Remember the Training Component
Keep in mind that the effectiveness of audible alarms tends to diminish over time as employees get accustomed to the noise.
- By Mark H. Stromme
- Jul 01, 2006
ONE of your employees--let's call him Joe Supervisor--is working on a job site where a backhoe is digging the foundation for a new office building. The soil is being loaded into large dump trucks. As you can imagine, the noise level from the backhoe and the trucks is almost deafening. Of course, Joe knows all about the consequence of hearing loss from exposure to noise; that's why he's wearing ear plugs.
How Far Down?
He's standing near the edge of the trench, supervising the dig. A line of dump trucks is waiting to be filled. Joe is facing away from this line of vehicles. Suddenly, one of the trucks starts to back up. It pulled too far forward, and the excavator can't fill it properly. As the truck begins to back up, its reverse signal alarm goes off just as Joe turns and starts to walk behind the truck.
He hears the beeping, and the training he received kicks in. Joe immediately jumps out of the way of the backing vehicle.
The Bell Tolls for Whom?
At the other side of town, another of your employees, Mary, is working on an electrical panel in a manufacturing facility. All of a sudden, a warning bell sounds. Mary is an outside contractor at the plant; she's not sure what the sound means. Has a fire started? Has there been a chemical release? Is the warning bell a tornado alert?
Mary did not receive any training on emergency warning alarms when she arrived at the facility. She has no idea what to do or where to go.
What Does It Say?
Pedro has been working at ABC Company for two years. He speaks some English but can't read English at all. Pedro is walking across an area of the facility that has metal grating over an opening in the floor. His extra pair of ear plugs falls out of his pocket, onto the grating, and through one of the holes. He looks down and can see the package of ear plugs lying on top of a piece of machinery.
He walks down some steps until he's on the same level as the equipment. Pedro notices a sign on the machine, but it's in English, and he can't read it. As he reaches up to grab the ear plugs, the machine starts, pulling Pedro into it. The sign reads, "Stand clear, equipment may start at any time."
The Outcomes
It ended fine for Joe (at least this time), and the jury is still out on what happened to Mary. However, Pedro certainly ended up at the hospital or maybe the morgue.
Preventing Unsafe Conditions
OSHA requires employers to instruct each employee to recognize and avoid unsafe conditions. An effective approach is to train construction employees so they know how vehicle and excavation alarms sound and what to do when they hear them. Then instruct them in the proper signs and markings used on the job site.
With that in mind, let's focus on the types of warning devices found on construction jobsites. The three covered here are:
- vehicle alarms
- evacuation alarms
- signage
Vehicle alarms
Most of us are familiar with the excessive noise of outdoor construction job sites (and inside facilities where construction work is being done). That noise can be a huge detriment to safety: Constant noise causes the brain to tune it out. (It's called selective hearing.) That's why OSHA requires certain equipment to be outfitted with backup alarms. (OSHA calls it a "reverse signal alarm.")
As Joe found out, alarms--and especially backup alarms on construction vehicles--are an important part of the hazard awareness "early warning system."
Motor vehicles
OSHA's construction standard at 29 CFR 1926.601 regulates vehicles used for both highway and off-highway purposes on a job site that is not open to public traffic. It states, "No employer shall use any motor vehicle equipment having an obstructed view to the rear unless the vehicle has a reverse signal alarm audible above the surrounding noise level, or the vehicle is backed up only when an observer signals that it is safe to do so."
OSHA takes this a step further in a Letter of Interpretation (LOI) dated May 27, 2004, where OSHA extrapolates from the words "audible above the surrounding noise level" to imply that the alarm must provide "adequate warning to workers in the path of the vehicle, and to workers walking towards the path of the vehicle in time to avoid contact."
Materials handling equipment
At 1926.602(a)(9)(ii), OSHA states:
No employer shall permit earth moving or compacting equipment which has an obstructed view to the rear to be used in reverse gear unless the equipment has in operation a reverse signal alarm distinguishable from the surrounding noise level or an employee signals that it is safe to do so.
