That trusty blue and yellow can of WD-40 sits in nearly every garage and tool box across America. We reach for it without a second thought when something squeaks or sticks. But many homeowners are unknowingly creating serious hazards with this common household product. What looks like a simple solution could actually be putting your family, home, and health at risk when used incorrectly. Understanding when and where not to use this popular spray might just save you from a dangerous situation.
Using WD-40 near open flames or heat sources
Many people spray WD-40 without checking their surroundings first, creating a potentially deadly situation. The product is highly flammable, containing petroleum-based hydrocarbons that can ignite instantly when they come into contact with fire. Think about your water heater, furnace, or even a nearby candle – these common household items produce enough heat to transform that helpful spray into a dangerous fireball. The aerosol nature of WD-40 makes it particularly hazardous as it creates a fine mist that can travel through the air and reach heat sources you might not even realize are nearby.
The risk extends beyond the immediate spray area, as the vapors can linger in the air for some time afterward. Many people have experienced close calls when using WD-40 to loosen parts on hot engines or near working appliances. The product’s label clearly warns against using it near heat sources, but in a rush to fix something quickly, these critical safety warnings are often overlooked. Always ensure you’re using WD-40 in a well-ventilated space, away from any potential ignition sources, and give the area time to clear of vapors before introducing any heat or flame to the environment.
Applying WD-40 to your vehicle’s brake system
One of the most dangerous mistakes happens when people try to fix squeaky brakes with a quick spray of WD-40. This seemingly simple fix creates an extremely hazardous situation that could lead to complete brake failure. WD-40 reduces friction – which is exactly what you don’t want on your braking system. Your brakes rely on friction to slow and stop your vehicle. When WD-40 coats brake pads, rotors, or other components, it drastically reduces their ability to grip and create the necessary friction for stopping, potentially leading to a serious accident the next time you need to stop quickly.
The damage isn’t temporary either. Once applied to brake components, WD-40 can be difficult to completely remove, creating an ongoing safety issue. The petroleum-based lubricant can also damage rubber components in the braking system, leading to leaks or failures. If you’re experiencing squeaky brakes, the proper solution is to have them inspected by a qualified mechanic who can determine if they need cleaning, lubricating with the correct brake-specific products, or replacement. Brake noise usually indicates an issue that needs professional attention, not a quick spray of a general-purpose product that could put your life at risk.
Spraying WD-40 in poorly ventilated spaces
Using WD-40 in enclosed spaces like small closets, crawl spaces, or tight corners creates a serious health risk many users overlook. The product releases volatile organic compounds (VOCs) and petroleum distillates that can cause respiratory irritation when inhaled. In a poorly ventilated area, these chemicals quickly concentrate in the air you’re breathing. Regular exposure can lead to symptoms including headaches, dizziness, and nausea. Many users report feeling lightheaded after using WD-40 in confined spaces but fail to connect these symptoms to the product, continuing the dangerous practice.
The risk becomes greater for people with existing respiratory conditions like asthma or COPD, as the chemical fumes can trigger attacks or worsen symptoms. Even for healthy individuals, breathing these concentrated fumes for extended periods may lead to more serious health issues. When using WD-40, always ensure adequate ventilation by opening windows and doors, using fans to circulate air, or wearing appropriate respiratory protection if working in an area that can’t be properly ventilated. Better yet, consider taking the item outside when possible before applying the product to minimize your exposure to these potentially harmful fumes.
Using WD-40 on items that contact food
A surprisingly common but dangerous mistake is using WD-40 on kitchen tools, grills, or other surfaces that come into contact with food. The product is not food-safe and contains chemicals that should never be ingested. Some homeowners spray it on can openers to keep them working smoothly, use it to loosen stuck parts on blenders or mixers, or even apply it to grill grates to prevent sticking. These applications create a serious risk of chemical contamination in your food, potentially exposing your family to harmful substances with every meal prepared using these contaminated utensils or surfaces.
The health risks stem from the petroleum-based solvents and other ingredients in WD-40 that can transfer to food and subsequently be ingested. These chemicals are not meant for consumption and may cause digestive issues or other health problems if eaten. For kitchen applications, always opt for food-grade lubricants specifically designed for culinary equipment. These products are tested and approved for incidental food contact, making them a safe alternative for keeping your kitchen tools in working order. Similarly, for grills and outdoor cooking equipment, use food-safe options like food-grade lubricants designed specifically for these applications.
