Is compliance with the OSHA hearing conservation standard enough to ensure that employees will not suffer from hearing loss due to their exposures at work? In many cases, hearing health experts say, the answer is no, prompting them to advocate occupational safety and health measures that focus on prevention rather than simply compliance.
"For the companies that have proactive programs, that do more than the rule requires, [their employees] tend to have hearing loss that is consistent with aging but not due to noise exposure," says John Franks, who heads NIOSH's hearing conservation group. "Is compliance adequate? The answer is no. Compliance is the framework for building a prevention program."
No one claims that it is easy to keep a hearing conservation program focused on prevention rather than compliance when every safety and health expenditure is being carefully scrutinized. "There is a very backward trend among industries to just do compliance and nothing else," one veteran industrial audiologist says. "I think that is unfortunate."
In the face of such pressures, safety and health experts are paying more attention to metrics in general, and hearing conservation is no exception.
"Health and safety people are being required to justify their programs on a rolling basis in a business context, so the whole issue of just doing something for compliance and going through the motions doesn't count anymore," says Lee Hager, an audiologist with James Anderson and Associates Inc., Lansing, Mich. "Upper-level managers want to know how do we stack up with our competition, how do we stack up within our company, how are we spending our money, are we being effective? As a result, measures of program effectiveness are increasingly important."
John Mulhausen, manager, corporate industrial hygiene at 3M Co., St. Paul, says there is a general interest in metrics as a way to "impose some discipline" on programs such as hearing conservation, to make them routine business processes that are self-regulating rather than requiring a champion to make sure things happen.
"You want to have some system of defining expectations, monitoring in a routine way progress on those expectations and then providing feedback to the organization on how they are doing," Mulhausen says, adding that company managers want data available that "reassures them that we have our pulse on the state of industrial hygiene in the organization and that systems are in place to help manage it."
For most companies, says audiologist Deanna Meinke of Associates in Acoustics, Greeley, Colo., the measurement that is usually focused on is standard threshold shift (STS), which measures changes in hearing acuity at different frequencies. According to OSHA enforcement policy, employers must record work-related shifts in hearing of an average of 25 dB or more at 2,000, 3,000 and 4,000 hertz in either ear.
In January 2001, OSHA proposed changing this trigger for a recordable injury to 10 dB. In July, however, OSHA said it was reconsidering the change because "Congress intended the recordkeeping system to capture nonminor injuries and illnesses. OSHA is reconsidering the finding that a 10 dB shift in hearing acuity represents such a health condition."
"The STS drives everything for industry," Meinke observes. "When we're sitting at 25 dB, there are a whole lot of people who aren't getting attention who should be getting some intervention sooner, but that recordability [trigger] drives decisions and economics."
Meinke says the use of STS is not a bad idea in itself; the problems stem more from how it is used. "If we do things right, if we test during a work shift and find a temporary change and intervene, then the STS isn't too late. But very seldom do companies get the retest within 30 days and look at the use of hearing protection. So in reality, most of the time when we see the STS, it is permanent."
Meinke prefers to use STS data as an early warning indicator for intervention with an employee. "What I do with some of my clients is to send out a list of people who are approaching the 10 db STS. Maybe they're sitting at an average change of 7 or 8. Let's go check their hearing protectors and work habits, and just see if there is anything else we should be doing before it gets to that point."
Going Beyond the Minimum
Solutia, the chemical business that spun off from Monsanto nearly five years ago, has continued with a hearing conservation policy that exceeds the OSHA standard. Rather than use 85 dB time-weighted average (TWA) as the trigger for including employees in its hearing conservation program, Solutia includes employees exposed to 80 dB TWA and provides hearing protection at 85 dBA.
Steve Hacker, Solutia's industrial hygiene manager, says the company has operations such as high-speed nylon production where high noise levels are generated, so the company employs a variety of tools to protect workers' hearing.
"Our project review process includes a formal checklist, and part of that deals with noise sources," he explains. "We try to limit those to 85 TWA for eight hours." Where work shifts last 10 hours, the target for equipment is 83 dB; for 12-hour shifts, it is 82 dB. He adds, "If you can't find equipment, then there is a variance procedure that must be completed."
Because some of Solutia's facilities were built in the 1950s or earlier, Hacker also seeks out engineering solutions that can be retrofitted. In some cases, he notes, these engineering controls - reduced pressure on air nozzles, small mufflers on pneumatic lines and replacing chain drives with belt drives - are relatively inexpensive.
Solutia conducts noise monitoring on a regular basis. "In production areas, we do sound level surveys at least every other year, and we'll do dosimetry annually, depending on how many employees are involved and what the previous exposures were," Hacker says. "At times, we have found where previous engineering controls have just worn out or they're not being used properly, and then that's a good time to identify those and go back and fix them."
Hacker places a high value on the company's efforts to train and monitor employees to make sure they understand the hearing conservation rule, the potential health effects of noise and the proper use of hearing protection. Solutia uses a computer-based program for its annual hearing conservation training because of the flexibility it provides to workers. Coupled with that, hearing protection is included in personal protective equipment checklists that are part of the behavioral safety program. Solutia also conducts self-audits to make sure employees are wearing hearing protection and that engineering controls are operating properly.
