The biggest problem with ammo movement on ships comes from the fact that for a long time there was little understanding of the difference between safe handling alongside an ammunition jetty at an ammo facility, and safe handling onboard ship.
Understandably ammo facilities are much more stringent with the rules. As an Ammo Safety Officer it was my job to point out that those same rules don't actually apply to ships not alongside an ammo jetty. Sea Training came out with an msg that pointed out the same. Much of the overcautiousness was removed. It was done to break the previous assumptions and educate CO's who've through their whole career saw it done a certain way. also force lazy Ammo Safety onboard ship to actually read their own damn documents. Examples of changes:
You can smoke on ship, just not within 3m of the transfer route.
You can wear a hat if you like.
Just have to be HERP safe for the particular ammunition and only if the ammo is exposed outside its packing, not fully shut down electronically.
No phones while transferring but that's not for HERP safety its because that's a general safety policy when moving heavy things.
The new one is no cannabis 24hrs before handling ammo. I always make an announcement the day before to remind folks.
And you can transfer ammo in harbour, its not a big deal for 20mm and below sizes, and certainly not a big deal for pyro though people act like its the end of the world when you propose it. I've just had a truck pull up instead of going all the way to the ammo jetty sometimes (for small orders).
Right now for ammo the biggest concern is JSS. The NEQ for that ship is quite large at full load. Though with the energetic/ignition changes of modern explosives I have questions on the validity of NEQ as it currently exists as a proxy for risk.
@AmmoTech90 probably can speak better on this.