AS 1172.4:2019 Sanitary plumbing products
1.5.6  Support and rigidity
The washbasin shall provide for a means of secure support ensuring that when it is installed, no load is placed on the waste pipe or water connections. Support structures, fixings, fasteners, and stiffeners,where provided, shall have a life not less than that of the washbasin.
Washbasins which do not have a separate support structure shall be self-supporting, either from the base or from the flange as appropriate to the type of installation.
1.6  Washbasin strength and support test
With the exception of wall basins (see Clause 1.7), all washbasins when installed in accordance with the manufacturer’s instructions in the designed manner and filled to maximum capacity with water and with a 30 +1/0 kg mass placed or hung on the middle of the front edge of the washbasin, shall, after a period of 2 min, show no sign of fracture, leakage or deformation greater than 5 mm. With the load removed, there shall be no permanent deformation greater than 1 mm and the washbasin shall show no signs of cracks, fracture or leakage.
1.7  Wall basin safety load test
When tested in accordance with Appendix B, wall basins shall show no sign of fracture, leakage or deformation greater than 5 mm. With the load removed, there shall be no permanent deformation greater than 1 mm and the wall basin shall show no signs of cracks, fracture or leakage. Fixings and brackets shall show no signs of failure.
NOTE  Appendix B tests the integrity of the basin, fixed to a rigid wall. It is not the intention to interpret this test as part of installation requirement.
1.8  Overflow prevention test
When tested in accordance with Appendix C, washbasins with an integral overflow, installed with any additional fittings supplied (cosmetic or other) shall prevent water in the bowl flowing over the rim.
The overflow opening shall freely drain to the waste outlet (below plug) or waste pipe system for the washbasin.