The Ontario Building Code | Threaded Cast Iron Drainage Fittings
7.2.6.3. Threaded Cast Iron drainage Fittings
(1) Threaded cast iron drainage fittings shall conform to ASME B16.12, "Cast Iron Threaded drainage Fittings".
(2) Threaded cast iron drainage fittings shall not be used in a water system.
In Plain Language
This clause requires threaded cast iron drainage fittings to meet the ASME B16.12 standard, and explicitly prohibits using them in a water supply system (they're for drainage only).
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.