Bottom line is .... if you purchased the charger from a reputable Australian retailer and your charger has Australian electrical safety certification - that's RCM (nee SAA), you should not have any safety issues.
However, if the charger you buy is not tested and certified for safe use in Australia, we would be very reticent about ever using it.
Your charger should have at least RCM (SAA) and usually a combination of CCC, CE, ROHS, GS, CB, PSE, or ETL.
All components of such chargers will be designed and produced in accordance with these standard specifications.
An AC charger meeting these specifications will have multiple protection functions such as over-current protection, over-voltage protection and short-circuit protection.
At HomeKit Australia we follow a simple policy - if it plugs in, it must have RCM (SAA) certification.
If not, we don't sell it.