WD-40 and certain plastic materials don’t mix
Many homeowners make the mistake of using WD-40 on plastic items without realizing it can cause serious damage to certain types of plastic. Specifically, polycarbonate and clear polystyrene plastics can crack, cloud, or completely break down when exposed to the chemicals in WD-40. This reaction happens because the petroleum distillates in the product attack the molecular structure of these plastics. The damage isn’t always immediately visible either – sometimes it takes hours or days for the plastic to show signs of degradation, leading users to think the application was safe when it actually wasn’t.
This mistake becomes particularly problematic when dealing with expensive or critical plastic components in electronics, appliances, or safety equipment. For example, using WD-40 to lubricate plastic parts in a computer, camera, or even safety goggles can compromise their integrity and functionality. Before applying WD-40 to any plastic surface, check the material compatibility or test in an inconspicuous area first. Better yet, look for lubricants specifically formulated for use with plastics, such as silicone-based products that won’t cause degradation. These alternatives provide the lubrication you need without risking damage to your plastic items.
Storing WD-40 cans improperly creates explosion risks
The way you store your WD-40 could be setting up a dangerous situation in your home. As a pressurized aerosol can, WD-40 is particularly sensitive to heat and can explode if exposed to high temperatures. Many homeowners make the critical mistake of storing these cans in garages or sheds that can reach extreme temperatures during summer months. When temperatures climb above 120°F (49°C), the pressure inside the can increases significantly, potentially causing the container to rupture or explode. This explosion risk isn’t just theoretical – numerous cases of aerosol can explosions occur each year, sometimes resulting in property damage or injuries.
Another storage mistake involves keeping WD-40 near water heaters, furnaces, or other heat-generating appliances inside homes or garages. Even if the ambient temperature is normal, the radiant heat from these appliances can raise the temperature of nearby cans to dangerous levels. To store WD-40 safely, keep it in a cool, dry place away from direct sunlight and heat sources. Never leave it in a car during hot weather, and be mindful of seasonal temperature changes in storage areas. If you notice any rusting, denting, or damage to the can, dispose of it properly according to local regulations for hazardous materials rather than risk using a compromised container.
Long-term exposure risks many users ignore
A serious mistake many regular WD-40 users make is ignoring the potential long-term health effects of repeated exposure. While occasional use with proper precautions poses minimal risk, people who use the product frequently without adequate protection may be exposing themselves to harmful compounds. Research suggests that prolonged, heavy exposure to petroleum distillates and other chemicals found in products like WD-40 could potentially contribute to more serious health issues. DIY enthusiasts and professionals who use the product daily are at particular risk if they aren’t taking proper safety measures.
The danger increases when users regularly spray the product without gloves, allowing it to contact their skin directly. Though temporary exposure is generally not harmful, regular skin contact can lead to dermatitis and other skin problems as the chemicals strip away natural oils. Similarly, frequent inhalation without proper ventilation or respiratory protection can irritate the respiratory tract. To minimize these risks, always wear nitrile gloves when handling WD-40, work in well-ventilated areas, consider using a mask for extensive applications, and wash hands thoroughly after use. For frequent users, consider alternatives like non-toxic lubricants for applications where they would work equally well.
Ignoring the dangers of aerosol propellants
Many users focus solely on the lubricant properties of WD-40 while completely overlooking the hazards associated with its delivery system. The aerosol propellant used in WD-40 cans has its own set of risks independent of the lubricant itself. These propellants are highly pressurized gases that can cause frostbite if sprayed directly on skin from close range. The fine mist created by aerosol sprays is also more easily inhaled than liquid applications, increasing respiratory exposure to the chemicals. Many people spray WD-40 with their face too close to the application area, breathing in far more of the aerosolized product than they realize.
There have also been safety concerns raised about the aerosol cans themselves. According to a lawsuit filed against the U.S. Department of Transportation, some WD-40 cans manufactured with carbon dioxide propellant may be susceptible to permanent deformation, potentially creating a safety hazard. While these claims are disputed, they highlight the importance of inspecting any aerosol can for damage before use. If you need the benefits of WD-40 without the aerosol risks, consider using the non-aerosol options like WD-40 trigger spray or similar products that deliver the same formulation without the pressurized propellant risks.
That helpful can of WD-40 certainly has its place in your toolkit, but using it wisely requires understanding its limitations and potential dangers. By avoiding these common mistakes and taking proper precautions, you can continue to benefit from this versatile product while keeping yourself and your family safe. Remember that sometimes the right solution isn’t reaching for what’s familiar, but rather selecting the proper tool or product specifically designed for your particular need.
