Following the breakage of two to three mercury sphygmomanometers in a clinic (confidential client), HDS performed a preliminary assessment of the contamination extent and established a physico-chemical decontamination protocol, including vapor monitoring using a Jerome J405 analyzer. The work successfully reduced air concentrations to below 3.0 µg/m³, allowing for a safe resumption of activities.
The breakage of mercury-containing equipment during a move released mercury into a stack of cardboard boxes. Such events may go undetected initially, leading to the involuntary spread of mercury micro-droplets through foot traffic, impacting porous materials (ceramic joints, textiles, wood, etc.) and increasing the potential for mercury vapor retention and re-emission. By the time a spill is noticed, containment is critical; access must be restricted immediately to protect occupants and prevent further spreading.
Before HDS Environment arrived, on-site personnel attempted to recover the free mercury using non-specialized means (e.g., domestic vacuums) or by washing contaminated equipment with water, which inadvertently spread the contamination further. Additionally, the building's mechanical ventilation remained operational, facilitating the diffusion of mercury vapors into areas not initially affected by the spill.
A healthcare environment serving potentially vulnerable populations requires a more conservative re-occupancy threshold than standard industrial settings. Consequently, a specific end-of-work criterion and a mercury vapor measurement protocol were established in collaboration with the Regional Public Health Department (Direction de santé publique) using a proactive prevention approach.
HDS conducted a preliminary assessment to confirm the scope of contamination (location of micro-droplets, affected materials, ventilation conditions) and establish a tailored strategy. Initial emphasis was placed on mercury recovery, surface decontamination, and the disposal of contaminated materials and equipment. This strategy focused immediately on vapor reduction, thereby minimizing subsequent issues related to the building's mechanical ventilation systems.
The intervention combined consecutive physico-chemical decontamination cycles: (i) recovery of free mercury and cleaning cycles on accessible surfaces; (ii) vacuuming with specialized vacuums (five-stage filtration, including a mercury-specific carbon filter); and (iii) chemical decontamination using dedicated reagents to oxidize and stabilize the mercury (reducing volatility and facilitating cleanup). Throughout the process, mercury vapor levels were monitored and documented using a Jerome J405.
Contaminated residual materials generated by the spill and cleanup were secured in 210L drums, which were then sealed, decontaminated (exterior), and labeled for pickup by a specialized hazardous waste company. The final site inspection was conducted alongside worker representatives so they could personally verify that the Jerome J405 measurements met the established re-occupancy criteria. HDS Environment documented the entire process in a detailed report, meeting the requirements of both public health authorities and insurers.
With cutting-edge expertise in occupational hygiene and mercury spill management, HDS Environment places the protection of occupants and workers at the heart of its strategy. The approach is based on rigorous risk assessment, specialized methods adapted to the situation, and clear re-occupancy criteria, ensuring a safe return to work.
Vapor control, the application of specialized methods tailored to the spill's specificities, and strict OHS oversight reduced exposure risks despite high initial levels and porous materials that can trap mercury. Occupants were able to reintegrate into the building based on a scientific approach and documented, clear criteria.
The intervention resulted in a comprehensive file: strategy, boundaries, personnel protection, measuring instruments with calibration certificates, compiled data, work sequence, and hazardous waste management. This traceability supports the client’s due diligence and facilitates communication with stakeholders, such as public health departments, unions, or insurers.
Industrial hygiene services provided by HDS for a northern mining company: assessment of living and production facilities to ensure compliance.
HDS reduces the environmental impact of road de-icing salts for a public agency: audits of 10 CEMS, water sampling, and action plans.
