It is far from a vapor barrier - It's not necessarily insulation. Mainly because foil only goods don't have any membrane (compound amongst the layers of reflective materials) transference of heat and or cold can occur. Lots of spray foam insulations are made from petrochemicals and should be a concern https://deancvmdu.ssnblog.com/32579475/jual-plat-besi-grating-an-overview