Who Is Responsible for Vendor Employee Hearing Conservation? OSHA’s Rules Explained

Across manufacturing, logistics, energy, aviation, and industrial services, more vendors are embedding full time employees inside customer facilities. These workers often perform the same tasks, use the same equipment, and face the same noise hazards as the host employer’s workforce. Yet when OSHA’s Hearing Conservation Program (HCP) requirements under 29 CFR 1910.95 apply, the responsibility is not always obvious. The short answer is simple: the vendor is responsible for providing the full Hearing Conservation Program for its own employees, and the host employer is generally responsible for controlling workplace hazards within the facility, including hazardous noise, and for communicating those hazards to employers whose workers are exposed. The same principles generally apply to staffing agencies, contractors, maintenance providers, resident vendors, and other employers whose workers perform services inside another employer’s facility. This structure comes from OSHA’s multi-employer worksite policy, and it shapes how citations are issued during inspections.

OSHA’s Split Responsibility Model

OSHA considers situations involving multiple employers under its Multi-Employer Citation Policy (CPL 02-00-124). Although widely used in construction, OSHA makes clear that this policy applies to general industry as well. In any environment where employees of different employers work side by side, OSHA places responsibility into two categories: the employing employer and the host (controlling and exposing) employer.

1. The Employing Employer: What the Vendor Owns

This is the company listed on the worker’s W-2. The vendor is responsible for maintaining the complete Hearing Conservation Program for its own employees, as required by 29 CFR 1910.95. This includes:

• Ensuring its employees’ noise exposures are evaluated, either through its own monitoring or by relying on representative monitoring data from the host employer when that data is valid and applicable
• Enrollment of employees exposed at or above 85 dBA TWA
• Baseline and annual audiometric testing
• Employee training at least annually
• Providing appropriate hearing protection
• Standard Threshold Shift follow up
• Recordkeeping and documentation

OSHA recommends, but does not require, earplug fit testing. The agency highlights this in the OSHA Technical Manual Section III Chapter 5, explaining that fit testing can verify the actual attenuation workers receive. Many employers use fit testing because it reduces the likelihood of STS cases.

OSHA’s multi-employer policy generally places responsibility on each employer for protecting its own employees, even when they work at another employer’s facility.

2. The Host Employer: What the Customer Owns

The host employer controls the facility and the physical environment where the vendor’s employees work. Responsibilities include:

• Maintaining noise levels as low as feasible
• Allowing access for vendor noise measurements
• Communicating known or newly identified noise hazards
• Maintaining machinery and equipment that may contribute to hazardous noise levels
• Alerting vendors when noise conditions change

If hazardous noise exists in the facility and the host employer does not communicate or control those conditions, OSHA can issue citations.

Why Many Host Employers Test Vendor Employees Anyway

If the vendor fails to perform testing like it should, or if the vendor’s results ever conflict with a later hearing loss claim, the host employer has its own independent audiogram record to point to.

Host employers that test vendor employees gain:

• Proof the exposure was managed: Independent audiograms show the host took the noise hazard seriously for everyone in the facility, not just its own W-2 employees
• A defense against vendor gaps: If the vendor never performed baseline or annual testing, the host still has records demonstrating due diligence
• A second data set for disputes: When a workers’ comp or liability claim attributes hearing loss to the host’s facility, the host can compare its own serial audiograms against the vendor’s and against the claim
• Earlier detection of problems: If a vendor employee shows a threshold shift, the host can flag it to the vendor before it becomes a recordable injury inside the host’s facility

Testing vendor employees does not shift the regulatory burden. The vendor still owns the HCP under 1910.95. But an independent record gives the host leverage in contract enforcement and a documented defense if the responsibility question ever ends up in front of OSHA or a court.

3. During OSHA Inspections Involving Hearing Conservation or Hearing Loss

When a Standard Threshold Shift occurs or a hearing related injury is recorded, OSHA may issue citations to one or both employers.

The vendor may be cited for failure to:

• Enroll affected employees in the HCP
• Conduct required audiograms
• Provide hearing protection
• Train employees
• Follow up on STS cases
• Maintain accurate records

The host employer may be cited for failure to:

• Control or maintain noise levels
• Communicate hazardous noise areas
• Provide monitoring access
• Notify vendors about noise changes
• Correct noise sources that elevate exposure

OSHA may cite one or multiple employers depending on each employer’s role under the Multi-Employer Citation Policy. Both employers can face citations when both contributed to the conditions.

If you need the simplest possible version of the rule: vendors are responsible for the Hearing Conservation Program for their own employees, host employers are generally responsible for controlling and communicating noise hazards in the facility, and both employers may be cited. Every contract negotiation, service agreement, and site orientation should start from that split.

A Practical Example: 20 Technicians in a Stamping Plant

A maintenance services vendor provides 20 technicians who work full time inside a large manufacturing plant. The plant operates stamping presses, conveyors, and grinders that often produce noise levels between 88 and 96 dBA. The vendor’s technicians work throughout the facility, often side by side with the host employer’s permanent employees.

Vendor Responsibilities in This Scenario

The vendor must:

• Conduct noise exposure monitoring for its employees, or obtain reliable dosimetry data from the host employer
• Enroll all technicians exposed at or above 85 dBA TWA in the HCP
• Perform baseline audiograms before or soon after assignment, followed by annual audiograms
• Provide hearing protection and ensure employees know how to insert earplugs correctly
• Provide training on hearing risks and proper use of hearing protection
• Consider earplug fit testing as a best practice, consistent with OSHA guidance
• Document all results, maintain OSHA aligned records, and manage STS follow up

If OSHA found that the vendor failed to provide audiograms or did not enroll employees despite known exposures, the vendor would be cited.

Host Employer Responsibilities in This Scenario

The host employer must:

• Communicate that the production floor operates between 88 and 96 dBA
• Allow the vendor to perform noise monitoring activities
• Maintain stamping machines and grinders to avoid preventable noise increases
• Clearly identify and communicate hearing protection areas where appropriate
• Notify the vendor when production changes or machine repairs alter noise exposure

If OSHA found that the host ignored elevated noise levels or failed to warn the vendor about unusually loud areas, the host could be cited.

Likely OSHA Outcome

If an OSHA inspection followed an STS in this example, both employers could face citations. The vendor may be cited for gaps in its HCP, and the host employer may be cited for creating or failing to control the noise hazard. This example illustrates how multi-employer responsibilities function in real facilities.

Where Soundtrace Fits In

Soundtrace helps both vendors and host employers maintain compliance.

For Vendors

A complete, OSHA aligned Hearing Conservation Program that includes:

• Fast baseline and annual audiograms using portable equipment
• Connected noise monitoring and exposure tracking
• Automatic STS detection and follow up workflows
• Optional earplug fit testing workflows that align with OSHA guidance
• Cloud based documentation across all customer sites

For Host Employers

Improved visibility and shared accountability through:

• Real time exposure insights for embedded vendor teams
• Shared reporting that demonstrates effective hazard communication
• Documentation support during audits
• Centralized recordkeeping that validates multi-employer compliance

Vendors gain a turnkey HCP. Hosts strengthen their safety posture and reduce risk.

Frequently Asked Questions