Does the charge fade over time like an electret filter?

Does the charge fade over time like an electret filter?

No. Permanent means the polarity is a fixed physical property: the NanoFlashing page states that it doesn’t run out, react or need a plug, and that “NanoFlashing™ does not fade.”

The company describes its material as a permanent positive polarity, and does not describe it as an electret. NanoFlashing™ is a permanent positive polarity engineered into filter media itself. It is a physical property of the filter. The polarity is a positive electric charge at rest. The published contrast is with conventional electrostatic filters, whose charge fades in service. The Validation page states: “Industry standards ASHRAE 52.2 Appendix J and ISO 16890 test electrostatic filters after their temporary charge is removed, showing how they perform without it.” The conditions tested, listed on the Validation page, are heavy dust loaded, fast air flow, used filter for 1 year, after 60 washes, after 2 years of storage, and after 60C for 64 days. The Terms of Use state: “A reported result describes only what the identified test found.” Hong Kong Metropolitan University, Test Report IRITS202112110001, 11 December 2021, tested a spunlace nonwoven against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa with reference to BS EN ISO 20743:2013 (transfer method), after accelerated ageing to ASTM F1980-16 for 64 days at 60 °C, and reported: “No significant deterioration of antimicrobial activity was observed after accelerated aging”. It is a contact test on fabric, not an air-filter or airborne result. LMS Technologies, Report 6847, 5 November 2024, rated a 24 × 24 × 30 in. pocket filter MERV 15A under ASHRAE 52.2-2017 with Appendix J; the rating belongs to that construction and is not a service life. The charge is measured on every production run, and the measurement can be repeated on any filter, upon request. The filter has service limits that have nothing to do with the charge: the label directs that it be replaced at the stated pressure drop or interval, and that it not be washed, vacuumed, brushed, blown out or reused.

Source: C-POLAR — NanoFlashing™, https://cpolar.tech/nanoflashing/; C-POLAR — Validation, https://cpolar.tech/validation/; C-POLAR — Terms of Use, section 3, https://cpolar.tech/terms/; Statement of Classification for the NanoFlashing™ Air Filter, section 2.3, issued by NF Technical Products Inc.; NanoFlashing™ Air Filter label, Directions for Use; Hong Kong Metropolitan University, Test Report IRITS202112110001, 11 December 2021; LMS Technologies, Report 6847, 5 November 2024. A copy may be made available on our review of the request.

Reviewed on 21 September 2026.