The classification confusion with Health Canada is what currently delays ZenGUARD filters, and there is nothing Zentek can do until they put their heads and give us a classification...
Here’s a clear, non-speculative overview of the types of technical and safety data Health Canada typically asks for when evaluating novel antimicrobial coatings and advanced materials (including graphene-based coatings) for HVAC filters.
This applies whether the product ends up classified as a pest control product (PMRA) or a medical device (Medical Devices Regulations) — the specific data requirements change slightly between pathways, but the themes are the same.
? 1. Material Characterization Health Canada needs to know exactly what the coating is.
Typical requests: - Chemical composition
(elemental makeup, purity, additives, binders).
- Nanomaterial characterization
If graphene or graphene oxide is used:
- sheet size distribution
- layer count
- surface area
- functional groups
- potential impurities (e.g., metals)
- Stability on the substrate
How tightly does the coating adhere to the filter fibres?
This helps them assess whether particles could detach or degrade.
? 2. Particle Shedding and Inhalation Safety This is a major focus for any coated HVAC filter.
Health Canada typically evaluates: - Shedding tests under airflow
(simulated HVAC flow rates, clean vs dusty environments).
- Particle size distribution of what gets released.
Smaller particles (<1 µm) are more relevant for inhalation.
- Airborne concentration during “worst-case” use.
- Toxicological assessment of inhaled particles:
- acute inhalation toxicity
- repeated exposure
- respiratory irritation
- lung burden and clearance
For nanomaterials like graphene, inhalation toxicology data is usually required even if shedding is extremely low.
? 3. Antimicrobial Efficacy Evidence If antimicrobial claims are made (e.g., reduces microbial load on the filter), Health Canada requires:
- Standardized antimicrobial tests, such as:
- ISO 20743 (antibacterial on textiles)
- ASTM E2149 (dynamic contact killing)
- AATCC 100 (antimicrobial textiles)
- Efficacy under real airflow — not just static lab tests.
- Durability: Does efficacy persist over the entire filter lifespan?
- Spectrum of organisms tested
(bacteria, fungi, viruses depending on claims).
For HVAC filters, regulators focus heavily on realistic operational conditions, not lab-only results.
? 4. Human Exposure Risk Assessment Health Canada wants to understand all possible exposure routes:
They look at: - Inhalation (primary concern)
- Dermal exposure (for installers)
- Accidental ingestion/hand contact (low, but assessed)
Includes:
- Estimated daily exposure levels
- Comparison to toxicology NOAELs (No Observed Adverse Effect Levels)
- Vulnerable populations (children, elderly, respiratory illness patients)
? 5. Environmental Safety Data If classified under PMRA, this section becomes very detailed.
Typical requirements:
- Persistence and degradation of the coating
- Behavior of nanoparticles in water, soil, air
- Acute/chronic toxicity to:
- aquatic organisms
- soil organisms
- plants
- beneficial microbes
- Waste disposal considerations
(e.g., landfill release of graphene particles)
? 6. Manufacturing and Quality Control Health Canada usually wants:
- Batch consistency data
- Quality-control specifications
- Contaminants and residuals testing
- Stability of the coated filter over time
- Shelf-life data
- Storage condition studies
This ensures the coating applied in production matches what was tested.
? 7. Safety of the Filter as a Whole Product HVAC filters introduce additional review areas:
- Airflow impact
(Does the coating change resistance or performance?)
- Pressure drop stability over time
- Thermal or electrical safety
(especially for powered or conductive coatings)
- Fire safety
(coatings must not increase flammability)
?? 8. Claims Review — Health Canada Is Strict About This Regulators examine:
- Wording of antimicrobial claims
(must be proven, cannot imply disease prevention unless proven)
- Whether the coating affects air quality, infection control, or disease transmission
- Any implied therapeutic claims (which would force the product into medical device regulations)
Summary: What Health Canada Usually Needs Here’s the quick checklist of what they commonly require:
Safety - Particle shedding studies
- Inhalation toxicology
- Durability & adhesion
- Installer exposure safety
- Environmental impact
Efficacy - Antimicrobial testing under realistic airflow
- Long-term durability and performance
Product Performance - HVAC airflow effects
- Pressure drop
- Filter lifespan and safety tests
Regulatory Classification Evidence - Clear justification of whether it is:
- a pest control product, or
- a medical device, or
- a treated article
This classification confusion is what currently delays ZenGUARD filters. |
