Treatment of Trees with Monosodium Methanearsenate (MSMA) for Bark Beetle Control

The arsenical pesticide GlowonŽ or Monosodium Methanearsenate (MSMA) was used for bark beetle management from the mid-1980s to 2004 in various locations in the Interior of the province.  Since 2005, the product's registration has expired and it is no longer used in British Columbia.


MSMA Policy

The Ministry of Forests and Range has a policy and standard operating procedures for the management of MSMA-treated trees.


Risk Analysis

Recent research and analysis concluded that people are not at risk as a result of MSMA’s former use for bark beetle control. The arsenic associated with past application is largely confined to the treated trees and is not migrating into the surrounding soil or vegetation.

This independent study was led by Dr. Ken Reimer, Director of the Environmental Sciences Group at the Royal Military College of Canada, and Dr. William Cullen, Professor Emeritus in the Chemistry Department at the University of British Columbia.

Both authors are recognized nationally and internationally as experts in arsenic toxicology. Dr. Reimer’s research interests include new ways of conducting ecological and human health risk assessments, contaminant uptake, and the transformation and mobility of arsenic in the food chain. Dr. Cullen has published extensively on the speciation, transformation and metabolism of arsenic in the environment.

Forest Practices Board Complaint Investigation


Maps and Identification

Known MSMA Treated Tree Locations


MSMA Environmental Impacts Documentation