The smell doesn't just come from rubber, though that is a strong source. It was also in this neoprene floor pad (kind of a kid's play mat) that my mother in law picked up at wal-mart. Whooee boy, there's no way I'd let my kids crawl around on that, or keep it in the house, until it had gassed out in the sun a couple of weeks.
The smell isn't necessarily on every Chinese product, so I don't think it is a pesticide. Also, it is often on products not prone to corrosion, like the floor pad. But it could be that everything out of China is sprayed with some kind of pesticide or preservative, and it is just that the plastics and rubbers absorb more of it for slow-release in the local Harbor Freight.
I think the best theory is that it's part of an unknown recycled mixture. But that particular smell is so distinctive, it has to be something we can identify, dammit! Maybe they add a polymer rejuvenator or something to make whatever junk thrown in the pot mix together with other plastics/rubbers, into a useable material. A general solvent that facilitates the blending of 'close enough' materials.
Serowbot wrote on 05/10/11 at 23:39:17:... and I think I've grown to like it...
I know! Kind of like the smell of gasoline, it has positive associations and grows on you.