I drove charter bus for many years. The type of tie I wore was a safety tie. It was pre-knotted with the tie fastened at the back of your neck by Velcro. The Velcro was hidden under your collar so it looked good. Charter buses have large motors in the rear of the bus. A bay door is opened to access the motor. It is not that uncommon to look at the motor or one of its gauges (sometimes mounted partway back in the motor compartment) while it is running. People have died from getting a regular tie caught in one of the moving parts right in front of them. The idea is the Velcro comes undone before the tie pulls you in. These breakaway or safety ties are used in all sorts of industries where you want to look good and be safe. A plant manager may have to dress up even though he or she might have to be around machines with moving parts. A tie is like a loose piece of clothing that can be pulled, and you with it, into places it should not be.
A Velcro fastening system on a lanyard would be bulky or possibly be too small to be effective. Breakaway buckles and pop barrel buckles are safety buckles or connectors. A common use is to make lanyards into break away lanyards. Most lanyards are made of types of cord like 550 Cord. A paracord lanyard will have a very high tensile strength. If a lanyard cord gets caught in something moving, or you are moving and it gets caught on something that is not, you could be strangled. To prevent this, breakaway buckles for lanyards come undone if the lanyard is pulled too hard. These breakaway lanyard clasps or buckles are small, smooth, inexpensive and effective.
Necklaces are like lanyards only much nicer and prettier. Most have a small clasp strong enough to hold it on and weak enough to break if pulled hard. However, necklaces can be made of much stronger material like string, small rope or paracord. In this case they need to have a breakaway buckle for your safety. You really don't want to get hung up, so to speak.
M. Shane Sullivan, Owner/Manager of Paracordgalaxy.com
(Variations of words used: break away, break-away and pop buckles.)