A dishwasher sanitizes only if it reaches 150°F during the final rinse, typically via a sanitize cycle.
- Cleaning removes dirt, but sanitizing kills bacteria; look for NSF/ANSI Standard 184 certification.
- For high-risk items like baby bottles or after illness, use the sanitize cycle; for everyday dishes, regular washing is fine.
How Does a Dishwasher Sanitize Dishes?
Dishwashers sanitize through high-temperature rinsing. The final rinse must reach at least 150°F (65°C) to kill bacteria effectively. Most standard cycles only heat water to around 130°F to 140°F. That lower temperature cleans but does not sanitize. A dedicated sanitize cycle boosts the rinse temperature and often extends the cycle time. Detergent also helps break down food and grease, but heat does the heavy lifting for germ removal.
What Is the Difference Between Cleaning and Sanitizing?
Cleaning removes visible dirt, food, and grease from surfaces. Sanitizing reduces bacteria to safe levels, as defined by public health standards. A dishwasher can clean without sanitizing if the water stays below 150°F. Sanitizing requires both heat and time to denature proteins in microbes. The NSF/ANSI Standard 184 certification verifies a dishwasher's sanitizing capability. Without that certification, you cannot assume sanitization occurs.
Which Dishwasher Settings Actually Sanitize?
Look for a 'Sanitize' or 'Sani' cycle on your machine. This setting typically extends the final rinse and raises water temperature. Some models also use a heated dry option to maintain high heat. Check your owner's manual for the exact temperature and duration. If your dishwasher lacks a sanitize cycle, you can run the pots and pans cycle, which often heats water hotter. Alternatively, use a rinse aid to improve water sheeting, which helps heat reach surfaces.
Does a Dishwasher Kill All Germs, Including Viruses?
No dishwasher can guarantee the elimination of every pathogen. Sanitizing reduces bacteria by 99.999% under controlled conditions, per NSF standards. Viruses like norovirus are more resistant and may survive lower temperatures. The CDC notes that water above 170°F is needed to inactivate some viruses instantly. Most home dishwashers cannot reach that temperature. For high-risk items, consider boiling or using a chemical sanitizer after washing.
When Should You Use the Sanitize Cycle?
Use the sanitize cycle for baby bottles, cutting boards, and utensils used with raw meat. Also, sanitize after someone in your household has been ill. Immune-compromised individuals benefit from sanitized dishes. If you have a well-water system, sanitizing helps reduce microbial contamination. However, frequent sanitizing can increase energy use and wear on dishes. Reserve it for high-risk loads.