The 21st edition of the UN Model Regulations will feature a new UN number for solid medical waste of category A:


Category A is the most dangerous type of infectious substance.

Further information about the new UN number can be found here:

with background information here:

It is expected that the new UN number and associated provisions will feed down to the regulations for different modes of transport, such as ADR, from 2021.

One of the main advantages of the changes is that larger packages will be authorised for the transport of solid waste of Category A, so long as they meet packing group I performance level.

UN 3549 Medical Waste Category A

Of particular note is that the packages are not required to undergo the current puncture  tests required of packages for Category A material by ADR, although inner packagings containing sharp objects must be rigid and resistant to puncture.

Whilst the UN 3549 entry is only intended for solid wastes, small amounts of liquids may be present, so long as sufficient absorbent or solidifying material is contained in inner or intermediate packagings to absorb or solidify any liquid present.

Currently when a consignor has a large volume of such waste to transport they are required, in liaison with their waste management service provider, to obtain an authorisation from the Department for Transport to use large packages, such as wheeled bins, as these are not authorised for Category A substances under current rules.

The UK, who along with Canada were influential in submitting the changes to the UN Committee of Experts, has submitted a multilateral agreement to the UNECE in order to implement the changes ahead of 2021.

Multilateral Agreement M317 initiated by the UK, was agreed by Sweden on 29th March 2019, which means UN 3549 and the provisions detailed in M317 can now be used in the UK for road transport.

Full details and the accompanying letter can be downloaded here:

Our Dangerous Goods Safety Advisor (DGSA) consultants will be happy to explain the provisions and what you need to do to comply if transporting these wastes.

See our Dangerous Goods Consultancy Services here.