Where the term comes from
The phrase "characterising flavour" appears in the Tobacco and Related Products Regulations, a UK statutory instrument. Its explanatory note says the regulations implement the EU Tobacco Products Directive. The rule itself sits under a heading that reads "No flavoured cigarettes or hand rolling tobacco etc."
The Directive's own prohibition is Article 7(1). A later EU implementing regulation refers to it as the prohibition that must be applied uniformly. This article is based on the excerpts in its research packet, and those excerpts do not reproduce the formal definition of the term. What follows therefore covers how the rule operates, not a word-for-word definition.
An exception for essential additives
The regulations do not ban every additive. They allow an additive that is essential for manufacture, and give sugar as an example, where it replaces sugar lost during curing. Two conditions apply. The additive must not result in a product with a characterising flavour, and it must not increase the toxic effect, addictive effect or CMR properties of the product to a significant or measurable degree.
How a characterising flavour is determined
EU rules set out a common procedure for deciding whether a product has a characterising flavour. A Commission implementing regulation was adopted so that the prohibitions are applied in the same way across the Union. It was made under the Directive's provision on determination procedures.
The procedure can involve an independent advisory panel. Member States may consult the panel and exchange information with each other and with the Commission. Where there is no consensus, the Commission may make the determination itself so that the prohibition is applied uniformly. A Member State that started the process must then align its law and practice with the Commission's decision.
A manufacturer or importer can reply to the process. If it does not dispute that a product has a characterising flavour, or does not reply, the Commission can decide on the information it has. The decision is adopted under Article 7(2) of the Directive.
How the rules applied to menthol cigarettes
Menthol cigarettes were covered by the same flavour prohibition but with a delayed start. ASH, a public health organisation, quotes the UK prohibition as providing that no person may produce or supply cigarettes or hand rolling tobacco with a characterising flavour. It also quotes a transitional provision saying that this rule did not apply to menthol cigarettes until a later date. The primary-source excerpts in this packet do not include that transitional provision, so this account relies on ASH's secondary report of it.
ASH describes the legislation as stemming from the EU Tobacco Products Directive. It says the rules were transposed into UK law and would remain in force after the transition period for leaving the EU. According to ASH, retailer organisations complained about the lack of a sell-through period.
Products outside the rules
ASH also reports that the tobacco industry developed ways around the menthol rules. Its examples were cards that can be inserted into cigarettes or hand rolling tobacco to produce a menthol flavour, and menthol-flavoured cigarillos described as exempt from the regulations. These are ASH's claims about industry activity and are not findings of the regulations themselves.