I bought a brand new John Lewis Eric cot 4 years ago. Like many cots it’s made from MDF which is basically wood powder stuck together with urea-formaldehyde and then coated with paint. I discovered to my horror that over time (4 years) the bonding agent decomposes and the MDF returns to dust.
Hence when my granddaughter of 18 months put her leg on one of the bars it disintegrated leaving jagged shards of sharp paint sticking out. Luckily an adult was in the room when it happened but I would strongly recommend going for wood and not MDF for a child’s cot. Also, if you have an Eric cot or similar check the bars by applying light pressure if it is older than two years.