Dishwasher detective: exposing the truth about plastic and melting

The convenience of dishwashers is undeniable, but a lingering question remains: can dishwashers melt plastic? This concern is particularly relevant for parents, renters, and anyone who relies on plastic items for daily use. Understanding the potential risks associated with dishwashing plastics is crucial to protect both your belongings and your health.

Heat Sensitivity of Plastics

The ability of a plastic item to withstand the heat of a dishwasher depends on its composition and thickness. Some plastics, such as polyethylene (PE) and polypropylene (PP), have relatively high melting points and can tolerate dishwasher temperatures without melting. However, other plastics, such as polystyrene (PS) and polyvinyl chloride (PVC), have lower melting points and are more likely to deform or melt in the dishwasher.

Temperature and Cycle Settings

The temperature of the water used in a dishwasher can vary depending on the model and cycle setting. Most dishwashers have a “normal” or “regular” cycle that operates at a temperature of around 140-150°F (60-65°C). However, some dishwashers also offer a “sanitize” or “high-temperature” cycle that operates at a higher temperature of around 165-175°F (74-79°C).

Types of Plastic Items Suitable for Dishwashers

Not all plastic items are dishwasher-safe. To determine if a plastic item is suitable for the dishwasher, look for the following symbols:

• Dishwasher-safe symbol: This symbol is an image of a glass with a fork and knife inside and a rectangle at the bottom.
• Top-rack only symbol: This symbol indicates that the plastic item can be placed on the top rack of the dishwasher, which experiences lower temperatures.
• Hand-wash only symbol: This symbol indicates that the plastic item should be washed by hand.

Precautions for Dishwashing Plastics

Even if a plastic item is labeled as dishwasher-safe, it’s important to take the following precautions:

• Avoid overloading the dishwasher: Overloading can obstruct the flow of water and heat, increasing the risk of melting.
• Use the right detergent: Use a dishwasher detergent specifically formulated for plastics. Avoid using abrasive cleaners or detergents that contain bleach.
• Place plastic items securely: Securely place plastic items in the dishwasher to prevent them from moving around and contacting the heating element.
• Remove plastic items promptly: Once the dishwasher cycle is complete, remove plastic items promptly to prevent them from being exposed to residual heat.

Consequences of Melting Plastic

If a plastic item melts in the dishwasher, it can cause the following problems:

• Damage to the dishwasher: Melted plastic can stick to the dishwasher’s heating element or other components, causing damage.
• Health risks: Melted plastic can release harmful chemicals into the dishwasher water, which can be ingested or inhaled.
• Fire hazard: In extreme cases, melted plastic can ignite and cause a fire.

Alternative Cleaning Methods for Plastics

If you’re concerned about the potential risks of dishwashing plastics, there are alternative cleaning methods you can consider:

• Hand-washing: Hand-washing plastic items in warm, soapy water is always a safe option.
• Microwave sterilization: Some plastics, such as polypropylene, can be sterilized in the microwave using a microwave-safe container.
• Steam cleaning: Steam cleaning is an effective way to clean and disinfect plastic items without using harsh chemicals.

Final Note: Dishwasher Safety for Plastics

While dishwashers can be a convenient way to clean plastic items, it’s important to proceed with caution. By understanding the heat sensitivity of plastics, following proper precautions, and using alternative cleaning methods when necessary, you can avoid the risks associated with melting plastic in the dishwasher.

FAQ

Q: Can all plastics melt in the dishwasher?
A: No, some plastics, such as polyethylene and polypropylene, have high melting points and can withstand dishwasher temperatures.

Q: What is the safest way to wash plastic items in the dishwasher?
A: Place plastic items securely on the top rack of the dishwasher, use a dishwasher detergent formulated for plastics, and remove items promptly after the cycle is complete.

Q: What are the signs that a plastic item has melted in the dishwasher?
A: Look for warping, discoloration, or a sticky residue on the plastic item or the dishwasher components.

Q: What should I do if a plastic item melts in the dishwasher?
A: Unplug the dishwasher and allow it to cool completely. Remove the melted plastic and any debris from the dishwasher. Contact a qualified appliance repair technician if necessary.

Q: Can I use bleach to clean plastic items in the dishwasher?
A: No, bleach can damage plastics and make them more susceptible to melting.