Workplace Hazards: A Threat to Workers' Senses
There is usually one combination of engineering, administrative, and PPE that is the "best" way to safeguard employees.
- By Mark H. Stromme
- Mar 01, 2004
WORKERS depend on their five senses--sight, hearing, smell, taste, and touch--to keep them alert to their surroundings and to any danger present. It's important to note that four of the five sense organs are housed in the head. The brain (the organizer of all that data collected by the senses) is also located there.
There are effective ways to keep this vital body part safe from workplace hazards. Many employers assume, incorrectly, that personal protective equipment (PPE) is the only way to reduce hazards. However, an employer should first use engineering and administrative controls before, or in addition to, protecting employees with PPE.
Let's take a closer look at these three hazard control methods: engineering controls, administrative controls, and PPE.
Engineering controls are the first step in effective hazard control. They eliminate or reduce exposure to a hazardous chemical or a physical hazard through the use of (or substitution of) some type of engineered machinery or equipment. Simply put: Engineering controls remove, reduce, or eliminate the hazard at the source.
Engineering controls include:
- Hazard elimination/minimization by designing the facility, equipment, or process to remove the hazards, or substituting processes, equipment, materials, or other factors to lessen the hazard;
- Isolating the hazard using enclosed cabs, enclosures for noisy equipment, or other means;
- Isolating the hazard with interlocks, machine guards, blast shields, welding curtains, or other means; and
- Removing or redirecting the hazard, such as with local and exhaust ventilation.
Consider the situation of an employee working on a grinding wheel. This employee will be wearing goggles and a faceshield to protect his or her face and eyes. However, nearby workers without face protection will be exposed to the flying particle hazards.
By installing the grinding wheel in an enclosed booth or room (an engineering control), employees not involved with performing the actual grinding will be protected. The goggles and faceshield protect the employee performing the grinding.
This is an example of using multiple types of hazard control methods (engineering control and PPE) to protect a worker.
Administrative controls are the second tier in the hierarchy of hazard control. When engineering controls don't eliminate the hazard, try using administrative controls.
Administrative controls include:
- Written operating procedures, work permits, and safe work practices;
- Exposure time limitations (used most commonly to control temperature extremes and ergonomic hazards);
- Monitoring the use of highly hazardous materials;
- Alarms, signs, and warnings;
- Job rotation;
- Buddy systems; and
These administrative controls always can be used to control employee exposure. However, human error can affect the application of administrative controls. Therefore, administrative controls shouldn't be relied upon to reduce exposure every single time.
Take the scenario of the person working on a grinding wheel. This employee can wear goggles and a faceshield to protect his or her face and eyes, but nearby workers without this PPE will be exposed to flying particle hazards. If you require that all workers in that area wear eye and face protection, everyone will be protected. But if someone forgets to wear his PPE (human error) and a piece of metal strikes him in the face, he will be injured.
If the engineering control, mentioned earlier, of putting the grinder in an enclosed booth were implemented, this flying particle hazard would be eliminated.
Take the situation of a maintenance employee working on a machine. Because of the head impact hazards present, a policy (an administrative control) was instituted that all maintenance employees must wear hard hats while working on machinery. The policy is designed to protect the worker, but if he or she doesn't wear the hard hat, the administrative control will not work.
What happens if the employee removes his hard hat when working under the machine and strikes his head? Are there engineering controls that could have been implemented to counter the human error of failing to wear the hard hat? Consider wrapping cushioned foam around any exposed hard surfaces with which the maintenance worker's head could come into contact. By implementing this engineering control, the head impact injury hazard would be eliminated.
Remember, engineering controls should always be considered first, before administrative controls are implemented.
Personal Protective Equipment
Personal protective equipment, such as respirators, hearing protection, protective clothing, safety glasses, and hard hats, is acceptable as a control method in the following circumstances:
- When engineering controls are not feasible or do not totally eliminate the hazard;
- While engineering controls are being developed;
- When safe work practices do not provide sufficient additional protection; and
- During emergencies, when engineering controls may not be feasible.
