I found the same article, but wanted your personal advice, as I don't rely much on official papers. :)
It is nothing I have ever worked with.
anyway I'm gonna throw this bottle in the garbages, and seek for food grade DE.
Where can it be found? This is not very common here, or maybe in the fish shops (meaning aquariums sellers)?
If I recall right I believe you are in the UK. If so I don't know where you would find it at. Several sites for buying food grade DE have been posted on here previously. Maybe one of these companies will ship overseas. Or check with the UK Ebay.