how do i clean the outside of this thing? the white plastic has grey smudges that won't come off.

Diagnosis

The Medify MA-40 V2.0 utilizes a high-impact, matte-finish ABS plastic for its exterior housing. The grey smudges you are seeing are typically not "dirt" in the traditional sense, but rather a combination of "plasticizer migration" and embedded particulate matter. Plasticizer migration occurs when the purifier is placed too close to rubber mats, plastic storage bins, or synthetic fabrics; the chemicals in those materials leach into the porous surface of the MA-40's casing, creating a chemical bond that resists standard dusting. Additionally, because the MA-40 is a medical-grade unit designed to pull high volumes of air, the exterior casing can develop a static charge that attracts fine carbon dust and metallic particles. When these particles are rubbed into the matte texture by a dry cloth, they become embedded in the microscopic "peaks and valleys" of the plastic finish, resulting in grey streaks that appear to be permanent stains. You can confirm this by attempting to wipe a spot with a damp cloth; if the smudge remains unchanged and does not "smear," it is likely a chemical transfer rather than surface grime.

How to Fix It

To remove these smudges without stripping the matte finish or causing "shiny spots" (permanent polishing of the plastic), follow this specific sequence:

1. Dry Dusting: Use a clean, dry microfiber cloth to remove all loose surface debris. Do not use paper towels, as the wood fibers in the paper can create micro-scratches on the ABS plastic.
2. Mild Degreasing: Mix three drops of a mild, clear dish soap (like Dawn) into 16 ounces of lukewarm distilled water. Dip a microfiber cloth into the solution and wring it out until it is barely damp. Wipe the grey smudges using light, circular motions. Avoid scrubbing aggressively, as this can burnish the plastic.
3. Targeted Chemical Removal: For the stubborn grey marks that remain, use 70% Isopropyl Alcohol. Do not spray the alcohol directly onto the MA-40 chassis, as liquid can seep into the control panel buttons or the motor housing. Instead, apply two drops of alcohol to a cotton swab or a clean section of the microfiber cloth.
4. The "Dab and Lift" Technique: Gently dab the smudge with the alcohol-soaked cloth. Let it sit for 5 seconds to break the chemical bond of the plasticizer, then wipe away immediately.
5. Final Rinse: Use a fresh cloth dampened with plain water to remove any residual soap or alcohol, then buff dry with a clean microfiber towel to prevent water spotting.

If That Didn't Work

• Magic Eraser (Melamine Foam): If the smudges are deeply embedded, use a Mr. Clean Magic Eraser. However, be extremely cautious: these are micro-abrasives. Wet the sponge, squeeze out all excess water, and use the lightest pressure possible. If you press too hard, you will remove the matte texture and create a permanent glossy patch on the white plastic.
• White Vinegar Solution: Mix a 1:1 ratio of white distilled vinegar and water. This is particularly effective if the grey marks are actually mineral deposits from hard water or atmospheric pollutants. Apply with a cloth and rinse thoroughly.
• Baking Soda Paste: Create a thick paste using baking soda and a few drops of water. Apply the paste specifically to the smudge and let it sit for 60 seconds. Gently rub in a circular motion with your finger, then wipe clean. This provides a very mild mechanical exfoliation for the plastic surface.
• Plastic Restorer: For severe scuffing that looks like grey scratches, use a dedicated plastic cleaner designed for automotive interiors (non-silicone). Apply a pea-sized amount to a cloth and buff the area to hide the discoloration.

Heads Up

• Avoid Harsh Chemicals: Never use acetone, nail polish remover, or bleach on the MA-40 V2.0. These solvents will melt the ABS plastic or cause the white casing to yellow permanently.
• Control Panel Caution: Keep all liquids away from the top interface buttons. If liquid enters the control board, it can cause the unit to trigger a "Filter Reset" error or cause the fan speed buttons to malfunction.
• Placement Warning: To prevent future grey smudges, ensure the unit is not touching rubberized gym mats or synthetic curtains. Maintain a 2-inch gap between the chassis and any other plastic surfaces.
• Filter Check: If the exterior is getting dirty very quickly, check your HEPA filter. A saturated filter can sometimes allow "blow-back" of particulates that settle on the exterior of the machine.