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New U.S. standard promotes ‘prevention through design’

By Linda Johnson

The occupational safety concept of prevention through design (PTD) has taken a huge step towards general implementation with the publication in the United States of a comprehensive national standard.

The standard, Prevention Through Design: Guidelines for Addressing Occupational Hazards and Risks in Design and Redesign Processes, is part of a seven-year project begun in 2007 by the American Society for Safety Engineers (ASSE) and the National Institute for Occupational Safety and Health (NIOSH). It provides a detailed guide for organizations on how to implement PTD through their safety and health management system.

Bruce Main, vice-chairperson of the guidelines committee, said the goals of the standard are to “achieve acceptable risk levels; prevent or reduce occupationally related injuries, illnesses and fatalities; and reduce the cost of retrofitting necessary to mitigate hazards and risks.”

The standard, which follows ISO format and has been endorsed by the American National Standards Institute (ANSI), takes effect January 2012. A range of U.S. organizations, from industry and labour to government agencies and professional organizations, participated in the project.

The guidelines cover in detail the implementation of PTD through the four stages of risk management: pre-operational (initial planning and design); operational (identification of risks and remedial action); post-incident (investigation); and post-operational (demolition or reusing operations).

One of the key sections of the standard, dubbed ANSI/ASSE Z590.3-2011, deals with the design safety review, the tool by which the PTD system — including inspection and test protocols — is implemented. A company must do at least one design safety review of their system, said Main, president of Design Safety Engineering.

“Companies find that, the more they do this, the more they are able to influence the design early and end up having more design reviews that focus particularly on safety,” he said.

Another important topic is risk assessment, and the standard describes eight effective techniques. Main says managers must select one, establish parameters and know how to identify hazards. They must also consider different failure modes: “What are the different causes that can lead someone to be in harm’s way?” he says.

The guidelines describe other aspects of a good safety assessment, including assessing the severity of consequences, understanding the hazard control hierarchy, assessing residual risk, documenting results and following up.

Paul Schulte, NIOSH director, education and information division, says the concept of PTD means incorporating occupational safety principles into the design phase of every level of work — from facilities through methods and equipment to the molecules in multi-molecule products — to minimize hazards and risks. In looking at design, PTD principles focus on the worker and how a specific process or machine is used.

NIOSH decided to promote the PTD concept, he added, because it is aimed at eliminating risk. It is thus the most effective of all controls in the “hierarchy of prevention,” a model that ranks various controls on the basis of effectiveness. At the bottom of the pyramid is PPE, while middle levels include administrative and engineering controls and at the top is “elimination through design or redesign.”

“PTD is the most effective level in the hierarchy of controls. It’s also a level at which there can be great financial value, when you look at the whole picture of the impact of bad designs versus good designs,” he said.

Project aspects

Statistics show there are about 5,071 deaths, 3.7 million injuries and 187,000 work-related illnesses in the U.S. annually, Schulte says. These result in $128 to $155 billion in direct and indirect costs.

“There’s also untold pain and suffering on families,” he said. “So it’s critical to think about strategies that will allow us to reduce morbidity, mortality and injury rates, as well as costs related to occupational disease and injury.”

The PTD project had four aspects: research, education, practice and policy, he added.

Research included assessing cases where PTD has been used. The committee learned, for example, that in the U.K. construction industry, where PTD is legally required, 77 per cent of respondents believed PTD had not prolonged the design stage, and 49 per cent said it had not increased their project cost.  At the same time, 67 per cent thought it had promoted worker productivity and 90 per cent that it had increased worker health and safety.

The practice stage included a survey of 35 Fortune 500 companies, which showed that 80 per cent of some of the most progressive businesses in the U.S. know what PTD principles are and 66 per cent were already including them in operations. But only 17 per cent had established performance measures for PTD.

“The old adage of ‘what gets measured gets done’ comes to mind,” Schulte said. “As we think about what steps we want to take further, we’ll want to increase the practice of not only integrating PTD into management systems but also establishing performance measures.”

The policy aspect included establishing a PTD standard and having that standard included in the ANSI-Z10 Occupational Health and Safety Management System. And finally, a major aim of the initiative is to have PTD included in engineering textbooks and curricula, as well as in health and safety courses in various universities.

“The [initiative’s] midrange goal is to try to effect a culture change,” Schulte said, “a change in the thinking of design professionals and of safety and health professionals, so we can incorporate occupational safety and health in the design phase.”

Schulte said he expects PTD will become part of the standard of practice. “I think we’re starting to see evidence that in all facets, from education to practice to policy, PTD is being incorporated,” he said.

“And I’m hoping in the next few years we’ll see an increased rate of incorporation, an increased intensity of practice and a massing of an evidence-base of the effects of doing that in the form of cost reductions and injury and illness reductions.”

PTD is being written into many different industry standards, Main said, because it works well. The concept is also easily integrated into businesses and organizations; it becomes simply a way of doing work.

“It takes a little while to get a company up to speed in doing risk assessments,” he said, “but when you integrate the risk assessment process with the safety design review, it becomes a checkmark that everybody understands and anticipates and makes sure they’re prepared for when you go to the design review. The effort required drops off quite a bit, once you get up the learning curve.”

In addition to ASSE, project partners include the American Industrial Hygiene Association, Liberty Mutual, the National Safety Council and the Occupational Safety and Health Administration. Some 500 representatives from various sectors have also taken part.

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