[jeff1966]

Cleaned a  cream 80/20 cut pile h/s/l carpet this afternoon.Pre sprayed with pure clean then agitated with Orech,started to rinse with hand tool on small landing when I noticed green tram lines appear.Recleaned the area but no joy if anything it looked worse.At this point I was a bit worried & started  to panic,after a bit of a think I noticed one of the door plates were loose & decided to pull the carpet back & have look.When I pulled it back I couldn't believe what a saw the green foam underlay had perished leaving behind a green powder.After showing the customer the problem he asked me carry on cleaning as he was replacing the carpet in the near future & just wanted it clean.In 11 years Iv'e never come across this.Would have taken pics but my phone is in for repair.Anyone else come across this?

[Paul Redden Countryfresh]

not me must be rare
tho 

[John Kelly]

This is a common problem especially on stairs with either green or black powder being pulled through. I think this may get worse in the future looking at some of the low quality underlays on the market fromour friends in the east.

[james roffey]

Seen this a couple of times, always when the carpet is very old and bare.