In my travels through the world of urban gardening and horticulture over many years I have met more self-styled "plastic engineers" than there are in M.I.T. This is quite amazing in that most of them do not appear to know something as simple as the difference between capillary action and osmosis.
They also do not seem to know much about urban soil that is often contaminated with toxic metals such as lead and arsenic.
I was reminded of these experiences when reading this post on the Sunset Magazine blog Fresh Dirt. Evidently the horticultural "plastics engineers" were at work again.
My recent post about the Gardener's Supply Grow Bed raised a few concerns in the comments section and on Facebook. Readers expressed concern about the possible leaching of chemicals into the soil and absorption by the plants.
The Grow Beds are made from 100% recycled Polypropylene, an inert polymer that doesn't "leach" even at very hightemperatures.
Here is a list of reasons why they chose to use 100% recycled Polypropylene. This list comes straight from Maree at Gardener's Supply:
* Before polypropylene was invented, the gaseous waste from oil such as propylene and ethylene were simply burned, because they were useless. Today, these gases are used to produce polypropylene, thus drastically reducing atmospheric pollution. The production process also eliminates the potential polluting of rivers, streams and lakes, due to the use of water in a closed cooling cycle.
* The polypropylene we use is entirely recyclable and meets the manufacturing requirements of the Environment Commission - these stipulate that there is a minimum use of natural resource, reduced emissions a long working life and optimum re-use.