Flammablity 

Cardboard is a very flammable and understandably a worry when being used as furniture, however there is actually a very easy way to greatly reduce the risk of a piece of furniture igniting, this is Envirograph. Our company uses Envirograph, which is fire retardant spray, on all our pieces. The use of fire retardant spray means that if the treated cardboard comes into contact with a flame it will self extinguish and only leave a charred mark. Envirograph is commonly used on cardboard and fabrics to reduce flammability in theatres and commercial events and it is a water-based spray, even though it contains some chemicals. It is an odourless and colourless spray and cardboard becomes considerably less flammable under Envirograph treatment. You can also paint on the treated cardboard or upholster a piece to make the risk of a fire even less likely.