The hum of the overhead lighting. The rattle of the nearby train heading down its tracks. The continual hammering at the construction site next door. As time passes, these noises become tolerable – even to the point of seemingly being nonexistent.
Human brains have the unique ability to become immune to prolonged sound, pushing it into the background, a phenomenon known as “sensory gating.” Our ears, however, still feel the damaging effects, and for those in noisy manufacturing environments, prolonged exposure can be dangerous.
To protect employees – a business most important asset – it’s important to understand how to keep them safe from loud, prolonged noises on the shop floor. Fortunately, OSHA has laid out guidelines in regard to hearing protection. Beyond OSHA’s regulations, product manufacturers design tools that adhere to the agency’s guidelines and multiple organizations and companies offer tips that can further protect employees’ hearing.
When product manufacturers design tools that adhere to OSHA’s hearing protection guidelines, employers can better safeguard their employees from harmful work-related noise.
Good guidelines
Despite the fact that humans can seemingly adapt to prolonged noise, loud sounds can, in extreme cases, rupture the eardrum and, in other cases, cause tinnitus, a ringing or buzzing sound in the ears and head. Either outcome is unwelcome, especially if the effects become permanent.
In OSHA Standard 1910.95, employers will find guidelines as to how to deal with occupational noise exposure. OSHA mandates hearing protection if a certain decibel spike or decibel level is maintained over a specific period time.
The standard places harmful noise exposure as equal or exceeding 85 decibels over an eight-hour timeframe. In those situations, employers must administer a “continuing, effective hearing conservation program,” which includes decibel testing, monitoring, education and the provision of personal protective equipment (PPE).
OSHA also lays out the decibel levels that employers should be concerned about when employees are exposed for periods less than eight hours. As an example, while 85 decibels are considered a concern over an eight-hour timeframe, being exposed to 95 decibels for four hours should also be a concern. These levels are outlined in the standard’s Table G-16.
“When employees are subjected to sound exceeding those listed in Table G-16, feasible administrative or engineering controls shall be utilized,” OSHA states. “If such controls fail to reduce sound levels within the levels of Table G-16, [PPE] shall be provided and used to reduce sound levels within the levels of the table.”
In addition to assessing decibel levels, continually testing those levels through thorough record keeping, inspection and program evaluation, specific products are being developed to keep emitted decibel levels low.
Deliberate designs
Equipment manufacturers are incredibly aware of the damaging effects that loud tools can have on operators. In response, they have developed products that are safer for operators to use on a continual basis. Many pneumatic power tools, for example, have silencers built into them that serve to muffle the noise. But power tools aren’t the only products to receive new noise-abating designs.
Grinding wheels, too, have received special design treatments to keep emitted decibels as low as possible. Pferd’s Whisper grinding wheel is one of those products.
“Through its patented design, the Whispercreates noticeably less vibration and significantly less noise than conventional grinding wheels,” says Pferd’s marketing manager, Maria Cartier. “The noise exposure is reduced by up to 12 decibels, representing a reduction of more than 90 percent.”
As Cartier relayed, it’s the Whisper’s unique layered design that allows such a significant reduction in noise. Incorporating the safety measure, however, has not been done at the expense of productivity. The layered construction yields less vibration and noise, but also promises fast stock removal rates and excellent service life compared to other traditional grinding wheels.
According to Pferd, “it’s estimated that for every dollar a company spends on health and safety in the workplace, they see a return on investment of about $3 through the reduction of worker’s compensation claims, lower insurance costs, less downtime and sick days, and reduced turnover rates.”
Although specially engineered products, such as the Whisper, may cost a bit more, the tradeoffs are quite significant. For every employee that uses products designed to reduce the amount of noise they’re exposed to, businesses can achieve savings related to their health and safety, potential workman’s compensation claims and the lost time associated with those incidents.
Proper PPE
As outlined in the OSHA standard on occupational hearing loss, the provision of PPE is one of the first lines of defense for companies that determine employees are being exposed to harmful noise. Often, PPE comes in the form of earplugs or earmuffs. When earplugs are employed, it’s important to ensure they’ve been properly placed in the ear. If not, loud noise will still be able to infiltrate the ear canal.
Proper placement is not always assured. During this year’s Manufacturing Day events, Pferd invited high school students to the company facility to give them a chance to visit the lab and see products in action. During the visit, the brush product manager instructed the students to use earplugs and then asked them if they could hear him speaking over the machines. When responding that they could hear him loud and clear, he realized that the students had placed the earplugs in the wrong way.
The product manager quickly told the students how to insert their earplugs for maximum protection. First, he explained that the top of the ear should be pulled up and out to enlarge the opening to the ear canal. With clean hands, he said, squeeze and roll the earplug with the thumb and forefinger and insert it into the ear. If any part of the earplug is sticking out, he said to try inserting it again.
Whether it’s customers using its products or students visiting its manufacturing facility, Pferd stresses the need for hearing protection.
In situations where multiple attempts are unsuccessful, it’s recommended to consult the earplug manufacturer’s instructions for additional instructions or earplugs sizes. Or, employees can use another form of PPE, such as earmuffs.
As with the Whisper grinding wheel, using equipment that creates less noise can help. Pferd has other products designed specifically with hearing protection for the operator in mind as well. The company also focuses on teaching customers about hearing protection – even if it means not using a specialized Pferd product.
As an example, there are several applications where a coated abrasive disc could perform as well or better than a bonded grinding wheel, but with a drastic reduction in noise. In those instances, Pferd fully supports any decision that’s made with the operator’s hearing safety in mind.
