MULCH PROBLEM!!!
So i bought the cheap $1.50 bags of mulch from my local big box store, because a full chip drop was going to be too much by about 3x. I just built some raised garden beds/terracing on a hillside, and wanted to mulch the tops of these gardens (only about 75 sqft in all). I wanted the cheap stuff because i want the wood to decompose and add organjic matter to the soil over the next years, and i don't mind adding a bag or two on top every year.
HOWEVER, as i was reading the bag, it says, "Made with 100% recycled wood" and then in small print near the bottom it says, "This is a recycled product. Despite best efforts, the nature of the processing of this product dictates that it may contain foreign materials including, but not limited to, processed wood and non-wood materials. For this reason, this product is not recommended for use around playgrounds, vegetable gardens, or for other sensitive uses and should be visually checked by the installer for impurities." This scared me, because my plan was using it for vegetable garden.
So i did some more research on the web, and "Recycled wood" is old construction and demolition materials, old pallets, etc. There's no way to know what those pallets were exposed to, or had spilled on them. Old construction and demolition materials could be any number of chemically wood.
I googled the recycled mulch on NCBI, and came across a pubmed study that boiled down to: If 1 in 1000th of the wood used was treated lumber (imagine 1000 2x4s, and 1 of them was treated lumber), the arsenic from that 1 board in the bagged mulch would leach into the soil and create toxic levels of arsenic in the soil. NOT COOL. I'm returning the bags, and i guess i'll get a cyprus blend or pine bark nugget mulch ($$), because there is literally no other type of softwood mulch commercially available it appears. It looks like even the colorful mulches use recycled wood.
I've never even considered that the mulch sold at stores could be laced with chemicals like arsenic or OSB glue - i never thought i needed to worry about MULCH.
All-in-all, getting "junky" wood mulch from chip drop, or a local municipality that does tree trimming is by far the best option. So wild.
Maybe i'm late to the party on this one, but i literally had no idea that this was even potentially an issue.