the Cosmetics Directive. The permitted quantities are: up to 1% in fine fragrances; up to 0.4% in eau de toilette; up to 0.03% in other products. European Union suppliers must inform their customers on request if a product contains more than 0.1% by weight of musk xylene. Safety Musk xylene is an analogue of the explosive trinitrotoluene (TNT), so it is unsurprising that its safety characteristics have been studied in some detail. Indeed, the nitro musks were first discovered in an attempt to produce new high explosives. It has also been used – albeit in very small amounts – in mass-market consumer products for the last hundred years. The discovery of musk xylene residues in the environment prompted new concerns about its possible long-term toxicity, and led to the sharp decline in its use from the mid to late 1980s. The European Chemicals Agency has listed musk xylene as a "substance of very high concern" (SVHC) under the REACH Regulation, judging it to be "very persistent and very bioaccumulative" (vPvB) but not meeting the criteria for human or environmental toxicity to be of concern. Explosive properties Musk xylene is used as an example case in the United Nations Manual of Test Methods and Criteria as a substance which shows some explosive properties but which does not have to be transported as Class 1 dangerous goods under the Model Regulations. It is transported as small flakes in plastic bags (maximum 50 kg net mass), which are themselves within cardboard drums to avoid tearing. This does not count as "confinement" in the meaning of explosives tests: indeed, the special packing is intended to prevent over-confinement during transport. It will explode when detonated under confinement (UN gap test) or when heated under confinement (Koenen test), but does not explode under the BAM fallhammer test (limiting impact energy 25 J) or the BAM friction test (limiting load >360 N). There is no ignition, explosion, self-heating or visible decomposition when musk xylene is heated (without confinement) to 75 °C for 48 hours. Nevertheless, musk xylene is classified in the European Union as an explosive under the Dangerous Substances Directive and as a category 1.1 explosive under the CLP Regulation. The European Union classification reflects the fact that hazardous heating under confinement cannot be excluded in the industrial use of musk xylene, as opposed to its transport, and so it is necessary to warn potential users