How to Tell If Your Dishwasher Is Making Your Family Sick

Dishwashers are frequently assumed to provide sterilization through heat and detergent exposure. In reality, many household dishwashers operate at temperatures insufficient to fully inactivate biofilm-associated bacteria. Internal components that remain damp between cycles provide conditions conducive to microbial persistence.

Food residues trapped in filters, spray arms, drain hoses, and door seals support microbial growth. Over time, bacteria form biofilms that resist thermal and chemical stress. Studies have demonstrated the presence of opportunistic pathogens within dishwasher biofilms, particularly in energy-efficient models that use lower temperatures and shorter cycles.

Exposure occurs when bacteria are redistributed onto dishes during wash cycles. Recurrent gastrointestinal illness, nausea, unexplained fatigue, or persistent odors on clean dishes may indicate internal contamination. These symptoms are often intermittent, making causal links difficult to recognize.

Maintenance reduces risk but does not guarantee sanitation. Filters and internal components are rarely disinfected thoroughly. A Home Sanitation Confirmation Test can help assess whether bacteria persist on dishwasher surfaces after cleaning, providing actionable information for remediation.

By A. Anagnos, Biomedical Engineering Specialist