How to clean CD / DVD that have mold on them

I notice some of my favourite CD and DVD have some mold on them. How do I go about to clean them so that I can still play them?

Solution 1:

DVD and CD are made of Polycarbonate, usually indicated as #7 on resin code (recycling symbol).

According to this answer:

... polycarbonate, which is not very soluble in ethanol or isopropanol, but prolonged exposure may cause crazing or stiffening.

That answer also mentioned that

Most plastics and rubbers are resistant to aqueous solutions and ionic compounds (including most surfactants and soaps)

Soap is not ideal as it is a fat based product, and can leave residue.

Detergent (a type of surfactants) is probably better, but as its chemical compond can vary a lot, it is difficult to say here.

It is safer to use distilled water first, and dry it with microfiber cloth.

There are also cleaning kits available, which I assume includes some kind of safe surfactant spray.

Solution 2:

UPDATED - 11 October 2020

I have found dishwashing liquid is a better cleaning agent with less chemical fumes (compared to mould remover). It's also widely available and cheap.

Step 1.

Identify that the disc has mould growing on the surface (usually the data side). Look closely.

Step 2.

Wash your hands with soap to remove excess hand grease and any particles that may cause scratching.

Step 3.

If you have a few discs to clean (3/4 at a time), arrange them near a sink with some clear bench area. You may want to use an old towel to rest them on. Grab some dishwashing liquid.

Step 4.

Run water slowly over the disc data side up. The water beeds on the disc surface holding it horizontal. Drip one or two drops of dishwashing liquid onto one of the beads of water.

Step 5.

Move the liquid around a little with your finger and then carefully add a small amount of water. Rub the disc gently with your thumb(s) in an outward circular motion for 5 - 15 seconds rotating the disc for even coverage. Do the same for the other side.

Step 6.

Rinse the disc clean holding the disc between thumb and forefinger. Flick the excess water off and check the mould has been removed. If not, repeat the clean. Shake off as much water as possible.

Step 7.

Prepare some pieces of clean paper towel with as little amount of dusty fibres as possible. Arrange 3 drying phases of 2 pieces folded (in sequence) and a drying final resting piece. Push the disc down flat on the first phase with an additional piece of paper towel, move it to the second phase repeat and then the third phase. If the disc still has microdots of water rotate the disc in the air (not rotating while touching the paper towel) and repeat. Then leave on the resting piece. Confirm the mould is gone and the disc is OK.