Just a small tip which may help people to comply with the suggestion to squash bottles in order to save space (WasteServ’s Message in a Bottle TMID, 22 January).

When the plastic bottle is empty pour in some boiling water. Swirl it around the bottle for five or 10 seconds then pour it out. Immediately screw the cap back on and you will find that the plastic will collapse in on itself taking up less space.

Obviously you don’t need to boil water specifically to do this. Keep your plastic bottles until you are running warm water for a bath or to do the dishes.

James A. Tyrrell

N. Ireland