If you want the full protocol you will need to go to British Standards Institute web site. You have to purchase it.
Basically, here the different test a helmet must go under
1) impact testing under specified velocity. differnt sports standards have differning impact velocityies. for example a motocycle helmet has a differnt test velocity than say kayaking. All impacts must measure under 250 g's for 30 milliseconds. this is the limit. for US bike and other helmet standards the limit is 300 g's. I don't recall the test velocity for 1385 off the top of my head.
the helmets are droped with a head form in them. inside the headform is an acclerometer to meausre the g forces or the peak acceleration when the helmet hits an anvil (there are different shaped anvils too to mimik for exmaple a curb or a smooth rock or a edge of a rock or metal etc.)
helmet samples are impacted above a drawn test line with reference to the headform size that sample is fitted to. helmet samples are also impacted in different areas as well.
2) retention system test: dynamic test to see if the buckles break or the straps break when a load is applied. if straps break or buckles break you fail.
3) roll off test: load up the edge of the helmet with a weight. the weight is drop to see how far the helmet moves. if it move mroe than 30mm you fail.
4) tesing impacts under varying environmental condistions: for example after being submersed in water for 24 hours. after being exposed to UV light for a period of time etc. ( some sports helmet standards will include other type of environmental conditions; for example in extreme cold for ski/snowboarding helmets)
5) specificed sizing: the helmet are tested to see which headforms they fit.
6) there are specified lableing requirments and tracking requirements
7) there can be no uncovered internal protrustion inside the shell. for example rivets must be smashed flat.
oh yeah the helmet has to float for 1385.
hope that helps. if you want more detailed info on the protocol you can search the ASTM site for the standard protocol for testing all types of helmets. or the BSI site. but you will have to pay for the reprints.