OSHA Noise Limits & Workplace Hearing Protection Guide

Walk through a busy manufacturing facility, and you'll hear machines running, forklifts moving materials, and workers using power tools. For employees who spend hours around this noise, the risk to their hearing can build up over time. The tricky part is that hearing damage doesn't always happen suddenly. Workers may not realize there's a problem until they start having trouble hearing conversations or notice ringing in their ears.

For safety managers, understanding OSHA noise exposure limits is a practical first step toward protecting employees and creating a safer workplace. Implementing effective workplace hearing protection measures can also help reduce the risk of noise-related hearing loss.

The short answer: Under OSHA's general industry standard, employers must implement a hearing conservation program when employee noise exposure reaches or exceeds an 8-hour time-weighted average of 85 decibels (dBA). Hearing protectors must be provided at no cost at this level, and certain employees are required to wear them. When exposure exceeds the permissible exposure limit of 90 dBA over eight hours, feasible engineering or administrative controls are required, with hearing protection used as necessary to meet the standard.

1. What Are OSHA's Workplace Noise Exposure Limits?

OSHA measures workplace noise in decibels, usually written as dBA. This measurement accounts for how the human ear responds to different sound frequencies.

For general industry, two numbers are especially important: 85 dBA and 90 dBA. They serve different purposes, and knowing the difference helps employers decide when to take action.

These limits refer to average noise exposure over time. A quick reading taken beside a machine won't necessarily tell you how much noise an employee experiences throughout an entire shift.

OSHA also uses a 5-decibel exchange rate for its general industry standard. In simple terms, as the noise level increases by 5 dBA, the allowable exposure time is cut in half.

For example, the standard allows eight hours at 90 dBA, four hours at 95 dBA, and two hours at 100 dBA. These are exposure limits, not recommended noise levels for everyday work.

NIOSH, the National Institute for Occupational Safety and Health, recommends a more protective limit of 85 dBA averaged over eight hours, using a 3-decibel exchange rate. This is a recommendation rather than the same legally enforceable limit used by OSHA's general industry standard.

2. When Is Workplace Hearing Protection Required?

The answer depends on how much noise employees experience, how long they're exposed, and which OSHA requirements apply to their work.

Under OSHA's general industry standard, employers must provide suitable hearing protectors at no cost when employee exposure reaches or exceeds an 8-hour time-weighted average of 85 dBA. The standard also requires certain employees to wear hearing protection, including employees exposed at or above the action level who have not yet established a baseline audiogram or who have experienced a standard threshold shift.

A standard threshold shift is a change in hearing ability identified through audiometric testing.

Some workplaces need a closer look at noise exposure than others. Common examples include:

• Manufacturing facilities: Employees work around presses, grinders, cutting machines, and production lines.
• Construction sites: Workers use jackhammers, power saws, drills, and heavy equipment.
• Warehouses and distribution centers: Forklifts, conveyor systems, and loading operations create noise throughout the day.
• Automotive workshops: Air compressors, impact wrenches, and other tools can produce high sound levels.
• Maintenance departments: Workers may encounter loud machinery while repairing or testing equipment.

Working in one of these environments doesn't automatically mean every employee needs the same hearing protection. Employers should assess actual noise exposure and determine which protective measures are appropriate.

There are also everyday warning signs worth paying attention to. If employees regularly raise their voices to talk to someone standing an arm's length away, the area may be too noisy. Ringing in the ears or difficulty hearing after work can also signal a potential problem.

Don't rely on these signs alone, though. Proper noise monitoring is the best way to understand employee exposure.

3. What Is the Difference Between OSHA's Action Level and PEL?

The action level and permissible exposure limit are often confused, but they have different purposes.

The 85 dBA action level triggers hearing conservation program requirements under OSHA's general industry standard. Depending on the applicable requirements, the program includes noise monitoring, hearing protection, audiometric testing, employee training, and evaluation of hearing protectors.

The 90 dBA permissible exposure limit (PEL) is the general industry standard's eight-hour exposure limit. When employee exposure exceeds the applicable limits, employers must use feasible engineering or administrative controls. Hearing protection must also be provided and used as necessary to meet the standard.

Consider a manufacturing facility where employees spend most of their shift near a production line. Noise monitoring shows that one employee's average exposure is 87 dBA over eight hours. Although this is below the general industry PEL, it reaches the action level, so the employer must meet the applicable hearing conservation requirements.

Now consider another employee whose eight-hour average exposure is 95 dBA. That exposure exceeds the general industry PEL, so the employer must take appropriate steps to reduce noise exposure and meet the standard.

The key point is simple: employers shouldn't wait until noise reaches 90 dBA before taking hearing risks seriously.

4. How Can Employers Measure Noise Exposure?

Before choosing hearing protection or changing work procedures, employers need to understand where noise comes from and how much exposure employees receive during a normal shift.

Noise levels can change throughout the day. A machine may run quietly during setup but become much louder during production. An employee who moves between several work areas may also experience different noise levels throughout the shift.

Here are three common tools used to assess workplace noise:

• Sound level meters: Measure sound levels at a particular location and time.
• Noise dosimeters: Track an employee's noise exposure over a period, often across a full shift.
• Noise measurement apps: Help screen sound levels and identify areas that may need further assessment.

For example, a safety manager could walk through a warehouse during a busy shift and note areas where forklifts, conveyors, and loading activities create the most noise. That initial check can help identify where more detailed monitoring may be needed.

The NIOSH sound level meter app can help with initial screening and identifying potentially noisy areas. However, a phone app reading alone shouldn't be treated as proof that a workplace meets OSHA requirements. Formal exposure assessments may require appropriate monitoring equipment and qualified assistance.

