Brown marks on towels - look like scorch marks but not..

[callmemrs]

Dh has recently taken to hanging his towels on the bedroom or bathroom radiator to dry off. The towels are now discoloured in patches and no amount of washing will get rid. They look like scorch marks but I don't see how they could be, because the radiators haven't been burning hot when this has occurred- just comfortably warm. Also the patches aren't right across where the towel has been in contact with the radiator, but scattered across the towels. I wondered whether some sort of fluid leaking from the radiators might have caused it but can't find anything.
Any clues on what this is and how to get rid ?

Is he wiping/washing his bottom properly Mrs?

Yeap-'definitely not skids

Any rusty bits on the radiator? Is the paint intact gloss or something more permeable?

Rust marks from the radiator?

We've had those before and this house is now banned from putting towels directly onto radiators as they never come out.

i had this and it was from a couple of rusty patches on the radiator (which dp insists don't need repainting )

My H gets funny little rust coloured spots on his work shirts and we've never been able to fathom out why as nothing else in the wash ever gets them

I get this on my washing when I use our wooden airer or hang them on something wooden.

That's probably not happening though if it's a radiator. How odd.

rust?
mold?

Rust seems the most likely thing - the radiators are fairly old BUT no obvious rust spots on them so still a bit odd

I've got this on some towels and some of dh,s dark jumpers. I thought it was from the washing machine.......not sure though.