For the avoidance of misunderstanding, the strict statement is that EACH container (bottle, jar, tube, etc.) may only be a maximum of 100ml total capacity - and that is regardless of whether partly full or even empty. The total collection of all containers must be placed in a clear, resealable bag of a maximum total volume of 1 litre (I think I'm right in saying). Not all airports are religious about this but most are - much to my surprise, after passing through security recently our son produced from his hand baggage a nearly full 1 litre bottle of water. At another airport a lady was stripped of her still sealed duty free perfume purchases, in spite of the receipt being there for all to see - she and I discussed which member of staff would get which perfume. Contact lens fluid is sold in bottles which range from 120ml upward. As always, rules are there for abusing in both directions (common sense is not necessarily shown by those whose nation so often claim it) - the Data Protection Act is an example of a law that is used as an obstruction.