When we wrote about the LOT-EK building of containers for New York City we received a comment from Marino Kulas of Conforce International, noting that "over 10 million tropical hardwood trees are cut down every year in order to make container floors. These are trees that take 40-60+ years to mature.Having said this, wood is also a less then perfect raw material due to its inherent natural characteristics when it comes to this application." (Conforce makes a wood-free substitute for floors)
My dad was in the container business, and I once asked him if I could have some container flooring material for use as kitchen counters. He laughed and said that container floors are treated with serious insecticides and fungicides to keep alien bugs out of Australia. As container housing becomes such a popular trend, I have wondered if the floors were still treated and asked Marino Kulas, the President of Conforce, if this was still the case; he confirmed that it is. (recent Australian requirements in big PDF here)
According to "Studies on the sorption of organochlorine insecticides by flour stored on or near treated laminated timber or plywood as used in freight containers", Wood preservatives containing a number of organochlorine insecticides, including aldrin, dieldrin, chlordane and lindane, have been approved in Australia for treating timber used as structural components in cargo containers"
All containers are treated for Australian standards because it is impossible to separate them out of the pool for a single country. The study quoted above (of which we can only read the abstract) determined that there was transfer of the insecticides to the products sitting on the floors.
"The highest insecticide residue levels were found in flour samples stored on newly treated laminated sawn timber. Physical pick-up of insecticide from the surface of the floor was considered to be the major source of contamination. Sorption of insecticides from the atmosphere of the container was the most likely source of contamination in samples stored on or near treated plywood."
So for all of those architects working with old shipping containers, check if those floors are toxic. And given the amount of hardwood being chopped to make new containers that are shipped one way from China, perhaps we need a deposit system for these as well so that they go back and get reused instead of stacking up over here. ::Conforce