Construction design can minimise risks

One of the best ways to prevent and control occupational injuries, illnesses and fatalities is to design out or minimise hazards and risks early in the design process. Prevention through design (PtD) is an engineering initiative, which was launched in the US by NIOSH, that attempts to mitigate hazards in the construction sector in the design stage. The concept has been around a while, but there are still some barriers to its adoption globally.

There has been global growth in the recognition of prevention through design (PtD) as a cost-effective means to enhance occupational safety and health. The National Institute for Occupational Safety and Health (NIOSH) in the US has defined PtD as addressing workplace health and safety needs in the design process to minimise the work-related hazards and risks associated with the construction, manufacture, use, maintenance and disposal of facilities, materials and equipment.

The UK began requiring construction companies, project owners and architects to address safety and health during the design phase of projects back in 1994, and companies there have responded with positive changes in management practices to comply with the regulations. Design firms there have provided certain architects with construction and workplace safety training in order for them to meet the requirements of this legislation. While many US companies openly support PtD concepts, no such requirement exists, but applying the principles of designer involvement in the wellbeing of constructors and maintainers can still be accomplished.

The construction industry in Australia has made some significant improvements to its OHS performance in recent years in response to the SafeWork Australia National Strategy 2002-2012 which set ‘eliminating hazards at the design stage’ as one of five national priorities. There has been a 36% decrease nationally over this period in the incidence rate of serious injury within all sectors of the construction industry.

The Australian National Strategy included the adoption of safer approaches across the life cycle of the product of process, the raising of awareness of the importance of safe design among the design professions, clients and community, more systematic and cooperative application of risk management principles by designers, clients and others, and the integration of safe design considerations in procurement.

The ‘Safer Construction’ project, which was commissioned by Engineers Australia and funded by the Cooperative Research Centre for Construction Innovation, established the ‘Guide to Best Practice for Safer Construction’ in 2007, which included management requirements for effective safety risk reduction at all stages in the project process - planning, design, construction and commissioning. The voluntary guide suggests that construction clients should ensure that they engage a designer who has a demonstrated understanding and awareness of safety risk management appropriate to the project requirements.

What are the barriers?

There are good reasons for implementing PtD in construction design. According to American Institute of Architects’ reports, design decisions have a direct impact on the wellbeing of builders, building maintainers and, of course, the building occupants. Some analysis reports have also identified design as a causal factor in a number of fatalities and injuries in the construction industry. So what are the barriers?

During the ASCE Annual Civil Engineering Conference, which was held in Canada in October 2012, John Gambatest, Professor of Civil and Construction Engineering at Oregon State University, gave a presentation on the global growth of the PtD concept. He identified many barriers to implementing PtD, including contractual separation of design and construction, cost and time requirement to implement PtD, unclear authority and responsibility for PtD, lack of knowledge of how to design for safety and competing priorities of safety versus cost schedules.

A report titled Emerging Trends - Constructability through Design Review & Collaboration by Jason Edic and Gary Cunningham said the effort to justify the added expense of safety is sometimes a half-hearted one and the compromises that are based on dollars during construction can translate into compromises of safety for workers. Advocating safety during design of construction projects should be a primary consideration, not a secondary one, to ensure the lives and wellbeing of the people that build, maintain and occupy the facilities are not at risk.

Design features that result in hazardous conditions during construction or for the life of a building can be identified during design review if systems exist that formalise the design review process related to safety. However, safety professionals must have the design review knowledge and designers need occupational safety knowledge in order for this process to work effectively.

The report says a decision to place mechanical equipment on a roof should not be made without a safety professional being part of the process. Design elements such as elevators, stairways and fixed ladders should not be considered without input from a safety professional. A discussion on walking and working surfaces would benefit from the inclusion of a safety professional.

A new approach

Deborah Young-Corbett is an assistant professor of civil and environmental engineering at Virginia Tech and she has been working in the PtD field for some time. She suggests a new approach in her review of the industry’s safety procedures in 2012 which has identified strategies for the construction industry to use to improve its health records.

Young-Corbett provides evidence in her assessment of the industry of a ‘gap’ in the PtD initiative that does not address the approaches to ‘occupational health hazard control’, with the key word being ‘health’. These “health risks arise when workers are exposed to chemical, biological or energetic hazards that might lead to various illnesses or fatalities”, Young-Corbett said.

For example, additional changes in tool selection in masonry could alleviate much of the health risks, according to Young-Corbett. With a masonry operation, a key issue is to reduce the silica dust produced when sawing. Now that wet methods are available for hand-operated grinders used for surface finishing and cutting slots, these devices can keep operators’ exposures to silica below Occupational Safety and Health Administration (OSHA) limits, she noted.

Construction supervisors should also be advocating hand-operated surface grinders that are made with better vacuum dust collection systems, also reducing an operator’s exposure to silica.

In roofing, the workers’ exposure to asphalt fumes and vapours can lead to both acute and chronic effects. Lung cancer is at an elevated risk for asphalt roofers. But, as Young-Corbett argued in her paper, delivery of hot asphalt to a job site via a tanker eliminates the on-site kettle operation for handling and heating the asphalt, and makes a difference to the health of the worker.

Similar relatively simple changes in the practice of welding can also make an impact in the decline of health-related problems. The use of local exhaust ventilation systems can prevent worker exposure to metal fumes during welding, Young-Corbett wrote in her article in the Journal of Civil Engineering and Management.

In general, Young-Corbett said there are still needs for designs for better tools or materials, but in other cases, “effective tools exist but are not widely adopted within the industry … there is a need to elucidate the barriers to PtD adoption and to identify strategies for improved diffusion within the construction industry”.

Several of the research endeavours of Young-Corbett’s laboratory have been in the realm of PtD. A NIOSH-sponsored research project, entitled Dust-control Usage: Strategic Technology Intervention (DUSTI), developed new equipment design solutions for dust control in construction and an intervention for improving adoption rates within the industry. In a project sponsored by the National Science Foundation, a computing system was developed for sensing construction worker exposure to carbon monoxide and wirelessly summoning assistance in the event of overexposure.