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Occupational Hazards of the Safety Engineer: OSHA Meets UL

1403 occupational-hazards coverThe job of the product safety engineer is to reduce the risks associated with a product to an acceptably low level. The product safety engineer is interested in protecting the life and health of the customer who will use the product. However, the testing involved in safety engineering can entail some risks of its own. The environment for safety testing itself needs to be designed to provide an adequate level of safety for the person performing the test. This requires appropriate test equipment, properly designed environment, well documented procedures, personal protective equipment, training and monitoring of personnel who have access to the test lab.

There are numerous potential risks in the safety test lab, and these typically are similar to the potential risks we test for in our products. There are electrical hazards including shock and arc blast. There are thermal hazards including burns and the risk of flame. Mechanical hazards include risks from hazardous moving parts or from heavy objects crushing body parts. High energy lasers can be exposed in testing, and electrical arcs will generate significant amounts of UV light creating a risk of cataract formation in the eye. Medical products may generate ionizing radiation. There are even chemical exposure hazards for some testing. All of these potential risks need to be properly addressed and mitigated.


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VSWR and its Effects on Power Amplifiers

Voltage Standing Wave Ratio results from an impedance mismatch between a source (an amplifier) and a load (test application). This mismatch can influence the performance of the source.

It is difficult to find statistics for injuries in the product safety testing profession. As a profession, the number of practitioners is small and it doesn’t warrant its own category by the U.S. Bureau of Labor Statistics (BLS). However, the BLS does record injuries as a rate per 100 workers, and it is reasonable to put product safety engineering in the same category as electrical manufacturing. For the most part, the types of hazards are similar. While the time spent at a desk will lessen the product safety engineer’s total exposure time to hazards, it also reduces their experience and practice. An analogous situation would be comparing a professional carpenter versus a weekend woodworker. The professional may be exposed to the risk of injury for 40 hours a week, but this gives them the practice and experience to do the work right. The weekend woodworker may spend only 4 hours a week with a table saw, but their lack of experience significantly raises the risk of injury.

The BLS keeps records of reportable injuries, which are injuries severe enough to require medical treatment. The most recent BLS statistics are for 2009 where there were 3.5 reportable injuries per 100 workers in the electrical equipment, appliance and component manufacturing industry [1]. This is the most appropriate recorded category to extrapolate for product safety engineering and it shows a real risk of injury. Product safety testing is too small of an industry to be broken out separately by BLS, and it is likely that many injuries sustained during safety testing are not reported as worker compensation claims.

The rate of fatalities is a harder to extrapolate as the total number is lower and doesn’t allow the BLS to categorize fatalities by narrow industry sectors. The total for 2009 in the United States was 4,551 out of approximately 130 million workers [2]. The fatality rate for the manufacturing sector was only about two thirds the overall rate for private industry, and this represents about one fatality per 1500 injuries in the electrical manufacturing sector. I do not have sufficiently specific data and I will not extrapolate to the product safety testing industry.


Product safety testing laboratories must comply with the applicable occupational health and safety regulations of the jurisdiction in which they are located. The general principles of regulations are generally similar between North America and Europe. The application of these principles and the level of enforcement may be more variable in other jurisdictions, but I will address The United States and Canada specifically and Europe in general.

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The governing authority in the United States is the Occupational Safety and Health Administration (OSHA) under the Department of Labor [3]. The OSHA rules apply to almost all employees in the private sector. Although there is a common belief that small employers are exempt from OSHA rules, this is a misunderstanding. The enforcement procedures may differ depending on the employer’s size, and although OSHA will rarely audit a company with ten or fewer workers, these companies are still subject to the regulations. The OSHA regulations cover general work practices and some specific work situations. However, the requirements are NFPA and ANSI standards which are incorporated into OSHA regulations by reference [4]. The OSHA directly covers requirements for training, monitoring and reporting of injuries along with safety practices common among different work environments.

