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Does WD40 Harm Plastic? | It Depends

I recently wanted to remove a sticker from a plastic pot and wanted to use WD40 to help speed up the process. I wanted to know if it might damage the plastic, so I did some testing and research, and this is what I learned.

When applied to certain types of plastic, WD40 will slowly disintegrate and discolor the exposed surface. If left for a prolonged period, WD40 may begin breaking down the chemical structure. Crystalline plastics are generally safe, while amorphous plastics are not.

Examples of plastic products to not use WD40 on:

  • Cutlery
  • Baby Bottles
  • Smoke Detector Housing
  • DVD Cases

I learned that flower pots are usually made from crystalline plastic, polypropylene to be exact, so it was safe to use WD40 on it.

Now, let’s cover the subject a bit further.

Mitigating Damage from WD40

Spraying WD40 on a Blue Plastic Chair

WD40’s low viscosity, cleaning, and degreasing composition will inevitably cause deep penetration into plastic. Although it may also be used to clean surfaces covered with dirt, grease, and even grime, WD40 will leave excess oil streaks on plastic which can be difficult to remove.

If untreated, the plastic surface will get damaged over time, and if left unattended, it may very well cause irreparable damage–leaving the plastic section to be repaired or possibly entirely replaced.

If an accidental excess of WD40 has been applied to amorphous plastic, follow the following steps below thoroughly to remove as much of the solution as possible:

  1. With a clean and dry cloth or paper towel, wipe as much solution from the surface, including any cracks and especially areas where the WD40 may become stagnant.
  2. Using dishwasher liquid, apply directly to the surface and begin massaging into the area.
  3. When the desired area is fully covered, dilute the same dishwasher liquid with water and wash off until the soap is completely washed away.
  4. Allow the area to air dry completely.
  5. Check for any remaining WD40 residue and repeat steps 1-4 if necessary.

What Is the Best Lubricant for Plastic?

The safest lubricants to use on plastic are any mineral-oil-based lubricants that consist of silicone or Polytetrafluoroethylene (PTFEE). Depending on what the application is being used for, if a water-repellent effect is desired while obtaining maximum lubrication, silicone spray, like this kind from Amazon, is the better choice. It is affordable and available at most home-improvement stores.

However, for exceptional balance, the most recommended plastic lubricant is PFAE lubricant. They withstand extreme temperatures while lubricating plastic and adhering to the surface. At a higher cost, these lubricants are reserved for more complex projects which require more refined products. They may be found at specialized stores that carry commercial-type applications.

Related 6 Handy Alternatives to WD40.

Safety and Storage Tips

When storing WD40 in an enclosed space, it is recommended to place it into a fire-retardant bin or at a minimum, away from areas that contain open flames.

Minimal exposure to WD40 is mostly harmless. However, for accidental skin contact, thoroughly wash the affected area with lots of soap and water. Dry the area and check for residue. If there are still lingering chemicals, rewash the hands but with less water to allow a more concentrated soap mixture to remove oils.

  • For direct eye contact- If possible, immediately use the nearest eye-wash station. Otherwise, irrigate the eyes thoroughly and continuously for at least 15 minutes. Contact the nearest emergency room for further guidance.
  • If consumed- Immediately induce vomiting and seek professional medical attention. It is always best to visit the hospital and receive official clearance to ensure you are not poisoned or facing a life-threatening illness.

And remember, after using WD40 on plastic, make sure you clean the surface thoroughly with a good degreaser like common dish soap. Scrub the surface well, and you will likely not have to worry about an issue down the road.

Is WD40 Flammable?

WD40 contains petroleum distillates which are highly flammable. However, once sprayed and dried, the surface is no longer susceptible to heat, thus eliminating the possibility of a fire. In fact, without a direct heat source, WD40 is merely combustible, meaning it requires a much higher temperature and is reasonably safe to use in small quantities.

How Long Does WD40 Last? Does It Expire?

WD40 has virtually no shelf life. On the can, there is a visible expiration date to indicate the best used by the timeframe. However, WD40’s potency and overall effects do not decrease over time. If stored properly, meaning away from direct heat and at room temperature, a can of WD40 will last forever.

Common Uses of WD40

WD-40 Spraying on Car Paint

WD40 is a multi-purpose product mainly designed to be applied on metal surfaces to protect from both corrosion and unwanted rust. Additionally, WD40 is used to lubricate objects which are stiff and/or jammed.

As a multi-purpose product, WD40 can be used for a wide array of different situations. These applications may include, but are not limited to:

Although WD40’s ingredients remain a secret, we can count on its cleaning, moisture displacing, penetrating, lubricating, and protecting properties to help with almost any and all household projects. Not to mention its portability and affordable price are unbeatable.

Final Thoughts

I hope this article has been helpful for your current project. Let me know how it goes in the comments.

Thanks for reading!

For more, check out Is It Safe to Use Wd-40 on Car Paint? | What You Need to Know.