The International Systems of Quantities (ISQ) standard was published in 1960 to tame the wide diversity of measurement systems being developed across the world, such as the centimetre-gram-second versus the meter-kilogram-second for example. Such a standard is highly motivated by the potential of ``trivial'' (rather error-prone) mistakes in converting between incompatible units. There have been such accidents in space missions, medical devices, etc. Thus, rendering modelling or simulation experiments unusable or unsafe. We address this problem by providing a \textbf{SAFE}-ISQ VDM-library that is: Simple, Accurate, Fast, and Effective. It extends an ecosystem of other VDM mathematical toolkit extensions, which include a translation and proof environment for VDM in Isabelle at https://github.com/leouk/VDM_Toolkit.