structures.
7.4 Basic Procedure in the Event of an Accident The WSH ( Incident Reporting) Regulations set the requirement for reporting workrelated accidents, occupational disease and dangerous occurrences to the Ministry. Employers also report accidents and occupational diseases for compensation purposes under the WIC Act. Reports are submitted to the Ministry via an online reporting system known as ireport. The database of the accidents and incidents reported is analysed by OSHD to identify the trends in WSH and identify hot spot areas for intervention.
In addition a WSH hotline is available for members of the public and workers to report on unsafe work practices and conditions. Duty to notify and report an accident leading to death. 1) Where any accident at a workplace occurs which leads to the death of any employee, the employer of that employee shall, as soon as is reasonably practicable, notify the Commissioner of the accident. 2) Where any accident at the workplace occurs which leads to the death of any person who is not at work or of any self employed person, the occupier of the workplace shall, as soon as is reasonably practicable, notify the Commissioner of the accident.
3) The employer or occupier, as the case may be, shall thereafter but not later than 10 days after the accident, submit a report to the Commissioner. Duty to notify and report dangerous occurrence. 1) where any dangerous occurrence occurs at a workplace, the occupier of the workplace shall, as soon as is reasonably practicable, notify the Commissioner of the occurrence. 2) The occupier shall thereafter, but not later than 10 days after the occurrence, submit a report to the Commissioner.
Duty to report accident leading to injury. 1) where an employee meets with an accident at a workplace, the employer of that employee shall submit a report to the Commissioner of the accident a) in the case where the employee is granted more than 3 days of sick leave (consecutive or otherwise) by a registered medical practitioner on the account of that accident, not later than 10 days after the 3 rd day of the sick leave. b) in the case where the employee is admitted in a hospital for at least 24 hours for observation or treatment on account of that accident, not later than 10 days after the date of the incident.
2) Where an employee meets with an accident at a workplace which is reported under paragraph (1), and subsequently dies as a result of the injury, the employer of that employee shall, as soon as reasonably practicable, notify the Commissioner of the death. 3) Where any person who is not at work or any self-employed person meets with an accident at a workplace which requires him to be taken to a hospital for treatment in respect of that injury, the occupier of the workplace, shall as soon as is reasonably practicable, notify the Commissioner of the accident.
Duty to report occupational disease 1) Where an employee suffers an occupational disease specified in the Second Schedule to the Act at a workplace, and the employer of that employee receives a written statement prepared by a registered medical practitioner diagnosing the occupational disease, the employer shall, not later than 10 days after receipt of the written diagnosis, submit a report to the Commissioner. 2) Any registered medical practitioner who diagnoses any employee with an occupational disease specified in the Second Schedule to the Act shall, not later than 10 days after diagnosis, submit a report to the Commissioner.
Duty to keep records 1) Every employer and every occupier of a workplace shall keep a record of every notification or report made by him under these Regulations. 2) The employer or occupier, as the case may be, shall keep every record made by him for a period of 3 years from the time of the notification or report. 3) The employer or occupier as the case may be, shall furnish the Commissioner with such extracts of his records as the Commissioner may from time to time require.
Any notification or reporting required under regulations 4 to 7 shall be made in such form and manner as set out at the website http://www.mom.gov.sg/ireport.
7.5 Planning and Management Risk Assessment Procedure The following are the main risk categories to be considered: * Falls of Personnel * Potential of Materials falling on Operatives & Public * Transportation related accidents * Structural integrity of temporary structures * Manual handling of Materials * Fire * Harmful substances * Noise and Vibration * Stress
Falls of Personnel Statistics show that Fall from Height is the number one initiator of both injuries and fatalities in local construction industry. Some areas of high potential risk for this accident: * During erection of scaffolding * Prior to completion of ceiling, cladding and vertical tiling works * During all roofing works * During the installation of external envelope/ glazing * During structural stage with the lack of barricades on open sides
Some safety measures and precautions that can be taken: * Engage only experienced and formally trained personnel for all the above works. * Erect all essential temporary works at both sub and superstructure levels to prevent falls by either physically deterring passageway of personnel or to highlight a dangerous boundary (barricades, net fencing etc). * Ensure that all site personnel working from heights wear their appropriate PPE (safety belts and harness) and they are put in correct usage and hooked to lifeline or other safe structures.
