Cardboard and Paper as a source of “Browns” in composting
Paper is almost a prerequisite for modern home composting but not all paper is the same, and some is better recycled than composted. Where paper material is both compostable and recyclable the latter is usually the better environmental option as it reduces the need to fell trees. Making paper from recycled material also requires less energy and uses less water than making it from timber. However, there are times when home composting is the better alternative provided the right bin or technique is used.,-e.g. for paper, such as tissues and shredded paper, which in many areas cannot be recycled or composted via the council kerbside collection. In addition, there will be some waste e.g. where food materials have soaked into cardboard which would contaminate the recyclable waste stream if put into the kerbside collection system e.g. greasy pizza boxes. Concern is often expressed in internet forums that printing inks are toxic and therefore printed paper should not be composted, this may well have been the case in the past, but these are now banned, and modern vegetable inks are safe to compost.
Shredding and home composting confidential paperwork containing financial and personal information provides security, but this is not the primary reason for composting shredded paper. Paper is an excellent source of carbon (cellulose) and a means of absorbing moisture from kitchen and catering waste
If a hot composting batch system is being used, where the objective is to produce compost quickly, the lower the lignin content of the paper the better as the woody lignin is slow to breakdown. In cold composting the actual time taken for the paper to decompose is not so important as the normal processing period is much longer and it does not matter if some recognizable paper is present in the final compost as it can easily be put back into the bin. The technique used to produce the paper will effect and this with other information on composting paper and cardboard is given at composting Compost C: N Ratio - www.carryoncomposting.com