One time I wondered if motor oil bottles were recyclable. I was surprised how vehement a blogger was that they should never go anywhere but in the trash with the cap sealed tightly:
Considering how toxic just the residue inside a bottle can be, can you imagine what 25,000 barrels a day could do to the Gulf Coast?Taking a risk that I shall henceforth be known as a dasher of hopes, I’m going to have to give you a “no” on this one. Motor oil residue has become one of the biggest contaminants for our plastics markets. The residue seeps into the porous plastic and cannot be removed through the washing process. Of course you should never try to rinse or wash a motor oil bottle yourself since motor oil down the sink or storm drain causes a much larger environmental crisis than a plastic bottle in the trash. The market representatives who take our plastics tell us a motor oil bottle in a pile of plastics could potentially contaminate a whole batch of otherwise-recyclable materials and cause the whole lot to be sent to the landfill. So, when you look at it, recycling a motor oil bottle would be the real dasher of hopes for all the other bottles that really wanted to be recycled.