Poss carcinogenic/toxic builders material- monkey mulch? Piglet John?

[Ladycurd]

Okay so this is going to be a very weird request but several years ago my dad was telling me about work he did on our family home in the 70's including use of a material that was now banned as a building material (it wasn't asbestos), it was either a flooring screed type thing or a pipe lagging and I swear he said it was called something like Monkey mulch or mush!? At the time he said we needed to be very careful and never dig up the kitchen floor if possible because he now knew it to be dangerous. Fast forward to now and dad died a couple of years ago but mum has had a serious oil leak meaning the kitchen and living room floor has to be dug up (currently tiled). Mum has no idea about this conversation with Dad and is now in a panic about a possible risk to the builders. I have been googling and googling but can't find anything by that name (if I am even remembering correctly) so wondering if anyone here had any ideas especially fount of all builder knowledge Piglet John. Any ideas?

For industrial smelters, steam pipes, and ships boilers, asbestos used to be used for insulation and pipe lagging. I don't know of another building material he might have meant. You can get tests done on suspect materials. Usually they scrape or break a bit off and send for testing, but you might need someone to drill into the floor.

Ask your local council first.

...if you are in an industrial area (steelmaking, coalmining, gasworks, nuclear power station, oil refinery) where people might have used waste or contaminated material for hardcore, the building control office, or waste disposal depts at the council, or a wrinkly old local builder, will probably know about it. I doubt your old dad was the only person to have used whatever it was. I suppose it might have been vermiculite insulation, but AFAIK it is dusty, but not a dangerous material. Some common waste is damaging to concrete, but not dangerous.

Monkey mulch was a term used for hardcore that may have crushed corrugated asbestos in it