Here's my very specific scenario: word-wrap: break word is not working on lists in Safari 10.1 if the first line overflows. Every other line will break properly. The first line will break if with hyphens: auto.
jsfiddle: https://jsfiddle.net/3smrv3tk/
<ol class="test"><li>wrapwraaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaap</li></ol>
screenshot: word-wrap: break-word in Safari 10.1
The worst-case scenario is that I use -webkit-hyphens: auto, but hopefully someone has a more disguised solution!