The BBC has posted a very interesting article about when physical contact with work colleagues is appropriate.
This highlights that there's a very definite spectrum of touch - ranging from the friendly squeeze of an arm when someone's unhappy, all the way through to an attempted grope by the watercooler, or worse.
One school of thought says that all touch between colleagues should be avoided. I think that would be very sad indeed.
For example, when I heard that my much-loved old family cat had died, I was at my then-boss's house for dinner with him and his wife and kids. I burst into tears and he promptly gave me a great big hug. That comfort was just what I needed at the time.
And another male colleague always says hello and goodbye to me - and his other lady colleagues - with a peck on each cheek. He's a real English gentleman in other ways too (for example, he stands up when a lady comes into the room), so that touch comes across as courtly and charming - and endearing.
There's a very definite line that shouldn't be crossed. Any overtly sexual touching would feel threatening.
But touch is often a key part of friendship, and why shouldn't colleagues of both sexes become friends?