While OSHA is reviewing and adoption NFPA 70E for electrical safety, it is currently a reference document not carrying mandatory requirements. Following NFPA 70E will demonstrate due diligence should an OSHA inspector arrive at a facility. NFPA 70E is not to be confused with NFPA 70. Whereas NFPA 70 covers the rules for the installation of electrical equipment, NFPA 70E covers the rules for safe work practices around exposed hazardous voltages. Additional applicable standards referenced by OSHA are numerous and include, but are not limited to, ANSI standards such as ANSI Z87.1-89 for eye protection, ANSI Z87.2 for respiratory protection and ANSI A14.2-56 for metal ladder use. Additional regulations will apply for specific risks such as laser and X-ray testing.

The regulations for Canada are similar in their technical requirements. The regulations are governed by Health Canada under the Canada Occupational Health and Safety Regulations [5][6]. Many specific requirements are covered by referenced standards including the Food and Drugs Act, Hazardous Products Act, Nuclear Safety and Control Act, Radiation Emitting Devices Act and Controlled Products Regulations [7-11]. The Controlled Products Regulation for example specifically covers the marking and warning requirements for chemicals and hazardous materials. The specific requirements are very similar tFo those called out by OSHA in the United States.

European requirements will vary from country to country. The European Union does set some standards since the EU is intended to allow the movement of workers across borders without problems. The body setting policy at the European Union level is the European Agency for Safety at Work [12]. As with product safety regulations, there are EU Directives regarding occupational safety that member bodies are required to incorporate into national law. The framework is established in Directive 89/391 with additional Directives written to cover physical hazards, noise, radiation exposure, personal protective equipment, hazardous material handling and marking and many more potential hazards [13][14]. These Directives in turn may have specific applicable standards. For example, EN 50191 covers the installation and use of electrical test equipment and EN 60825-4 covers guarding and protection when there is exposure to Class 3 or Class 4 lasers. Each country must adopt these regulations as a minimum standard, but individual countries may choose to enact stricter regulations. The policy regarding the enforcement of regulations is handled at the national level and is not determined by the European Commission.


Many product safety engineers will groan when they think about OSHA looking at their lab, but the general approach espoused by Environmental Health and Safety (EH&S) professionals can be implemented with minimal hassle and significant benefits. A six step approach can be used; eliminate the risk, provide adequate guarding and protection, use proper personal protective equipment (PPE), provide proper hazard marking and warning, train the affected employees and use continuous improvement. Although the final item isn’t always included in some safety programs, it is important. Proper analysis is required whenever there is an injury or even a “near miss”. Continuous improvement allows you to better focus a general safety program to the narrow field of hazards and issues found in safety certification testing. These issues are determined by systematic causal analysis of incidents that have occurred.


Product safety testing involves abusing products to make sure that they fail in a safe manner. This may mean that the product safety engineer will be exposed to hazards, but the exposure can be controlled through the use of safe work practices. For example, measurements of hazardous voltages can be made without exposing personnel to those voltages by applying test probes using clip-on leads while the equipment under test (EUT) is disconnected from power. The test engineer should use enough test leads and meters to simultaneously record necessary voltages at once. Power can then be applied after all test leads are secured. This eliminates the risk of electrical shock by placing the hands close to hazardous voltages, and it reduces the risk of an arc flash from a test probe accidentally shorting out terminals as it is inserted into live equipment. Another example of risk reduction is the addition of outriggers during the stability testing of large, heavy equipment. The outriggers will stop the fall of equipment if it should start to tip over when subjected to the test force. Alternately, a large test jig can be used that will arrest the fall of equipment when it reaches a tilt of 12¡, allowing a 10¡ tip test without the risk of equipment falling over onto personnel. Consider requiring more than one person be present in the laboratory when any potentially hazardous testing is performed. The second person should be clear of the area where the test is being performed so that they will not be put at risk should something go wrong with the test.


The test laboratory should be designed with the assumption that problems may occur and will need to be addressed. Safety test laboratories should have two means of egress where possible, with the two doorways placed at opposite ends of the room. Security and other design concerns will typically result in doors that swing into the laboratory. If possible have one door that opens out and that has panic hardware that allows the door to be opened without the use of hands, such as a push-bar across the door. Each test area should have an egress route at least 1.25 meters wide. Practice good housekeeping to keep these aisles clear of test equipment and storage boxes. The laboratory should have adequate lighting, exit signage and emergency lighting. Make sure the lab has adequate cooling to handle the heat load that will be generated by the EUT. I once tested a 12 kW load in a room with 4 kW of cooling, and the room temperature finally stabilized at 46° C. This would have been an unacceptable environment had somebody been required to work in the room constantly during the testing. Eyewash stations and showers may be required depending on the chemicals that are used in the laboratory.


