January 5, 2026 – A concerning product safety incident involving Master flow Drab20x20 HVAC filters manufactured by RCD Corporation has come to light, with reports indicating widespread microbial growth, including mold toxic to humans, within residential heating, ventilation, and air conditioning systems. Incident reports suggest that these product issues are consistently leading to mold breakouts in a significant percentage of homes where the filters are installed.
Product Details
Incident Overview
An incident report filed on December 11, 2025, details a severe safety hazard associated with Master flow Drab20x20 HVAC filters. The report specifically identifies the rampant development of microbial growth, including mold known to be toxic to humans, within HVAC systems where these filters are used. Alarmingly, the report states that product issues with the Master flow Drab20x20 filters are directly responsible for these mold breakouts, occurring “every time in 50% of homes” within HVAC systems. This suggests a systemic flaw in the product design, materials, or manufacturing that creates an environment conducive to harmful microbial proliferation. The high frequency of incidents – affecting half of all homes using the product – points to a significant and widespread risk.
Safety Concerns
The presence of toxic mold in residential HVAC systems, as reported with the Master flow Drab20x20 filters, poses severe and multifaceted safety concerns:
- Immediate Dangers: Exposure to toxic mold can lead to a range of immediate health issues, including severe allergic reactions, respiratory problems (such as coughing, wheezing, shortness of breath, and asthma attacks), skin irritation, eye irritation, and nasal congestion. Individuals with pre-existing respiratory conditions or allergies are particularly vulnerable to acute symptoms.
- Long-Term Risks: Prolonged exposure to toxic mold can result in chronic health problems, including persistent respiratory illnesses, neurological issues, fatigue, headaches, and a compromised immune system. Certain molds produce mycotoxins that can have more severe and lasting systemic effects on the human body.
- Who Might Be Affected: All occupants of affected homes are at risk, but certain populations are particularly susceptible. This includes infants and young children, the elderly, individuals with asthma, allergies, or other respiratory conditions, and those with weakened immune systems. Pets can also suffer adverse health effects from mold exposure.
- Property Damage Potential: Beyond health risks, mold infestations can cause significant property damage. Mold can degrade building materials, including drywall, insulation, wood, and carpets, necessitating costly remediation and repairs. An HVAC system contaminated with mold can itself be damaged, requiring professional cleaning or even replacement of components, leading to substantial financial burden for homeowners. The widespread nature of the problem (50% of homes) suggests potential for widespread property damage.
What Consumers Should Do
If you own or have recently purchased Master flow Drab20x20 HVAC filters, it is crucial to take immediate action:
- Immediate Steps to Take: If you suspect mold growth in your HVAC system (e.g., visible mold near vents, persistent musty odors, or unexplained health symptoms), immediately turn off your HVAC system to prevent further spread of spores. Avoid disturbing visible mold, as this can release more spores into the air.
- How to Check If You Own the Affected Product: Carefully inspect your HVAC filter. Look for the “Master flow” brand name and “Drab20x20” model designation on the filter frame. If you cannot safely access your filter or are unsure, consult with an HVAC professional.
- Prevention Measures (for future use): While this issue appears product-specific, general HVAC maintenance includes regular filter checks and replacements. However, given the nature of this incident, it is strongly recommended to discontinue use of Master flow Drab20x20 filters immediately. Consider alternative filter brands with a strong safety record.
- Reporting Procedures: If you have experienced mold growth or other issues related to Master flow Drab20x20 filters, please report the incident to the U.S. Consumer Product Safety Commission (CPSC) at SaferProducts.gov. Additionally, contact a qualified HVAC professional or mold remediation specialist to inspect and address any existing mold contamination in your home. Document all observations, including photos and videos, and keep records of any related health issues or property damage.
Manufacturer’s Response
No response has been provided by RCD Corporation regarding these serious allegations of microbial growth and toxic mold outbreaks associated with their Master flow Drab20x20 HVAC filters.
Legal Help Available
If you or a loved one has been injured by a defective product or suffered property damage due to a product malfunction, you may be entitled to compensation. The experienced product liability attorneys at Farzan Law understand the complexities of defective product cases and can help you navigate the legal process.
Contact us today for a free consultation: 424-325-3112
Our legal team has successfully represented clients in product liability cases involving defective appliances, automotive defects, medical devices, and consumer products. We work on a contingency fee basis, which means you don’t pay unless we win your case.
Note: This information is based on incident reports provided by the U.S. Consumer Product Safety Commission. If you find information that is incorrect, please contact us immediately so we can correct the post to reflect accurate information.
Disclaimer: The information provided in this post is not intended to be legal or medical advice. This article is based on publicly available incident reports. The incidents mentioned have not necessarily been independently verified or adjudicated.