What do you need to know about liquids when flying? For security reasons there are rules for taking liquids, aerosols and gels on flights into and out of Australia and in fact most countries.
These rules are also relevant to international passengers transiting through Australia and passengers traveling on the domestic leg of an international flight.
The restrictions essentially relate to the quantity of liquids, aerosols and gels passengers may take on board the aircraft as cabin luggage.
There are exemptions for medicines and baby products you may need during the flight.
Specifically, if you are traveling with an infant or toddler, you are permitted to carry a reasonable quantity of liquid, aerosol or gel products required for the flight or for any delays that may occur.
Baby products are deemed to include baby milk, including breast milk, sterilised water, juice, baby food in liquid, gel or paste form, and disposable wipes.
The screening officer has the final say as to what "reasonable quantity" is. Products like milk powder (that are not liquid or gels) can be taken on board.
The above summarises only the current Australian restrictions. However, you also need to consider the requirements of any other country you will be arriving in or departing from both on your outward and return trips.
For example, the current Heathrow Airport (UK) security information for check in states that liquids are to be carried in containers no greater than 100ml.
Essential medicines are permitted in larger quantities above the 100ml limit, subject to authentication. Exceptions to the 100ml rule "may" also be made for those carrying baby food and milk, "but you may be asked to taste the liquid when you go through security".
I have previously been asked to open jars of baby food at Heathrow Airport and taste the contents, and also had bottles of water confiscated where, whilst there was less than 100ml in the bottle, the capacity of the bottle was greater than 250ml.
For the current US restrictions on liquids etc see the Transport Security Association website.