[Brendan (chem2clean)]

Hi, cleaned a house two weeks ago, lady called yesterday saying they had a stain which was not there before I cleaned.the stain was under a child's plastic activity set, now this frame is beige and I did not but it on blocks. Went today and had a look at the stain and its yellow and was not moving. Trying to figure out what could have caused it to go bright yellow on a white wool carpet. Would moisture cause it to go this colour. Don't think the lady taken the p.

[ian harper]

hi

just two things to start

1. you must take photos before and after on every job in every room, any damage or marks pointed out on walk though take photo with customer in room so they know you have it recorded, if you find anything during clean again point it out, this will protect you and stop chances. sometimes stuff happens that customer don't know about by pointing it out before and during the clean you remove yourself from any blame.

2. please post some images so we can see what your talking about

respects ian

[John Kelly]

Does the shape of the stain match the shape of the activity set? If it does then it may be BHT Yellowing. Doesn't usually happen after cleaning but you may have activated something either in the carpet backing or underlay which has caused off gassing and resulting discolouration.

[Brendan (chem2clean)]

John, if it was bht yellowing, is there anything that would remove it. It's not covering the whole base of where the unit lay, just one side

[ian harper]

Just had a read up and it might be photobleaching, I will quote from the manual

"Wool yellowing may be accelerated if the carpet is wet, acidic, has been bleached or contains the salts of certain metals, notably aluminium, tin, or manganese. In case of wool the situation is also complicated by the fact that sunlight may cause bleaching, ie cause the pile to become yellow. This occurs particularly if the light falling on the carpet contains a strong blue component and is low in uv.

When photobleaching occurs, protected portions of the carpet (under furniture or rugs) appear yellow in contrast with bleached areas. when this occurs, the client belives that the carpet has yellowed under the furniture rather than bleached in the middle of the room.

Photoyellowing and photobleaching can occur quickly (in a matter of days)"

Hope this helps? probable not much help for this time but good reference for future. Other causes where fluoresent brightening agents which yellow severely on exposure to strong sunlight. sure you know wool will yellow in presence of strong alkalies.