Clean Air Acts

Jeff Charlton, Environmental Hygienist and Principal Consultant at Building Forensics explains why a specialist approach is required to secure safe ventilation in buildings

Indoor air quality has become one of the most discussed issues in modern facilities management. Yet many buildings that proudly display environmental certifications still fail to deliver genuinely healthy environments for their occupants.

The clearest indicators of poor indoor air quality and the associated return on any investment in improving air quality are human behaviour.

Facilities managers and human resources departments increasingly observe patterns of absenteeism associated with building occupancy. The phenomenon sometimes described as “Friday absenteeism” or late-week fatigue has been reported in many workplaces. Employees may experience headaches, fatigue, respiratory irritation or cognitive impairment that improves after time away from the building.

Environmental investigations increasingly show that ventilation failures, humidity imbalance, microbial contamination or chemical exposure can contribute significantly to these symptoms.

When HR data is reviewed alongside building conditions, patterns often emerge that point directly to environmental performance issues. Occupants often become an early warning system, highlighting building problems long before technical inspections identify their source.

MEASURING COMPLIANCE

Environmental certification schemes such as BREEAM and LEED have improved awareness of sustainability, ventilation and energy efficiency in building design.

However, their indoor air quality requirements typically focus on a relatively small number of measurable pollutants, including carbon monoxide, formaldehyde, nitrogen dioxide and particulate matter. These indicators are useful, but they represent only a small portion of the environmental factors affecting occupant health.

Building-related illness rarely results from a single contaminant. In practice, it is usually linked to the interaction of several issues, including ventilation performance, moisture intrusion, microbial growth, chemical emissions from materials and poor hygiene within mechanical systems.

This creates a significant gap between certification compliance and the real performance of operational buildings.

HIDDEN COMPLEXITY OF INDOOR ENVIRONMENTS

Modern buildings contain thousands of chemical and biological compounds originating from construction materials, furnishings, cleaning products, electronics and outdoor pollution sources such as traffic emissions.

Many construction materials rely heavily on adhesives, coatings, plastics and synthetic fabrics. These materials can release volatile organic compounds (VOCs) for months or even years after installation.

Moisture intrusion introduces another layer of complexity. Damp materials can support microbial growth that produces spores, fragments and microbial VOCs rarely considered in routine air-quality testing.

Ventilation systems are designed to control these risks, yet they frequently become part of the problem. Poorly maintained air handling units, contaminated ductwork and neglected plenum spaces can accumulate dust, microorganisms and chemical residues. Once disturbed or recirculated, these contaminants may spread throughout the building.

In large commercial properties, HVAC systems effectively become the lungs of the building. If they are contaminated or poorly maintained, they may distribute pollutants faster than they remove them.

In many buildings we inspect, ductwork that appears visually clean from access panels can still contain significant contamination deeper within the system or inside plenum spaces. These areas are rarely inspected during routine maintenance but can play a major role in redistributing contaminants.

CLOSING THE MAINTENANCE GAPS

Routine maintenance of ventilation systems is essential, but the standards governing inspection and cleaning often fail to address the scale of contamination that develops over time.

Ventilation duct cleaning is frequently carried out to satisfy visual cleanliness standards rather than to reduce microbial or chemical contamination. Incredibly, sanitation may still be judged by the thickness of visible deposits rather than meaningful environmental measurements.

Air-handling units are sometimes disinfected using chemical agents without consideration of the residues or biological fragments left behind when microorganisms are killed. The result is that buildings may technically comply with maintenance schedules while still exposing occupants to complex mixtures of biological and chemical contaminants.

These problems rarely appear during routine inspections because contaminants usually travel through airflow pathways rather than remaining visible on surfaces. The most significant drivers of indoor contamination are airflow patterns, pressure differentials and mechanical circulation within the building.

EMERGING RISKS

Indoor air quality is no longer limited to comfort and productivity as FMs must also consider emerging environmental risks. Buildings are not passive shelters. They can trap contaminants, redistribute them through ventilation systems and expose occupants repeatedly over time.

In events involving toxic smoke, biological contamination or industrial accidents, mechanical ventilation systems may become the primary pathway through which hazards spread.

Emerging technologies are also introducing new challenges. Lithium-ion battery fires associated with electric vehicles and energy storage systems can release toxic gases, heavy metal particles, and dense smoke that can spread rapidly through buildings.

Once thermal runaway begins, these fires are extremely difficult to control and may produce contamination long after the initial event. These developments highlight the growing importance of airflow management, ventilation hygiene and contingency planning within facilities management.

INDUSTRY STANDARD ISSUES

A further issue is how many building and maintenance standards are developed. Committees responsible for writing standards often include contractors, equipment manufacturers and service providers.

This can mean that standards reflect operational practice or equipment capability, rather than the long-term health interests of building occupants.

Compliance, therefore, should never be assumed to guarantee a healthy building environment – independent assessment and critical evaluation (especially around the human behaviour being seen) remain essential.

PREVENTATIVE BUILDING HEALTH

The most effective approach to indoor air quality is preventative rather than reactive. Instead of responding only after complaints arise, facilities managers can identify environmental risks early and address them before they affect occupants.

Important steps include:

• Independent environmental inspections beyond routine maintenance.
• Monitoring airflow, humidity and ventilation performance.
• Improving hygiene standards within ventilation systems.
• Identifying chemical emission sources within buildings.
• Integrating occupant feedback and HR data into building management.
• Preparing for emerging environmental hazards.

The objective is not to create alarm but to recognise that buildings are dynamic environments in which air movement, materials, and human activity interact continuously.

When these factors are managed properly, organisations often see tangible business benefits including improved productivity, reduced absenteeism, lower maintenance costs and healthier workplaces.