I've often wondered why tomato tins are the only tins which seem to have a white coating inside them. I presume it has something to do with the acidity and it's effect on coming into contact with aluminium. Is this right? If so, is it safe?

the tins of toms i have bought have not yet.. had white plastic coating on the can???
but yes it is to stop the rust from occurring in the can.. totally safe..

I' ve noticed that tins of sweetcorn have white plastic on them too.

If you leave products like tomatoes and pineapple in the tins then the tins react with the acid or other natural chemicals.
I always transfer pineapple to a plastic tub because they started to get what seemed like iron filings growing on them.

yes. HO HO HO..

Maybe because tomatoes can be a bit acidic!

Tomatos are acidic and they would corrode the tin can as they would react with it and it would ruin the tinned tomatoes and make them inedible.

I'm not convinced that it's totally safe to consume food contaminated with a chemical known to be an endocrine disruptor. Neither is the Canadian government (BPA banned) nor the EU (banned for babies).