I've bought 4 packs of engineered floor boards, made of a multi-ply core.
Today I've received the floorboards, and in one pack, one board had mould on the 'back' side. See picture below (the picture shows the entirely of the area on which mould has grown).
Questions
Is it a good idea for me to install that mouldy board as part of the new floor?
Is it a good idea for me to install the other boards which were in the same pack as the mouldy board? (including the one which was directly in contact with the mouldy area).
What would you do?
More details
That board was in a pack of 6 boards. None of the other 5 boards show any sign of mould.
I've sprayed some white vinegar and sanded the mouldy area. That removed most of the mould, but not all of it.
I want to install the floorboards on a chipboard subfloor, with an 3.5mm underlayment (https://www.amazon.co.uk/gp/product/B00CL9EI0G/) between the subfloor and the floor boards.
We're scheduled to install the new floor in 5 days time.
I'm mildly allergic to mould.