November 04, 2019 2 min read

3 Classes of Solvents - Part 1

The solubility of the cannabinoids found in cannabis allow for them to be extracted with various organic solvents to create concentrated cannabis products. The solvents employed in cannabis manufacturing, primarily hydrocarbons and alcohol, extract cannabinoids from cannabis plant material, while removing particulates, waxes, lipids, fats, and other dissolved impurities.

Except for ethanol, the limits on the amount of solvent residue that can be present in manufactured botanical products are established by the International Conference on Harmonization (ICH). The ICH has determined 3 classes for solvents and requires processors to justify the presence of any detected residue in their final products. The 3 ICH classes are;

  • Class 1 - Solvents that are extremely hazardous. Class 1 solvents include known human carcinogens, strongly suspected human carcinogens, and environmental hazards. The ICH recommends that Class 1 solvents are avoided in cannabis production.
  • Class 2 - Solvents with degrees of toxicity that warrant solvent-specific exposure limits. The ICH recommends limiting the use of Class 2 solvents.
  • Class 3 - A broad group of solvents that have a set permissible exposure limit of 50 mg per day. In general, products that are produced with Class 3 solvents must not exceed 0.5 percent solvent residue volume by weight.


In general, samples will fail residual solvent screening if a Class 1, 2, or 3 solvent not listed in the table above is detected above its class limit;

ICH Limits Parts Per Million (PPM)

Net Orders Checkout

Item Price Qty Total
Subtotal $0.00

Shipping Address

Shipping Methods