AHPA Shuns Class 1 Solvents

SILVER SPRING, Md.Class 1 solvents "are not appropriate for use, and should not be used, in the manufacture of herbal extracts," according to the American Herbal Products Association (AHPA), which has amended its existing guidance policy. The amendment, approved by AHPAs board of trustees in July, also amends the policy concerning the use of acetic acid when it is present in liquid extracts formulated to contain vinegar or acetic acid.

Class 1 solvents are not to be used because they are known or suspected carcinogens and environmental hazards, according to the International Conference on Harmonization (ICH). Class 1 include benzene; carbon tetrachloride; 1,2-dichloroethane; 1,1-dichloroethene; and 1,1,1-trichloroethane.

According to ICH, class 2 solvents should be limited because they are non-genotoxic animal carcinogens or possible agents of irreversible neurotoxicity or teratogenicity, and class 3 are OK for use because they have low toxic potential or no adequate toxicological data.

Unlike AHPA's trade recommendations, compliance with AHPA's guidance policies is not a condition of membership. Nevertheless, AHPA encourages its members and non-member companies to adopt each of these policies in the interest of establishing consistent and informed trade practices.  

"The previous AHPA policy did not explicitly exclude class 1 solvents as ICH makes exemptions for their use in drug manufacture when no other solvents can be used," said Steven Dentali, Ph.D., AHPA's chief science officer. "AHPA's Standards Committee, which recommended the new policy to the board, wanted to make it clear that these solvents have no place in the manufacture of herbal extracts due to their unacceptable toxicity or status as an environmental hazard. Most of the solvents listed are not used in the manufacture of herbal extracts; AHPA acted to harmonize with the broadly accepted ICH guidelines."

 Dentali also stated that the AHPA Standards Committee "also recognized that some liquid extracts should have an exemption for acetic acid residues when they are formulated with acetic acid or vinegarwhich contains acetic acidin the same way that the earlier guidance policy exempted residual ethanol when it is used as a component in the manufacture of liquid extracts."