Its explosive and carcinogenic hazards are recognized to be borderline, and musk xylene is a useful example of the lowest level of such risks which need to be taken into account.

[12] Musk xylene is an analogue of the explosive trinitrotoluene (TNT), so it is unsurprising that its safety characteristics have been studied in some detail.

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.

[13] 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.

[14] It is transported as small flakes in plastic bags (maximum 50 kg net mass), which are themselves within cardboard drums to avoid tearing.

[15][16] This does not count as "confinement" in the meaning of explosives tests: indeed, the special packing is intended to prevent over-confinement during transport.

[24] 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 of the risk.

[26] The European Union Risk Assessment Report makes a number of observations about this study:[27] Musk xylene is not genotoxic.

One route of metabolism is through reduction of one or more nitro groups by the intestinal microflora (gut bacteria) to produce aromatic amines such as p-NH2-musk xylene.

[5] Similar residues were subsequently found in European waters such as the Elbe, Stör and Ruhr rivers in Germany, the German Bight area of the North Sea and sewage treatment plant outlets in Sweden.

The European Union Risk Assessment Report reviewed more than a dozen studies of the toxicity of musk xylene to algae and to aquatic vertebrates and invertebrates, and all found no observed effect concentrations greater than 10 μg/L,[38] the chronic aquatic toxicity threshold in the EU REACH Regulation.

[40] Given that musk xylene has a very high octanol–water partition coefficient (log Kow = 4.9),[1] the higher bioaccumulation factors were considered to be the more significant.