Safety Engineering
MOS 5201, Safety Engineering 1
Course Learning Outcomes for Unit VII Upon completion of this unit, students should be able to:
3. Apply appropriate calculations to the hazard analysis process. 3.1 Classify workplace hazards using a risk assessment matrix.
4. Compare control strategies based on effectiveness.
4.1 Recommend controls to reduce risks associated with workplace hazards.
6. Examine risk assessment methods related to occupational safety and health. 6.1 Discuss how prevention through design (PtD) can be used to reduce the risks associated with
operations.
7. Recommend controls for workplace hazards through application of risk assessment results. 7.1 Select the most effective control methods to implement using risk assessment techniques.
Course/Unit Learning Outcomes
Learning Activity
3.1 Unit Lesson Unit VII Project
4.1 Unit Lesson Chapter 33 Unit VII Project
6.1 Unit Lesson Chapter 33 Unit VII Project
7.1 Unit Lesson Chapter 33 Unit VII Project
Reading Assignment Chapter 33: Ergonomics
Unit Lesson Ergonomics is a specialized safety field that evaluates how individuals relate to their work environment. The Occupational Safety and Health Administration (OSHA, n.d.-a) states ergonomics fit a job to a person. This definition helps illustrate the problems typically associated with ergonomics issues. With such a variety of workers in the workforce, it is difficult, if not impossible, to design controls that work exactly right for every worker. One of the most common hazards that ergonomics must address is repetitive motion injuries. Repetitive motion injuries occur when workers have to repeat the same motion continually to complete a task, and the motion is not performed in what is called a neutral position. When tasks require repetitive motions using awkward positions, the muscles, nerves, tendons, and ligaments in the body can be stressed, leading to injuries.
UNIT VII STUDY GUIDE
Ergonomics Assessment and Control
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The most common term used for injuries associated with repetitive motions is musculoskeletal disorders (MSDs) (OSHA, n.d.-a). Carpal tunnel syndrome and tendonitis are very common forms of MSDs that are present in both industrial and office settings. These two MSDs are most commonly associated with repetitive motions like using a screwdriver to repetitively connect parts on an assembly line or typing in an office. Another type of MSD involves soft-tissue injuries like muscle strains. These types of injuries are more commonly associated with lifting heavy loads using improper techniques. This type of heavy lifting may also result in other injuries such as torn rotator cuffs and ligament damage. When MSDs are present in a workplace, designing and implementing controls can be more difficult. In many cases, designing and implementing controls will require the use of specialists, including safety engineers. Sometimes, controls must be designed at the manufacturing level because specialized tools are required. An example would be specialized, powered screwdrivers that are designed so the human hand is in a neutral position during use. A difficulty that is usually present in designing and implementing ergonomically specialized controls is simply related to differences in workers. The textbook includes a discussion of anthropometry in Section 33-2 on page 464 (Brauer, 2016). As stated in the textbook, anthropometry is the study of measurements of the human body. Because workers can vary greatly in measurements, such as standing height, sitting height, and arm length, designing controls can be very difficult. Some workers with their arms in a neutral position may accomplish a task designed to be performed at a specified height, but other workers would have their arms placed in an awkward position, leading to MSDs. It is typically impossible to design a specific control that works adequately for 100% of workers. For this reason, it is common for controls to be designed to work for a percentage of the worker population based on anthropometric readings. It is very common for controls to be designed to work for the 5th to the 95th percentile anthropometric readings. The safety professional must realize, however, that the 5th to the 95th percentile readings may be for males, which would not necessarily be the same as the 5th to the 95th percentile readings for females. Regulating ergonomic issues can be just as difficult for OSHA as it is for employers. OSHA issued a proposed comprehensive ergonomics standard on November 23, 1999. The final standard (29 CFR 1910.900) was issued on November 14, 2000, with an effective date of January 16, 2001. The federal elections held in 2000 resulted in a change in control in both Congress and the Oval Office. Congress used the Congressional Review Act of 1996 to rescind the ergonomics standard, and President George W. Bush signed the joint resolution of Congress on March 20, 2001, which repealed the standard. Essentially, this ended OSHA’s ability to publish or enforce a comprehensive ergonomics standard in the future. OSHA currently regulates ergonomics issues using the general duty clause of the OSH Act. The general duty clause requires employers to keep their workplaces free from recognized serious hazards, including ergonomic hazards. In order to issue a citation for an ergonomic issue using the general duty clause, OSHA must show that an ergonomic hazard exists, the hazard is recognized in the industry, the hazard is causing or is likely to cause serious physical harm to employees, and that a feasible means exists to reduce the hazard (OSHA, n.d.