The next step is to provide adequate guarding and protection. Flammability testing should be done in a fume hood that will safely extract the combustion gasses from the room. The same fume hood can be used for other tests where volatile chemicals may be used or testing where there may be toxic gasses released into the air. The room itself should have a sprinkler system to protect in the event that a fire does start and get out of control. Hand-held fire suppression equipment should be available should materials ignite during fault testing. Sand or fire blankets can be used for small fires allowing for an easier cleanup. Special fire suppression equipment may be needed depending on the materials being tested, particularly with alkali metals such as lithium.

Some fault testing can result in flying debris, such as testing fuses at high fault currents. Current limiting devices can fail catastrophically when exposed to currents beyond their interrupt ratings. Plexiglas guards can be used to provide a barrier between equipment and personnel during fault testing if there is a risk of debris flying.

Flammable chemicals should be stored in an approved flammable storage cabinet. Chemicals should be stored in their original containers. If smaller volumes of chemicals are moved to another container, that container must be properly marked with the appropriate chemical properties.

If the EUT generates radiation, shields against that radiation need to be provided for the test engineer. This applies for both ionizing radiation and nonionizing radiation such as a laser. Wearable monitors may be required depending on the type of radiation.

Additional equipment may depend on the type of testing being performed. If your laboratory staff must work with tall equipment, consider providing personnel with a rolling platform ladder (Figure 1). This will provide a large and stable work surface for working above ground level and is preferable to a step ladder. Provide lifting equipment and hoists if personnel must handle heavy equipment or components. The personnel who use this equipment must be trained in its use. (See section entitled “Training”.)

Figure 1: Rolling platform ladder


The safety laboratory needs to be designed with the proper electrical connections for the type of equipment to be tested. This may mean providing a variety of outlets of different ratings. One technique is to provide a higher current multi-phase outlet, and then to use adapter boxes that provide specific outlets, each with the proper overcurrent protection. Consider installing an Emergency Power Off (EPO) button that shuts off selected power in the room. The EUT gets connected to a protected outlet, and if there is a problem of such severity that the test engineer cannot easily disconnect power, the EPO can be used to shut off power to the EUT. The EPO can also be used to disable the door lock via an electronic strike plate, allowing entry by emergency responders should there be a situation in the lab requiring fire or medical personnel. In such cases, an indicator light should be placed outside the door to the laboratory to indicate that the EPO has been activated. Please note that the EPO should not turn off lights in the laboratory.

Ground Fault Circuit Interrupters (GFCIs) are required for outlets in close proximity to sources of water. However, GFCI should not be used in other locations for supplementary protection. GFCIs are susceptible to nuisance tripping due to the leakage current of ITE, and they can be impractical in the laboratory environment. Safe work practices are required to reduce the risk of exposing personnel to fault current. AFCIs are susceptible to tripping during abnormal condition testing and could terminate testing prematurely. Arc Fault Circuit Interrupters (AFCIs) also should not be used in a safety laboratory to provide supplementary protection. AFCI’s intended purpose is to shut off power when arcing can go undetected in a residential environment where there are lots of flammable materials. AFCIs are not used in commercial environments in general and would provide few benefits in the safety laboratory.

If you perform fault testing that will result in tripping a branch circuit breaker, you need to take additional precautions. Circuit breakers are not designed for repeated tripping. Their detents and internal components will weaken slightly with each trip. Ground faults are especially hard on circuit breakers and significantly shorten their operating lives. Instead of depending on the branch circuit breaker to terminate a test, insert overcurrent protection between the EUT and the branch circuit breaker. This supplementary overcurrent protection must be of a type and rating such that it will open before the branch breaker, and it should be installed in such a way that it can be easily and safely replaced. The supplementary protector can be replaced as it degrades preventing the need to replace circuit breakers in an electrical panel. This protection can be installed in the previously mentioned adapter boxes. The box can then be unplugged and safely disassembled to replace the supplementary protector.


