The volumes would be different on either side of the leak. Usually you standardise leak measurements to STP, and give it in standard cubic centimetres per second, SCC/s, i.e. ‘how much fluid would be escaping if it were in a room at one atmosphere of pressure at 20°C’. Makes it easier to compare.
The SI version would be Pascals per second, which simplifies to… kg / (m * s^3)? Kilogram per meter per second cubed?
But in SI you can easily (and metrically) translate it to volume/s, which would then probably be less cumbersome.
The volumes would be different on either side of the leak. Usually you standardise leak measurements to STP, and give it in standard cubic centimetres per second, SCC/s, i.e. ‘how much fluid would be escaping if it were in a room at one atmosphere of pressure at 20°C’. Makes it easier to compare.
Not volume/s, pressure/s