-b). The approach OSHA has taken to assist employers in reducing risks associated with ergonomic hazards is to issue guidelines for industries with high rates of MSDs. OSHA has made it clear that, as guidelines, they do not have to be implemented by employers and will not be used as a basis for a citation (OSHA, 2004). They do provide information about controls to help reduce the incidence of MSDs in that industry. Thus, the guidelines can be used to understand the controls that OSHA considers effective in reducing risks for ergonomic hazards in certain industries. Currently, OSHA has developed guidelines for the poultry processing industry, meatpacking plants, foundries, nursing homes, shipyards, and retail grocery stores. Additionally, the National Institute for Occupational Safety and Health (NIOSH) has published a guide that discusses the elements of an effective ergonomics program (see the Suggested Readings list in this unit). To illustrate how OSHA approaches ergonomic controls, we will look at one of the guidelines in the following paragraphs.
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An example of an OSHA guideline for a specific industry is the guideline for shipyards (OSHA, 2008). One reason OSHA chose this particular industry for a guideline is “that many shipyard tasks are performed in awkward body postures, at nonadjustable workstations, on scaffolds, and in enclosed or confined spaces” (OSHA, 2008, para. 1). OSHA identified many typical ergonomic hazards in shipyard work that we have already mentioned, including repetitive motions, work requiring excess force, work using awkward positions, and heavy lifting. Additionally OSHA identified the use of vibrating tools and temperature extremes as additional ergonomic hazards. OSHA recommended a multipronged approach to address the risks associated with the hazards at shipyards. First, they recommend that ergonomic programs be site-specific because each location will likely have different hazards. OSHA has emphasized several variables, not only in the guidelines for shipyards but also for other industries as well. The first variable is to gain management support for ergonomic programs. OSHA considers management support to be critical to the success of an ergonomics program (OSHA, 2008). Management support is not only necessary to obtain the necessary funding for the program but also to obtain the necessary buy-in from workers. Workers will typically support programs to a greater degree when they perceive that management truly supports the program. A lack of support from management can result in an ineffectual ergonomics program. A second variable that OSHA considers as extremely important is employee involvement in the design and implementation of the program (OSHA, 2008). Employees can provide valuable input in several areas. First, they typically provide the most accurate information about the causes of MSDs. Since they are the ones performing the tasks producing the MSDs, they will know what specific tasks and positions are related to the risks of MSDs. Second, they will often have important suggestions about the most effective ways to reduce the stresses that lead to MSDs. Finally, involving workers in the process typically results in a greater compliance with the use of controls after they have been implemented and in providing feedback as to the success of the controls in reducing MSDs. Another important variable in an ergonomics program is training (OSHA, 2008). It is extremely difficult for ergonomic controls to be effective unless workers are trained in the reason for the controls and the proper procedures in using the controls. If training is not performed or not performed well, workers may develop their own methods for using the new controls. If their procedures are not the procedures that were intended by the manufacturer, the new techniques could actually increase the risks of MSDs. One important task that is required for any effective ergonomics program is to identify the ergonomic hazards and assess the risks associated with the hazards. The hazard assessment and risk assessment techniques we have already discussed in this class can also be applied to ergonomic hazards. As with other hazards, it is important to periodically conduct ongoing hazard assessments and risk assessments for ergonomic issues to evaluate the effectiveness of controls and to update the controls. In the Guidelines for Shipyards, OSHA summarizes some controls that it would recommend for some specific ergonomic hazards (OSHA, 2008). The first is to install task lighting. The effectiveness of this control method may not be obvious as it relates to ergonomic hazards, but OSHA mentions that proper lighting can reduce the need to bend at awkward positions to see the task, reducing stress on some muscles and tendons. Another potential control that OSHA recommends is the placement of tools at a height that does not require the worker to either bend or reach excessively to retrieve the tools. This can be accomplished by using boards or racks with the tools placed at a height between the knees and shoulders. OSHA also recommends the use of portable benches and platforms that allow a worker to perform tasks at heights without having to reach excessively. Portable carts, hand trucks, and pallet jacks can be used to reduce the requirement to move heavy objects using awkward positions.
