Bioplastic Bags: How long will they take to breakdown/biodegrade in a landfill?

Our bags would break down at the same rate as other organic materials in landfills.

Any claim that defines a specific time frame to biodegrade in landfills is completely misleading. Landfills are not designed to promote the biodegradation of organic waste. Landfills are designed to be stable and entomb the contents. The rate of anaerobic degradation in landfills is dependent on moisture and temperature – where there is little moisture the contents can take generations to biodegrade.