The most common and most likely answer to this crossword clue is the 3 plus 4 letter word ANT BEAR
I've seen this crossword clue in The Times
A
N
T
B
E
A
R
Buddy explains!
The straight part
We know that "sort presenting a threat to workers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sort presenting a threat to workers = ant bear.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.