Most diagnoses in the UK are based on the InternationalClassification of Diseases (ICD), published by the World Health Organization, which is up for revision in 2015.
Mr Macniven also said that coding of the causes of death was being updated to take account of changes to the World Health Organisation's internationalclassification of diseases and related health problems.
Right now hospital coders use a standard called the International Statistical Classification of Diseases and Related Health Problems to classify patients and get reimbursed properly for their care.
The International Maritime Organisation (IMO) said it would consider changing the classification of a substance, but added it was "only a facilitator".