If the silver metalised shielding bags, holding static sensitive components, are to be handled outside of an"EPA", you can choose the metalised shielding bags (a faraday cage).
It can be an effective faraday cage, subject to the quality of material and physical condition. You shouldn't crease the bag, because this can breakdown the integrity of the metallised shield .
Metallised Shielding bags CAN DETERIORATE with use, MONITORING them for effectiveness is VERY IMPORTANT!

BLACK CONDUCTIVE BAGS
It is POSSIBLE TO DAMAGE a static sensitive component inside a Black Conductive bag with a contact ESD!
Black Conductive bags, holding static sensitive components, should only be handled in an EPA and while the person is grounded in order to ensure that no potential difference occurs.
Black Conductive bags allow for a good path to Earth when used with other.