| June 2005, Volume 15, Number 1 |
An information service from the Lignin Institute |
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Environmental Protection Agency (EPA) Proposes Expanding List of Approved Lignosulfonates
Following a comprehensive review, EPA has proposed expanding the list of lignosulfonates approved for use as inert ingredients from 7 to 22 (44 exemptions in all). The official proposal (70 Federal Register 7912-7921, 2005) available on line (www.epa.gov/fedregister/.) is valuable as it not only describes the planned regulatory action but also provides a concise summary of the chemistry and safety data available on lignosulfonates. Acute data from animal studies, much of which was supplied by the Lignin Institute’s member companies, along with special studies (sub-acute feeding, dermal, gene mutation etc.) are described. EPA also confirmed that the literature — over 20 websites were searched such as those from the International Program on Chemical Safety, National Toxicology Program TOXNET, and the Agency for Toxic Substances and Disease registry – while not extensive –supports the conclusion lignosulfonates are safe. The FR announcement ascribes a good deal of the safety to their inert nature and not being absorbed by animals or humans.
In proposing the new regulations, EPA is dividing the lignosulfonates into 3 groups.
Group 1 is composed of lignosulfonic acid and the salts produced and used by Institute members. EPA notes that absorption is nil from all routes of exposure based on the physical/chemical properties of the lignosulfonates in this group.
Group 2 contains only 1 compound, Zinc Lignosulfonate. EPA expresses concern for developmental toxicity and immunotoxicity at high doses to perhaps asthma and mutagenicity and thus assigns a “low-moderate” concern for human health concerns while noting that Zn is a required nutrient at low levels in the human diet.
Group 3 is an omnibus collection of lignosulfonates such as reduction and reaction products with formaldehyde and sodium bisulfite; ethoxylated acid, oxidized acid, alkali salt and polymers with formaldehyde and phenol. The agency assigns the same low order of concern as that of Group 1 Lignosulfonates.
EPA also addresses the presence of lignosulfonates in drinking water noting that the salts of Group 1 can be very highly water soluble depending on the cation. The agency also points out that dissolved lignosulfonates may be persistent in ground water.
Producers and users of lignosulfonates will next see these amended regulations published as revised sections to 40 CFR. Section 180.910 – Inert Ingredients Used Pre and Post Harvest: Exemption from the Requirements of a Tolerance”. The published list will include 22 lignosulfonates including the products of interest to LI members. Similarly, these compounds will also be listed in section 180.930 “Inert Ingredients Applied to Animals; Exemptions from the Requirements of a Tolerance”.
This comprehensive regulatory review successfully concludes another su ccessfuproject completed by the Lignin Institute with and for its members.
The Lignin Institute can assist lignin users with information and questions on lignin products. LI is a non-profit organization based in Atlanta, GA. |
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