Deuterium and its compounds (including heavy water) in which the ratio of the number of deuterium atoms to normal hydrogen atoms exceeds I : 5 000.
Deoitéiriam agus a chomhdhúile (lena n-áiritear uisce trom) inar mó ná 1:5 000 an coibhneas idir uimhir na n-adamh deoitéiriam agus uimhir na n-adamh normalach hidrigine.