How NLR Restoration safely remediated high-risk silica dust contamination using engineering controls, H-Class HEPA filtration, PAPR respiratory protection and documented verification. Silica dust has emerged as one of Australia’s most significant workplace health hazards. Found in concrete, engineered stone, bricks, tiles and many other construction materials, respirable crystalline silica (RCS) consists of microscopic particles capable of penetrating deep into the lungs when inhaled. Across Queensland, employers are subject to increasingly stringent obligations to identify, assess and control silica dust risks. Compliance now extends well beyond personal protective equipment (PPE), requiring documented risk assessments, engineering controls, air monitoring and, where applicable, health monitoring. When a large commercial facility in South East Queensland discovered extensive white dust contamination throughout its plant rooms, they engaged NLR Restoration to undertake a specialist remediation project. The result was a carefully planned silica dust cleanup that demonstrated how high-risk contamination should be managed safely, professionally and in accordance with current workplace health and safety requirements. Why Respirable Crystalline Silica Is So Dangerous Respirable crystalline silica particles are typically less than 10 microns in diameter, making them invisible to the naked eye and small enough to bypass the body’s natural defence mechanisms. Repeated or uncontrolled exposure has been associated with serious illnesses including: Silicosis Lung cancer Chronic obstructive pulmonary disease (COPD) Kidney disease Because these particles cannot be seen once airborne, facilities that appear visually clean may still present a significant inhalation hazard if contamination has not been properly assessed and controlled. Commercial Silica Dust Cleanup in Queensland This project involved far more than routine cleaning. Dust contamination had accumulated across: Mechanical plant HVAC ducting Pipework Electrical switchboards Building services equipment Initial real-time airborne particulate monitoring identified extremely elevated dust concentrations during disturbance activities, confirming the need for comprehensive engineering controls and strict respiratory protection throughout the remediation. The presence of extensive electrical infrastructure created additional complexity, limiting where wet cleaning methods could safely be used and requiring alternative cleaning techniques around live equipment. Before work commenced, the project required detailed planning, including revised Safe Work Method Statements (SWMS), respirator management procedures, air monitoring protocols and documented silica risk controls developed in collaboration with the client. Understanding Queensland’s Silica Compliance Requirements Queensland businesses have significant obligations when managing silica dust risks. Depending on the nature of the work, these obligations may include: Conducting air monitoring where exposure may approach applicable Workplace Exposure Standards (WES). Implementing engineering controls to eliminate or minimise airborne dust. Providing suitable respiratory protective equipment. Maintaining documented silica risk control procedures. Providing health monitoring where required under the legislation. For this project, NLR Restoration worked closely with the client to develop and refine documentation before remediation commenced. Multiple revisions of the SWMS and risk controls ensured the planned works accurately reflected site conditions and the proposed control measures. Effective compliance is not simply paperwork—it is a documented process of planning, consultation and verification. NLR’s Structured Remediation Approach Although there is currently no dedicated IICRC Standard specifically addressing silica remediation, the project adopted recognised contamination control principles consistent with industry best practice, including engineering controls, HEPA filtration, systematic cleaning, contamination containment and verification monitoring. Containment and Engineering Controls Preventing dust migration was the first priority. Containment barriers were installed around the affected work areas, HVAC openings were sealed, and industrial H-Class HEPA air scrubbers were positioned to establish negative air pressure within the containment. Maintaining negative pressure ensured disturbed airborne particles remained inside the work area and were continuously captured through high-efficiency filtration rather than escaping into occupied areas of the facility. Caption: Temporary containment established to prevent migration of airborne silica dust. Systematic HEPA Cleaning Once containment had been established, technicians followed a structured top-to-bottom cleaning methodology. The remediation sequence included: HEPA vacuuming ceilings, ductwork and overhead services Cleaning plant equipment and structural surfaces Cleaning wall surfaces Final HEPA vacuuming and cleaning of floor areas Industrial H-Class vacuum cleaners compliant with AS/NZS 60335.2.69 were used throughout the project to safely capture fine respirable dust. Where electrical equipment permitted, damp microfibre wiping was undertaken to minimise dust generation. Around sensitive electrical infrastructure, HEPA vacuuming combined with controlled dry wiping provided the safest cleaning approach. Waste materials were HEPA vacuumed before removal, double-bagged within heavy-duty waste bags and sealed prior to licensed disposal. PAPR Respirators for Silica Dust Cleanup Protecting workers remained a critical component of the project. Every technician wore: Disposable protective coveralls Gloves Safety boots Eye protection Fit-tested Powered Air Purifying Respirators (PAPRs) fitted with P3 particulate filters Under NLR’s respiratory protection procedures, each respirator undergoes pre-use airflow verification, daily cleaning and disinfection, scheduled maintenance and annual quantitative fit testing in accordance with AS/NZS 1715. Workers are also required to remain clean-shaven where the respirator seals against the face to maintain effective respiratory protection. During the project, NLR transitioned from older Sundström PAPRs to newer CleanSpace units, providing longer battery life, reduced operator fatigue and improved productivity during extended work periods. Silica Dust Air Monitoring and Verification Air monitoring formed an essential component of the remediation process. Throughout the project, calibrated real-time particle monitoring equipment was used to observe airborne particulate concentrations both inside and outside the containment zone. Monitoring confirmed that engineering controls effectively limited dust migration beyond the work area while providing continual feedback throughout cleaning operations. Following completion of remediation and continued HEPA air filtration, verification monitoring demonstrated a substantial reduction in airborne particulate concentrations, supporting safe reoccupation of the affected areas. Surface cleanliness was also visually verified before containment removal to confirm that no visible settled dust remained. The monitoring records formed part of the documented project handover provided to the client. Overcoming Site-Specific Challenges Every silica remediation project presents unique technical challenges. At this facility, live electrical equipment limited the use of wet cleaning methods in certain locations. Working alongside the client’s electricians, equipment was isolated wherever practical to maximise safe cleaning options while protecting critical infrastructure. Accessing overhead services also required specialised equipment. Extension poles fitted to H-Class HEPA vacuum systems enabled technicians to safely clean ductwork,