- Use of one hazard control method over another higher in the control precedence scale may be appropriate for providing interim protection until the hazard is abated permanently. In reality, if the hazard cannot be eliminated entirely, the adopted control measures will likely be a combination of engineering and administrative controls, and PPE, used simultaneously.
Perform a Hazard Assessment
To determine whether engineering controls, administrative controls, and PPE are needed, the employer must first assess the workplace to see whether hazards are present or are likely to be present.
Let's go back to our example of the employee working at the grinding wheel in the grinding booth. Not only is the employee exposed to flying particles, there is also the issue of the potential for excessive noise exposure. The hazard assessment needs to measure the noise level in the booth. Because the booth is enclosed, noise levels usually will be amplified. OSHA's occupational noise standard at 29 CFR Part 1910.95 requires companies to provide protection against the effects of noise exposure when the noise levels exceed an 8-hour time-weighted (TWA) average of 90 decibels (dB).
To begin a noise evaluation, consider these four points:
- Noise level in the work area;
- Equipment and processes that are generating the noise;
- Which employees/job functions are exposed to the noise; and
- Length of exposure to the noise (check production records).
Hazards of PPE
When it is determined that engineering and administrative controls are not sufficient to protect workers, the use of PPE becomes necessary. When this is the case, PPE should be used in conjunction with other protective methods.
The use of PPE can itself create significant worker hazards, such as heat stress, physical and psychological stress, and impaired vision, mobility, and communication. In general, the greater the levels of PPE protection, the greater the associated risks. For any given situation, equipment and clothing should be selected that provide an adequate level of protection. Over-protection as well as under-protection can be hazardous and should be avoided.
Using PPE improperly, or in a manner unsuited to its design and purpose, is often worse than using no protection at all. Without any protection, the worker knows he or she is vulnerable and perhaps, takes precautions. With some protection, the worker may rashly blunder into severe difficulty, thinking he or she is safe.
Develop a PPE Program
If there are situations in which PPE might be used, a written PPE program should be established. (For example, OSHA requires a written program for selection and use of respirators at §1910.134.)
The two basic objectives of any PPE program should be to protect the wearer from safety and health hazards and to prevent injury to the wearer from incorrect use and/or malfunction of the PPE. To accomplish these goals, a comprehensive PPE program should include:
- Hazard identification;
- Medical monitoring;
- Environmental surveillance;
- Selection, use, and decontamination of PPE; and
The written PPE program should include policy statements, procedures, and guidelines. Make copies available to all employees and have a reference copy available at each work location. Also, make available technical data on equipment, maintenance manuals, relevant regulations, and other essential information.
Controlling Noise Exposure
What about controlling noise exposure? Engineering or administrative measures such as the following are always the first step in reducing worker exposure to noise:
- Set up noisy machinery in a separate area, away from as many workers as possible.
- Place machinery on rubber mountings to reduce vibration.
- Use sound-absorbing acoustical tiles and blankets on floors, walls, and ceilings.
- Arrange work schedules to cut down on the time each worker spends in a noisy area.
Many machines currently meet noise specifications because manufacturers have responded to the need to cut noise. Some equipment, however, such as saws and punch presses, can't be made to run any quieter, so proper hearing protection is a must.
Remember that administrative controls, engineering controls, and PPE are not mutually exclusive. Employers may need to use multiple types of controls to prevent employees from being overexposed to noise.
Training is one of the most important elements in any safety compliance program. OSHA feels that it is very important to provide workers with complete information as to the:
- Processes they are involved in;
- Equipment they might need to use;
- Protection available; and
- Potential effects of exposure to hazards.
In the examples mentioned in this article, train all affected employees in:
- How the administrative and engineering controls protect them; and
- How to properly put on and take off PPE, if its use is necessary.
There are different ways to protect workers effectively from hazards. However, there is usually one combination of engineering, administrative, and PPE that is the "best" way to safeguard employees.
This article originally appeared in the March 2004 issue of Occupational Health & Safety.