SI derived unit of dose equivalent (the mean specific energy imparted to an element of matter corrected by a quality factor and a modifying factor to take into account the properties of irradiated matter) equal to one joule per kilogram and admitted for reasons of safeguarding human health.
PAC, 1996, 68, 957 (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 992