Potential for Materials Falling on Operatives and Public Some areas of high potential risk for this accident: * During transportation of materials * During all superstructure works * During erection of scaffolding * During installation of all overhead facilities and services (suspended ceilings, M&E runs and appliances) * During all roofing works * During installation of external envelope/ glazing
Some safety measures and precautions that can be taken: * Erect all essential temporary works to prevent falls of objects (e.g netting, toe boards) * Ensure all site personnel wear their appropriate PPE (safety helmets). * Provide dumping facilities around the site at all levels (temporary refuse chute ) * Check and ensure regularly the integrity of safety provision (e.g safety nets, hoppers, cables etc)
Transportation-related Accidents Some areas of high potential risk for this accident: * During mobilization of modular office and escalator components * During external, landscaping and ground works * Bilateral traffic between site and public areas * During earthwork and excavation
Some safety measures and precautions that can be taken: * Engage experienced and trained plant operators * Keep site tidy by regular housekeeping and to provide convenient dumping facilities around site * Send operators for training when necessary * Impose speed limit on site * Deploy banksman or traffic warden whenever necessary * Provide adequate signage, barricades, warning sites and lighting (for night works)
Structural Integrity of Temporary Structures Temporary structures are required in all projects but as the word temporary suggest, their integrity is not as sound as permanent structures. Sometimes some compromise are taken like corrosion, physical weathering, deterioration, wear and tear etc. Some areas of potential risk: * During the establishment and erection of temporary structures (like scaffolding) * During all movement and operations on, along or assisted by the structures (like hoisting of heavy components)
Some safety measures and precautions that can be taken: * Engage only professionally qualified engineers to design essential temporary structures and issue certificate of supervision (cos) upon completion. * Recruit only experienced and formally trained tradesmen and personnel to erect the said structures. * Check and regularly maintain all temporary structures (like members, bracing, joints, footings, tie-backs etc)
Manual Handling of Materials Care must be taken when handling site materials as they tend to vary in physical size, weight, texture and integrity. Workers should only handle the quantity comfortable to their own physical strengths and capabilities and in appropriate manner. Certain materials may be hazardous if exposed directly to the human body, and PPE have to be worn while handling them (e.g face masks with air tubing for removal of asbestos from existing structures before demolition etc.)
Fire The PM shall ensure that all strategic locations of fire fighting applicances are made known to the operatives. All site personnel are to be informed of the fire-escape route with appropriate signage and fire drills conducted. Materials that are capable of supporting combustion (timber, diesel etc) have to be properly stored away with local fire-fighting appliances nearby. All fires major or otherwise have to be reported to the PM without delay and a detailed assessment be made.
Harmful substances Certain substances have or emit elements that are harmful to humans (diesel fumes in contained enclosure, hydrogen sulphide in sewers etc). All personnel have to identify the potential dangers that may be present and avoid or handle materials and situations as deemed logical and appropriate.
Noise and Vibration Noise has adverse effect on both the public and operative. Background noises on site have been proven to cause a high level of recorded harm and damages via indirect means. This is especially so when works are carried out in enclosed spaces or basement (like hacking, installation of machinery etc) Illness resulted from the effects of excessive noise can lead to nausea, giddiness, frustration and sometimes violence. Some precautions include the wearing of ear plugs.
Some plants cause high levels of vibration during the operation and some require direct handling (like pneumatic hammers, drills, concrete vibrators etc). Operatives who get in direct contact with sources of vibration daily will have to inform his supervisor so that alternative operatives may be arranged to handle the work, in order not to expose anyone to prolong physical damage.