Categories of precursor chemicals

The 1988 UN Convention

The 1988 UN Convention lists precursor chemicals in two tables.

Table I

  • Substances which can readily be converted into controlled drugs.
  • Substances which are essential for drug manufacturing.

Table II

  • Other chemicals that are commonly used in drug processing. For example, solvents and reagents.

The European Union regulations

In the EU regulations, the chemicals in the UN Tables I and II are broken down into four categories. It is based on the risk they pose and their level of legitimate use. The difference between the two allows more flexibility in the controls, checks, and monitoring that are applied.

The EU regulations include additional precursor chemicals that are not in the 1988 UN Convention. These have been used in the manufacture of illegal drugs in the EU.

Each category has different requirements under the legislation. Category 1 is the most controlled, while Category 4 is the least controlled.

Category 1

These are substances which can readily be converted into controlled drugs. These have the strictest controls.

  • 1-phenyl-2-propanone (BMK)
  • Diethyl (phenylacetyl) propanedioate (DEPAPD)
  • Alpha-phenylacetoacetonitrile (APAAN)
  • Chloroephedrine
  • Chloropseudoephedrine
  • Ephedrine
  • Ergometrine
  • Ergotamine
  • Isosafrole (cis and trans)
  • Lysergic Acid
  • N-acetylanthranilic Acid
  • Norephedrine
  • Piperonal
  • Pseudoephedrine
  • Safrole
  • Ethyl 3-(2H-1,3-benzodioxol-5-yl)-2-methyloxirane-2-carboxylate (PMK ethyl glycidate)
  • N-phenyl-1-(2-phenylethyl)piperidin-4-amine (ANPP)
  • 1-(2-phenylethyl)piperidin-4-one (NPP)
  • N-phenylpiperidin-4-amine (4-AP)
  • Tert-butyl 4-anilinopiperidine-1-carboxylate (1-boc-4-AP)
  • N-phenyl-N-(piperidin-4-yl) propenamide (norfentanyl)
  • 3,4-methylenedioxyphenylpropan-2-one (PMK)
  • Methyl 3-(1,3-benzodioxol-5-yl)-2- methyloxirane-2-carboxylate (PMK methyl glycidate)
  • 3-(1,3-benzodioxol-5-yl)-2-methyloxirane-2-carboxylic acid (PMK glycidic acid)
  • Alpha-phenylacetoacetamide (APAA)
  • Methyl alpha-phenylacetoacetate (MAPA)
  • Methyl 2-methyl-3-phenyloxirane-2-carboxylate (BMK methyl glycidate)
  • 2‐methyl-3-phenyloxirane-2- carboxylic acid (BMK glycidic acid)
  • Methyl 3-oxo-2-(3,4-methylenedioxyphenyl) butanoate (MAMDPA)
  • Ethyl alpha-phenylacetoacetate (EAPA)

This also includes:

  • The stereoisomeric forms of category 1 substances, not being cathine, whenever the existence of such forms is possible.
  • The salts of category 1 substances, whenever the existence of such salts is possible and not being the salts of cathine.
Category 2

These are substances that are extensively used in the chemicals industry and are essential for drug processing.

Subcategory 2A

  • Acetic Anhydride
  • Red Phosphorous

Subcategory 2B

  • Phenylacetic acid
  • Anthranilic acid
  • Piperidine
  • Potassium permanganate

This also includes:

  • The salts of category 2 substances, whenever the existence of such salts is possible.
Category 3

This includes reagents and solvents which are typically used in drug processing.

  • Hydrochloric acid
  • Sulphuric acid
  • Toluene
  • Ethyl ether
  • Acetone
  • Methylethylketone (MEK)

This also includes:

  • The salts of category 3 substances, whenever the existence of such salts is possible and not being the salts of hydrochloric acid and sulphuric acid.
Category 4

This includes human medicines and veterinary medicines containing:

  • Ephedrine
  • Pseudoephedrine
  • The salts of ephedrine or pseudoephedrine