Not to be partisan, but there are reasons for eco-friendly BBs that break down that have to do with stewardship of the land and land remediation.
Jihad Joe, out in Alberta, owner of Plastic Soldier Airsoft posted the following on the JOCAirsoft website in respect to land remediation:
While oil and petro chemicals are frequently refered to in land remediation, is due to the fact that gas stations and petro chemical stations were being decomitioned with leaky storage tanks.
As the environmental sectors of the gov’t have expanded enforcement to include secondary petro chemical products including STYRENE which is classed as a monocyclic aromatic hydro carbon and is thus classed as a petro chemical.
Now as these regs are new there will most likely be a grandfather clause for exsisting styrene contaminate that can be put in place as aslong as the landowner was diligent in changing to the new regs upon enforcement and that the buyer doesnt object.
here is a nunavut land remediation reg that mentions styrene as a remediatable substance. in this link go to page 30 http://www.gov.nu.ca/env/Contaminate...ion%202010.pdf
here is a link to law times discussing this trend
most provinces are starting to head this way so our styrene bb days are going to end at some point..
SILICA being BIO INERT is not under the class of contaminations...
But this thread was not about eco bbs it was about the silica...
i have hundreds of bags of eco bbs that we can all use anyway..
Styrene BBs will eventually go the way of the do-do bird due to the liability that will exist to remediate lands after use. How and when this occurs will mostly be a political process as the laws are changed to enforce this over time. This is a provincial area of responsibility under Ministries of the Environment and lands management agencies. Each province looks to other provinces for precedents and direction, and the influence is already beginning, as witnessed in those two posted links. I highly recommend the reading if you're a land owner or hoster, its a bit of an eye opener.
See reference below:
... this is an example of some of the information covered in the courses at www.asucanada.com