These agents may be harmful to humans, animals, and the environment, especially to those who are exposed to the materials for long periods of time. As with tobacco, complex compounds and mixtures can be produced when cannabis is smoked, producing toxic materials. Cannabis smoke will contain pesticide residue if it was also found on the plant itself.

Conventional agricultural commodities are assigned maximum residue levels (MRLs) for pesticides. MRLs are usually established by the government as part of the pesticide registration process, and the same approach may be used for cannabis and cannabinoid products.

Gas chromatography-mass spectrometry (GC-MS/MS) it is not suitable for thermally labile ionic and polar compounds, so is not the best suited for cannabis pesticide testing. Liquid chromatography-tandem mass spectrometry (LC/MS/MS) is the method of choice for cannabis pesticide testing. It is selective, sensitive, can be used with pesticide standards, and works with a wide range of compounds and sample compositions.

Pesticide residue analysis in cannabis is also affected by the differences in pesticide residue and coextracted cannabinoid and terpene concentrations. These materials can affect the MS/MS system, which may then require more instrument downtime and maintenance. This effect can be ameliorated by using a QuEChERS extraction method, diluting the sample, and using internal and matrix-matched calibration standards.