All personnel who use the lab need to be issued the proper personal protective equipment (PPE) for the type of work that they do. The type of PPE should be based on the testing performed and the risks to which the personnel will be exposed. It is also important to note that “personal” is part of PPE. Each employee who works in the laboratory should be issued their own PPE. It is not to be shared among employees. PPE needs to be chosen in the correct size and type for the employee and they need to be trained in its proper use. Employees need to understand that if they don’t have the proper PPE, they should forego the test until it can be done safely.

Safety glasses should be worn in almost any safety test laboratory as they will be recommended for many types of tests. Physical tests, ranging from drop tests to impact tests, may result in flying debris. Abnormal condition tests can have unpredictable results that can also result in flying debris. In the United States, NFPA 70E requires safety glasses be worn whenever working around exposed hazardous voltages. Electrical arcs generate intense ultraviolet light which can contribute to cataract growth in the eyes, so the glasses should provide UV protection in additional to impact protection.

PPE will be needed as physical protection for a number of risks possible in the test laboratory. Hearing protection may be required if testing will involve loud equipment. Safety shoes should be worn when working with heavy equipment to protect feet from crush injuries. These shoes should also have electrically insulating soles to reduce the shock hazard. Protective gloves may be required for some types of tests (Figure 2). Different gloves may be needed for protection against thermal burns, sharp edges or chemical hazards. Chemical exposure may also dictate the use of respirators. If so, the respirators need to be fitted properly, the filters need to be selected based on the hazard and the employee needs to be medically evaluated and well trained in the use of the respirator.

Figure 2: Electrical gloves

NFPA 70E imposes fairly strict requirements for PPE for working with exposed hazardous voltages, so it is best to eliminate the need for the test engineer to place their hands in the equipment while it is live. If this must be done, NFPA 70E will require differing levels of protection depending on the voltages present. This protection includes electrical gloves with leather protectors, safety glasses, face shields and flame resistant clothing. The PPE required for testing a 120 V hand mixer may be simple, but much more would be required for testing a 250 kW, 480 V uninterruptible power supply. Do not rely on the practice of keeping one hand in your pocket. This may reduce the risk of hazardous current running through your heart, but you still run the risk of creating an accidental short circuit. This could still allow hazardous current to run through your hand resulting in significant burns. In higher power equipment, it can result in an arc flash or arc blast that can do even more damage.

Make it easy for employees to keep their PPE in or adjacent to the laboratory. Even if the employee’s office isn’t far away, there can be the temptation to just run a quick test even if they forgot to bring their PPE. Lockers or cubbies allow easy storage of safety glasses, lab coats, safety shoes, ear protection and other PPE. Provide additional PPE if you have regular visitors to the laboratory. Safety glasses and ear plug dispensers can easily be placed immediately outside the laboratory area allowing the quick outfitting of visitors when needed.


Marking and warning should be used where hazards cannot be eliminated, guarded or controlled below safe levels. Chemicals should be properly marked where they must be used and the Material Safety Data Sheets (MSDS) must be available to personnel to provide them with the proper warnings, PPE requirements and information (Figure 3). Mark areas where there will be exposed hazardous voltages. The test engineer may be aware of the exposed voltages, but there may also be a possibility of others entering the lab without such knowledge. These people need to be able to see the proper warning signs to know the hazard is present. Similar marking should be used for hot surfaces or exposed hazardous moving parts. The National Electrical Code prohibits placing any object in front of an electrical panel, so mark the proper exclusion area around the panel. Use floor marking for areas used for storage of large items to clearly delineate storage areas from aisles.

Figure 3: MSDS station

Certain hazards will require additional marking. There will need to be marking on the door into the laboratory if there are radiation hazards, whether they are ionizing or nonionizing. Specific information about lasers in the laboratory will need to be marked including the laser class and the wavelength. Signs on the door should indicate the required PPE if there is ongoing testing dictating specific PPE be used at all times.


