I hope this is the right group for this question.
On my Apple MagSafe AC adapter, it can take 100 to 240v AC 50/60 cycles. Pretty standard for laptops. Apple's world travel kit includes ends for pretty much every country in the world. But none appear to use grounding/earthing. I have a cord that I use when I'm at home in the US with a three prong NEMA 5-15. On the end that connects to the transformer/brick there are metal contacts that contact the metal button thing on the adapter.
Rather than carry around that cord, I'd rather carry just the adapter and small plug. I know grounding is for "safety." Safety from what? Getting electrocuted? Static? Is there any more inherent danger to using the ungrounded plug?
When I travel outside the US, the cord always comes with me in my checked luggage. So if I run into an alien shaped outlet that doesn't like Apple's design I can use my US grounded cord with a cheap little plug adapter - of which I have plenty.