When reviewing workplace noise, safety managers should consider:

1. Which employees work near noisy equipment.
2. Which tasks create the highest sound levels.
3. How long employees spend in each noisy area.
4. Whether multiple noise sources contribute to total exposure.
5. Whether existing controls and hearing protectors provide adequate protection.

Keep the relevant monitoring records and reassess exposure when equipment, work processes, or employee assignments change.

5. What Types of Hearing Protection Should Employers Consider?

Choosing hearing protection isn't just about picking a product with a high noise reduction rating. Employees need equipment that fits properly, works with their other PPE, and suits the tasks they perform.

Three common options are earplugs, earmuffs, and combinations of hearing protectors.

Earplugs

Earplugs fit inside the ear canal and are useful in many industrial settings. They're compact and easy to carry, making them a practical option for employees who move between work areas.

The catch is fit. Earplugs must be inserted correctly to provide their intended level of protection. Employers should make sure workers know how to use and care for them.

Earmuffs

Earmuffs cover the outer ears and can be easier for some employees to put on and remove. They may be useful in workplaces where workers need to take hearing protection on and off throughout the day.

However, earmuffs need to work with other required PPE. Safety glasses, hard hats, and other equipment can interfere with the seal if the combination isn't suitable.

Combined hearing protection

Some high-noise environments may require employees to use earplugs and earmuffs together. Whether this is necessary depends on the noise exposure and the protection provided by the selected devices.

A higher noise reduction rating doesn't automatically make a product the best choice for every job. Employers should evaluate the actual exposure and select protectors that provide adequate attenuation without creating other safety concerns.

OSHA's general industry standard also requires employers to provide a choice of suitable hearing protectors, train employees in their use and care, ensure proper initial fitting, and supervise correct use.

To explore available workplace hearing protection solutions, employers can review options suited to their facility's needs.

6. Can Employers Reduce Noise Without Relying Only on PPE?

Hearing protection plays an important role in workplace safety, but it isn't the only way to manage noise. Reducing noise at its source can help protect several employees at once and may make the work environment more comfortable.

Imagine a manufacturing manager notices that one machine is much louder than the equipment around it. Before asking everyone nearby to wear additional PPE, the manager can investigate whether worn parts, poor maintenance, or the machine's design contribute to the problem.

Depending on the situation, possible improvements include:

• Engineering controls: Maintain equipment, install suitable noise barriers or enclosures, and consider quieter machinery.
• Administrative controls: Organize work to limit exposure time when practical and consistent with safety requirements.
• Workplace layout: Increase distance from noise sources where possible and restrict unnecessary access to high-noise areas.
• Hearing conservation: Provide required training, monitoring, hearing protection, and audiometric testing.

The right approach depends on the equipment, the noise source, and how employees work around it. Moving workers between noisy areas won't necessarily solve the problem if their combined exposure remains excessive.

It's also worth reviewing controls after equipment or production changes. A work area that was previously acceptable may become much noisier after a new machine is installed or production increases.

7. Workplace Hearing Protection Checklist for Safety Managers

A simple checklist makes it easier to review your current hearing protection practices and identify areas that need attention.

Use the following questions during a workplace safety review:

• Have you identified work areas and tasks that may generate hazardous noise?
• Have you arranged appropriate noise monitoring when employee exposure may reach the action level?
• Have you determined whether your facility meets the applicable hearing conservation program requirements?
• Are suitable hearing protectors provided at no cost when required?
• Do employees know how to fit, use, clean, and replace their hearing protectors?
• Have employees received the required training?
• Are noise monitoring and hearing conservation records maintained as required?
• Do you reassess exposure after relevant equipment or process changes?

This checklist is a starting point, not a substitute for a compliance review. Requirements can differ by industry and work activity, so employers should confirm which OSHA standard and any additional state-plan requirements apply to their facility.

Frequently Asked Questions

1. At what noise level does OSHA require hearing protection?

Under OSHA's general industry standard, hearing protectors must be made available at no cost when employee exposure reaches or exceeds an eight-hour time-weighted average of 85 dBA. Whether an employee must wear them depends on the applicable requirements and individual circumstances. Excessive exposure above the permissible limit also requires appropriate controls.

2. Is 85 dBA the OSHA noise exposure limit?

Not exactly. For general industry, 85 dBA over eight hours is the action level that triggers hearing conservation program requirements. The permissible exposure limit is 90 dBA over eight hours. NIOSH recommends limiting exposure to 85 dBA over eight hours to reduce the risk of noise-induced hearing loss.

3. Does OSHA require hearing protection at 90 dBA?

OSHA requires feasible engineering or administrative controls when employee noise exposure exceeds the applicable permissible exposure limits. Hearing protection must be provided and used when necessary to meet the standard. Employers shouldn't assume that simply providing earplugs resolves excessive exposure.

4. Can a phone app determine whether a workplace meets OSHA requirements?

A sound measurement app can help screen an area and identify possible noise hazards. However, a phone reading may not accurately represent an employee's full-shift exposure or establish regulatory compliance. Employers should use appropriate monitoring methods and qualified assistance when needed.

5. How often should a workplace review its hearing protection program?

Employers should reassess their program when noise levels, equipment, work processes, or employee assignments change in ways that could affect exposure or the adequacy of hearing protectors. They must also meet applicable monitoring, training, audiometric testing, and recordkeeping requirements.

Next Step

Workplace noise can be easy to overlook when everyone is focused on getting the job done. Start by identifying noisy areas, checking employee exposure, and making sure your team has suitable hearing protection. Reviewing your current setup can also help you spot equipment or work practices that may need attention. UniFirst First Aid + Safety can help your facility explore hearing protection options and identify areas for further review.

Get a hearing protection & noise review for your facility