What types of plastics are not reefsafe?

"TW" wrote in message
...
I was given a 50gal plastic rain barrel made by Lee Valley Tools as a
christmas gift. I am hoping to use it to set up a float valve to store
R/O or mix up SW for water changes. Are there any types of plastics
that are not safe to use for this purpose? This dark green plastic
barrel is brand new and never been used. Has anyone ever had a problem
using a plastic container? Anyone have any ideas? I was planning to
thoroughly rinse it out and then fill it, let it soak for a few days and
then dump the water. If anything were going to leach out of it would
this help to avoid any problems?

Thanks,

Todd

Needs to be food grade to be safe, I think some plastics can leech dioxins