All affected employees need the proper training to reduce their risk of injuries. Affected employees include not only those performing the testing, but those with access to the laboratory area while testing is being performed. Personnel unfamiliar with specific testing may enter the lab and these people need the training to be able to assess and handle the risks present. It is important to document which employees have been trained and what hazards they have been trained to handle. An employee not trained to handle a specific hazard should not be permitted to perform testing where that hazard may be present. Training needs to be repeated periodically both as a refresher and to ensure new standards and requirements are well communicated.

The various regulating agencies, such as OSHA, mandate the training. Employees must be trained in the use of PPE before they can perform the tasks that require the PPE. If special equipment is required to perform a task, the affected employees must be trained to use the equipment. Employees must be trained in proper ergonomics, lifting techniques and use of hoists if their job requires them to lift heavy loads.

Training on its own has a limited benefit if there isn’t enforcement of the rules. Enforcement need not be draconian, but it does need to provide an incentive to follow safe work practices. Laboratory safety needs to be part of the corporate culture, and the laboratory manager is responsible for the safety of the employees in the lab. It is important that the managers cultivate a culture of safety so that they can act as guides, not policemen.


Any laboratories safety program should include continuous improvement. Work practices may need to be tailored to the specific testing performed. If there is an incident, update the workplace practices for the laboratory to address appropriate corrective actions for the issue. Look for near misses and use them as an opportunity for improving work practices. Work with your employer’s Environmental Health and Safety group to help minimize risks in the laboratory.

Continuous improvement should not be just a top-down program. All of the laboratory personnel should be involved. Suggestions that come from the workers in the lab are more likely to be easy to implement than programs dictated from management alone. Track incidents to determine if changes are having the intended effect.


The risk of injury in the safety test laboratory may seem low, but there are real hazards that do result in injuries and even a risk of death. The proper design of the laboratory along with good training and the proper use of protective equipment can significantly reduce the risk of injuries. The implementation of proper safety can be done cost effectively if designed into a laboratory program. These costs can pay for themselves by eliminating possible higher expenses ranging from noncompliance fines from the Occupational Safety and Health authority, withdrawal of an occupancy permit for unsafe condition, lost time from injured workers and increased workers compensation costs.


I would like to thank Lauri Johns-Andersch, Microsoft’s Employee Safety and Health Program Manager, for help reviewing this paper and teaching me the details of the legal requirements of OSHA compliance.


  1. Workplace Injuries and Illnesses for 2009, Bureau of Labor Statistics, 2010,
  2. Revisions to the 2009 Census of Fatal Occupational Injuries (CFOI) Counts, Bureau of Labor Statistics, May 2011,
  3. 29 CFR 1910 – Occupational Safety and Health Standards, United States Department of Labor.
  4. 29 CFR 1910.6 – Occupational Safety and Health Standards, Incorporation by Reference, United States Department of Labor.
  5. Health Canada – Environmental and Workplace Health.
  6. Canada Occupational Health and Safety Regulations, Canada Department of Justice, May 2009.
  7. Food and Drugs Act (R.S.C., 1985, c. F-27), Canada Department of Justice, 2008.
  8. Hazardous Products Act (R.S.C., 1985, c. H-3), Canada Department of Justice, December 2010.
  9. Nuclear Safety Control Act (S.C. 1997, c. 9), Canada Department of Justice, 2010.
  10. Radiation Emitting Devices Act (R.S.C., 1985, c. R-1), Canada Department of Justice, October 2010.
  11. Controlled Products Regulations (SOR/88-66), Canada Department of Justice, February 2010.
  12. European Agency for Safety and Health at Work.
  13. Directive 89/391 on the introduction of measures to encourage improvements in the safety and health of workers at work, European Commission, June 1989.
  14. European Directives regarding Occupational Health and Safety.

© 2011 IEEE. Reprinted, with permission, from the proceedings of the 2011 IEEE International Symposium on Product Compliance Engineering.

Ted Eckert
is currently a compliance engineer for Microsoft Corporation where he is responsible for products including video game systems and tablet computers and where he serves as Microsoft’s representative to the U.S. National Committee for TC108. Previously, he was a Staff Compliance Engineer at APC-MGE, a division of Schneider Electric. Over his career as a product safety engineer, Ted has tested industrial electronics, power distribution products, air conditioners, information technology equipment and toys.

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