Fuel bladders or fuel storage bladders are collapsible, flexible storage bladders (also known as tanks) that provide temporary or long term storage for industrial liquids, in this case fuels. These pillow shaped tanks are designed for large volume liquid transport, industrial chemicals, potable water, sludge, and fuel storage. Standard fuel bladder tanks sizes range from 100 US gallons (380 L) to 200,000 US gallons (760,000 L) capacities and larger and custom fuel storage bladders and cells are available, although at sizes exceeding 50,000 US gallons (190,000 L) there is an increased spill risk. To minimize the risk of leakage, and for the sake of containing a catastrophic spill, all fuel bladders should be housed in a secondary containment. The use of fuel bladders without precautionary measures is risky and should not be undertaken. The fines involved with fuel spills are well known and the EPA has set clear guidelines for the use of secondary containment concerning fuel bladders.