Zero Rated = Fluorescent

It's very common for fluorescent items to have a specific and unusual function. For instance, emergency vehicles, hi-vis vests, certain chemicals for cleansing or other special purposes, strip lighting used in commercial premises. Medicines are often also coloured in a particular way to ease identification and prevent confusion with foodstuffs. This also includes budgerigars. Jewellery can also be fluorescent in the sense of emitting more visible light than it absorbs, for instance diamonds.

There may well be an unusually wide overlap between fluorescent products and those on which sales tax/GST/VAT is not paid. Hi-vis gear is generally bought for use in workplaces or only worn for paid work; jewellery has as I understand it always been zero-rated; medicines are too; emergency vehicles I'm guessing are also exempt; strip-lighting tends to be used more in places of business; businesses must get through more cleaning products per capita than in the home because of the need for presentation, health and safety regulations and the like.

Moreover, fluorescent products are easier to see than non-fluorescent ones, and therefore easier to detect.

Therefore, the two should be made coextensional. Everything fluorescent should be zero-rated and everything non-fluorescent should have VAT levied on it. This has at least three peculiar consequences: budgerigars become exempt from sales tax, which might encourage budgie-hoarding for money-laundering purposes; all non-luxury food items now have to be fluorescent; any service exempt from sales tax also now has to be somehow fluorescent too in a manner I cannot fully understand. Also, any clothes which have GST levied on them would become exempt from that once washed in non-Brand X detergents, making charity shop clothes much more likely to be exempt.

It might also become possible for a VAT inspector to calculate the VAT on a business premise simply by entering it after dark, illuminating it with a UV light, capturing an image of the "glowing" items and comparing it to an image taken under conventional lighting.