Contractor Hazard Communication Toolbox Talk

Many jobsites involve multiple employers working side by side. Contractors, subcontractors, and host employers may all bring hazardous chemicals onto the site. Effective hazard communication ensures everyone understands the chemical hazards present, knows how to access Safety Data Sheets (SDSs), follows labeling requirements, and understands the procedures for safely working around hazardous substances.

This toolbox talk reviews the responsibilities of contractors and host employers for communicating chemical hazards and coordinating safe work practices on multi-employer worksites.

Why This Matters

• Workers may be exposed to hazardous chemicals brought onto the site by another employer.
• Sharing hazard information helps prevent chemical exposures, fires, and incompatible chemical mixing.
• Clear communication ensures all workers understand emergency procedures.
• Coordinated hazard communication reduces confusion and improves jobsite safety.
• Proper communication supports compliance with Hazard Communication requirements.

Common Hazards

• Contractors introducing hazardous chemicals without notifying the host employer.
• Missing or inaccessible Safety Data Sheets (SDSs).
• Unlabeled or improperly labeled chemical containers.
• Incompatible chemicals stored or used in close proximity.
• Workers unaware of nearby chemical hazards.
• Poor coordination during chemical spills or emergency response.
• Changes in work activities that introduce new chemical hazards.
• Failure to communicate restricted work areas or ventilation requirements.

Safety Checklist

Before Work Begins

• Inform the host employer of any hazardous chemicals your company will bring onto the site.
• Review the hazardous chemicals already present at the worksite.
• Ensure current Safety Data Sheets (SDSs) are available and accessible for all hazardous chemicals used by your company.
• Verify all chemical containers are properly labeled.
• Coordinate storage locations and ensure incompatible chemicals are separated.
• Review emergency procedures, spill response, and reporting requirements with all affected personnel.

During Work

• Communicate any new chemical hazards introduced during the project.
• Keep chemical containers properly labeled and closed when not in use.
• Follow site-specific Hazard Communication procedures and access restrictions.
• Notify affected employers if work activities could create additional chemical exposure risks.
• Report chemical spills, leaks, damaged containers, or missing labels immediately.
• Update hazard information whenever work conditions or chemicals change.

Crew Talking Points

• What hazardous chemicals are being used by our company today?
• Have all affected contractors been informed of those hazards?
• Where are the Safety Data Sheets (SDSs) located?
• How should chemical spills or exposures be reported?
• Who should be notified before introducing a new hazardous chemical onto the site?
• Speak up immediately if you discover an unlabeled container, missing SDS, or an uncommunicated chemical hazard.

Stop Work If

• Hazardous chemicals have not been communicated to affected employers.
• Required Safety Data Sheets (SDSs) are unavailable.
• Chemical containers are unlabeled or improperly labeled.
• Incompatible chemicals are stored or used without proper controls.
• A chemical spill or release cannot be safely managed.
• You are unsure of the hazards associated with chemicals being used on the site.

Final Reminder

Hazard communication is everyone's responsibility on a multi-employer worksite. Share information about hazardous chemicals, maintain current Safety Data Sheets, ensure every container is properly labeled, and coordinate with other employers whenever chemical hazards change. Good communication protects every worker on the jobsite.