Find approved security products in the same way that you should look for an independently accredited locksmith, the same goes for security products.
Sold Secure for example is a test house dedicated to the testing and approval of security products.
List of Approved Security Products
More information on Sold Secure, and more importantly a list of approved products, can be found at www.soldsecure.com
Other forms of independent approval exist such as LPCB etc and with regards to locks in particular there is also the British Standards Kitemark scheme.