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These are a few of the many recommended controls OSHA included in its guidelines for shipyards. A review of these controls and the other controls contained in the guidelines shows the common sense approaches that OSHA recommends. Many of the recommended controls are fairly inexpensive and easy to implement. When compared to the increasing costs associated with MSDs, the costs associated with implementing ergonomic controls can, in many cases, be easily justified. While a specially trained safety engineer may be required to design and implement controls for ergonomic hazards in many instances, a review of the guidelines that OSHA has already published shows that many of the recommended controls can be implemented without the requirement for a safety engineer.
References Brauer, R. L. (2016). Safety and health for engineers (3rd ed.). Wiley. JonKline. (2013). Welder welding [Image]. Pixabay. https://pixabay.com/en/welder-welding-industry-industrial-
673559/ Occupational Safety and Health Administration. (n.d.-a). Ergonomics: Overview.
https://www.osha.gov/SLTC/ergonomics/ Occupational Safety and Health Administration. (n.d.-b). Ergonomics: Standards and enforcement FAQs.
https://www.osha.gov/SLTC/ergonomics/faqs.html Occupational Safety and Health Administration. (2004). Reminder: Guidelines not basis for citation
[Memorandum]. https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=24 894
Raised workstation for welding (JonKline, 2013)
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Occupational Safety and Health Administration. (2008). Guidelines for shipyards: Ergonomics for the prevention of musculoskeletal disorders (OSHA Publication No. 3341-03N). https://www.osha.gov/dsg/guidance/shipyard-guidelines.html
Suggested Reading In order to access the following resources, click the links below. There are several programs that employers use to reduce the number of musculoskeletal disorders (MSDs). One popular program is to have workers stretch prior to starting their work shift. The following article evaluates the effectiveness of these types of programs. Choi, S. D., Rajendran, S., & Ahn, K. (2017). Stretch & flex programs: Effects on the reduction of
musculoskeletal disorders & injuries. Professional Safety, 62(5), 38–43. https://libraryresources.columbiasouthern.edu/login?auth=CAS&url=http://search.ebscohost.com/logi n.aspx?direct=true&db=a9h&AN=123022238&site=ehost-live&scope=site
The National Institute for Occupational Safety and Health (NIOSH) has published a manual that summarizes the elements that are present in an effective ergonomics program. Cohen, A. L., Gjessing, C. C., Fine, L. J., Bernard, B. P., & McGlothlin, J. D. (1997). Elements of ergonomics
programs: A primer based on workplace evaluations of musculoskeletal disorders (NIOSH Publication No. 97-117). https://www.cdc.gov/niosh/docs/97-117/pdfs/97-117.pdf
Many processes are used to manage ergonomics programs. The ISO 45001 standard was recently released as a draft. The standard provides another method to manage ergonomic programs. The following article discusses the draft standard and how it can be used to manage ergonomic risks. Rostykus, W. G., Ip, W., & Dustin, J. A. (2016). Managing ergonomics: Applying ISO 45001 as a model.
Professional Safety, 61(12), 34–42. https://libraryresources.columbiasouthern.edu/login?auth=CAS&url=http://search.ebscohost.com/logi n.aspx?direct=true&db=a9h&AN=119843039&site=ehost-live&scope=site
Learning Activities (Nongraded) Nongraded Learning Activities are provided to aid students in their course of study. You do not have to submit them. If you have questions, contact your instructor for further guidance and information. The Occupational Safety and Health Administration (OSHA) has developed a training video that shows how an ergonomics program should be implemented. Click on the following link, and view the video titled “Ergonomic Programs That Work:” https://www.osha.gov/video/ergonomics/index.html. Click here to access the transcript for the video.