Hacker says Solutia encourages employees to take hearing protection home when they are doing something loud. "It's important to make sure that they know that it doesn't matter if you lose your hearing from an on-the-job or off-the-job exposure - you're still damaged. It is not going to get any better.
"We're also doing corporate audits, depending on the risks at a particular facility, on a three- to five-year basis. We look at the written programs, and we do records review, including recordability issues. We have a database where we maintain their audiometric information, compare it to the baseline annually and make sure they do the follow-up. We do a thorough records review. We also go out into the area and ask questions about their training and knowledge, just to verify that if it says their name is on the list, that they have been trained."
Last fall, Solutia completed an epidemiological study. Hacker was pleased to discover that the company population, as a whole, was suffering less hearing loss than would be expected based on standard projections arising from its noise levels. He had the epidemiologist present the findings to the plant industrial staffs through an Internet conference. For facilities that had good results, Hacker used the opportunity to praise their efforts. Where plants had higher-than-normal potential recordables, he urged them to re-energize their efforts. In both cases, Solutia urged the industrial hygiene staffs to share the results with managers and employees.
As did other experts contacted, Hacker believes that younger workers are more concerned about their health than their older counterparts and more inclined to take steps to protect their hearing.
Hearing conservation experts say there are many metrics that can be applied to hearing conservation programs to measure their effectiveness. They can relate to monitoring, training, engineering, hearing protection and other aspects of a program.
"If we look at the percent of the work force that is overexposed to noise, in order to track it from year to year, you need a regular noise survey that is conducted in a consistent format and a consistent procedure. That then provides an important index," Hager says. "How do we know if our noise abatement projects are doing any good? Well, we can look at the percentage of the work force that is overexposed, and maybe that can give us some insight.
"Some of our clients look at the percentage of the work force trained as a function of the percentage of the work force overexposed. If our noise survey tells us that we have 500 people overexposed, but we have trained 1,000 people, is that a good thing or a bad thing? If we have only trained 200 people, but we were supposed to train 500, does that tell us something? There are other measures to assess the effectiveness of different pieces of the program."
NIOSH's Franks says behavioral observations are an important element in measuring program effectiveness. "If you have an area where hearing protection is required, you need to make sure it is being used. One of the ways to do so is to make sure people are trained in its use and use it well and understand why they are using it." Removing hearing protection for just 15 minutes out of an eight-hour shift, for example, can cut protection effectiveness in half.
Franks says companies need to use audiometric data not just to notify workers when there is a hearing loss, but also as a tool to let them know that their good work practices are paying off. By providing feedback with audiometric data that is within normal variance (plus or minus 5 dB), the company shows noise-exposed workers that "they are doing their part well" and helps involve them in the process of hearing loss prevention.
Meinke stresses that, along with program metrics, companies need to assure the quality and the regularity of the data they are collecting. "A lot of companies put a lot of effort into having a hearing conservation program and testing people regularly, but they don't ever look to see if their equipment is calibrated or if they missed people for the last five years that fell off their list somehow."
In the end, many hearing health experts say, the key is to make sure employers and employees understand how important the ability to hear is to our lives and that noise-induced hearing loss is preventable. "We take our hearing for granted and never recognize its value until it's lost," Meinke says. "We run into that same societal view when we talk to companies. They don't really recognize the cost in terms of lost communication and the safety risks of workers not hearing and communicating."
Sidebar: Monitoring Audiometry and Recordkeeping
- Has the audiometric technician been adequately trained, certified and recertified as necessary?
- Do on-the-job observations of the technicians indicate that they perform a thorough and valid audiometric test, instruct and consult the
- employee effectively, and keep appropriate records?
- Are records adequate?
- Are follow-up actions documented?
- Are hearing threshold levels reasonably consistent from test to test? If not, are the reasons for inconsistencies investigated promptly?
- Are the annual test results compared to the baseline to identify the presence of an OSHA standard threshold shift (STS)?
- Is the annual incidence of STS greater than a few percent? If so, are problem areas pinpointed and remedial steps taken?
- Are audiometric trends (deteriorations) being identified, both in individuals and in groups of employees? (NIOSH recommends no more than 5 percent of workers showing 15 dB Significant Threshold Shift, same ear, same frequency.)
- Do records show that appropriate audiometer calibration procedures have been followed?
- Is there documentation showing that the background sound levels in the audiometer room were low enough to permit valid testing?
- Are the results of audiometric tests being communicated to supervisors and managers, as well as to employees?
- Has corrective action been taken if the rate of no-shows for audiometric test appointments is more than about 5 percent?
- Are employees incurring STS notified in writing within at least 21 days? (NIOSH recommends immediate notification if retest shows 15 dB Significant Threshold Shift, same ear, same frequency.)
Source: "Hearing Conservation Program Evaluation Checklist," NIOSH