A burnt plastic smell from a dishwasher is a common household event, usually caused by a small plastic item falling onto the heating element. This raises immediate concerns about the safety and potential toxicity of the resulting smoke and fumes. When plastic is subjected to high temperatures, it undergoes thermal decomposition, releasing a complex mixture of chemicals into the air. Understanding the specific hazards and knowing the proper steps for personal safety and appliance remediation is important for managing this situation.
The Immediate Health Risks of Inhaling Fumes
The primary threat from melted plastic is inhaling toxic pyrolysis products, the chemical byproducts created when heat breaks down the material. These fumes immediately irritate the mucous membranes of the eyes, nose, and throat. Common acute symptoms include a burning sensation in the airways, persistent coughing, and shortness of breath.
The inhalation of these gases can also trigger systemic responses, such as headaches, dizziness, and nausea. Significant exposure, especially to gases like carbon monoxide, can lead to confusion and a rapid escalation of symptoms. Anyone experiencing respiratory distress or persistent neurological symptoms should immediately seek fresh air and call a medical professional or poison control.
Immediate action involves prioritizing ventilation by opening all windows and doors to draw the fumes out. Turn off the dishwasher power at the breaker box to prevent further heating of the residue. Removing yourself and any vulnerable individuals, such as children or those with pre-existing respiratory conditions, from the contaminated area is the most effective safety measure.
Understanding Which Plastics Pose the Greatest Hazard
The level of hazard depends significantly on the chemical composition of the plastic that melted. Many kitchen plastics are Polypropylene (PP) or Polyethylene (PE), which are hydrocarbons that release less toxic combustion products, such as carbon monoxide and various aldehydes, when heated. While noxious, the fumes from these common materials are generally less chemically corrosive than others.
Polyvinyl Chloride (PVC) poses a much greater risk because it contains chlorine atoms. When PVC is subjected to high heat, it releases highly corrosive hydrogen chloride gas, which forms hydrochloric acid upon contact with moisture in the respiratory tract. The thermal decomposition of chlorinated plastics like PVC can also generate dioxins and furans, which are persistent organic pollutants.
Polystyrene (PS), often used in disposable containers, releases styrene gas when it melts. Styrene is a known irritant that can cause neurological symptoms like dizziness and fatigue. The presence of nitrogen in certain plastics, such as nylon items, can lead to the release of hydrogen cyanide, a highly potent toxic gas.
Cleaning and Safely Decontaminating Your Dishwasher
Before cleanup, ensure the dishwasher is completely cool and the power supply remains disconnected at the circuit breaker. Proper ventilation is necessary, so keep windows open and use fans to circulate air out of the kitchen area. This prevents further exposure to residual fumes or contact with a hot heating element.
The physical removal of the melted plastic residue is the first step in decontamination. If the plastic is still soft, allow it to cool and harden fully, perhaps by placing a bag of ice directly on the residue to make it brittle. Once hardened, the material can be gently chipped or scraped off the heating element and tub floor using a wooden or plastic utensil to avoid damaging the appliance.
After removing the solid residue, the dishwasher interior needs a thorough cleaning to neutralize lingering chemical odors and soot. A paste made from baking soda and water can be applied directly to stained areas to absorb odors and remove fine residue particles. White vinegar is an effective natural deodorizer and can be used to wipe down all interior surfaces, including the racks and walls, as its mild acidity helps break down residues.
Once the interior surfaces have been manually cleaned, run at least two empty cycles on the hottest setting. For the first cycle, place a cup of white vinegar in a dishwasher-safe container on the top rack to further sanitize and deodorize the machine. Follow this with a second empty cycle using a standard dishwasher detergent to ensure all cleaning agents and residual fumes are flushed from the system before placing dishes back inside.