Are these regulations really necessary? In an LOI dated Sept. 27, 2004, OSHA states:
These standards were established because of the pervasive construction hazard of being struck by construction vehicles. Recent OSHA data underlines the importance of protecting against this hazard. In the period 2001-2004, OSHA investigated eight fatal accidents in which a worker was struck by a construction vehicle that was backing up without an operable alarm.
The vehicle or equipment operator can't eliminate the struck-by hazard simply by backing the unit cautiously. The vehicle must have a backup alarm or a spotter must assist the operator.
Keep in mind that the effectiveness of audible alarms tends to diminish over time as employees get accustomed to the noise.
Evacuation Alarms
Remember Mary working on the electrical panel? She heard the warning alarm and didn't know what to do or where to go. Without the proper training, a contractor is at a disadvantage when working on a job site that has specific alarms to designate certain hazards. Some of the distinct alarms could call for evacuation of an area (or sheltering in a safe area) because of a chemical spill, fire, or workplace violence incident.
The complexity and sophistication of the alarm system required depends on the number and size of operations and the associated degree of hazard for a given facility. A small, single-process plant may require only a simple siren to call for evacuations. In a larger, more complex facility, there may be multiple responses (or multiple evacuation routes) that employees must follow. If that's the case, the alarm system should clearly convey the information necessary to allow employees to respond or evacuate in a safe and appropriate manner.
Depending on the facility, communicating the response to a chemical spill may require the following information:
- the location of the release;
- the type of the release (i.e., vapor, gas, liquid);
- the ambient conditions that may affect response or evacuation options; and
- which contingent response or evacuation procedure is to be followed.
The level of training required for employees regarding the alarm system increases directly with the complexity and sophistication of the system. Training would be required to cover how and what the alarm system communicates to employees during an emergency.
A facility, although having an adequate alarm system and found to be in compliance with all of the pertinent OSHA hardware regulations, may not have trained its employees in the proper contingent responses indicated by the alarm system. This would be a deficiency in the required training program--that is, general industry's 1910.1200(h)(3) or 1910.120(q)(6)--and would be cited as such by OSHA.
Signage
The accident that Pedro was involved in is, unfortunately, all too common. Employees often can't read the sign or simply choose to ignore it. However, proper signage can offer some protection against hazards. Signage often consists of symbols and wording that, together, effectively convey the needed information. In this instance, the warning sign didn't prevent Pedro from being injured. Would a symbol on the sign have made a difference?
OSHA's position is that the use of symbol signs only would not meet the requirements of 1910.145. However, symbols can be used in conjunction with English words. It's also important to remember that signs do have limitations. As in Pedro's case, what if the sign is written in a language that the reader doesn't understand?
Not only is the textual portion of a sign or tag important, color is also important to convey a message quickly. Color can communicate and reinforce the message instantaneously. In a "sea" of signs, you can understand why color is so important.
What if the sign that Pedro saw was red in color, had a symbol of a hand getting pinched, and had the words, "Stand clear, equipment may start at any time" on it? It sounds like a good idea, but what about the training?
General Training
OSHA's catch-all for construction training (at 1926.21) requires that employers instruct workers in the recognition and avoidance of unsafe conditions and the regulations that apply that employee. This, in turn, can control or eliminate those hazards or prevent exposure to illness or injury.
Specific Training
OSHA's construction standard has training requirements for specific hazards. Indeed, except for Subpart H, each of the Subparts in 29 CFR 1926 has some training requirements.
A Final Thought
Are you not sure your employees understand what the warning sounds and devices mean? If in doubt, provide training! That's because effective training is the very best way to protect employees from job site hazards.
This article appeared in the July 2006 issue of Occupational Health & Safety.
This article originally appeared in the July 2006 issue of Occupational Health & Safety.