Health Canada stands behind the safety of glyphosate

Farmers around the world have been using the herbicide glyphosate for more than 40 years. It is a tool that has helped revolutionize farming by allowing farmers to control weeds without having to till the soil. It has helped with the wide-spread adoption of conservation and no-till agriculture in Canada, which has improved soil health and reduced greenhouse gas emissions from plowing fields.

Is glyphosate safe?

It is among the most thoroughly studied pesticides in the world. In 2017 Health Canada released its re-evaluation decision on glyphosate. A re-evaluation is part of Health Canada’s regular cycle that requires pesticides be re-reviewed every 15 years to ensure they meet the most current scientific standards for health and safety. In its re-evaluation decision, Health Canada confirmed the safety of glyphosate.

This decision was challenged by a number of critics who submitted specific concerns with the findings of the re-evaluation. Health Canada’s Pest Management Regulatory Agency (PMRA) went through each and every notice of objection and ultimately determined that there was no scientific evidence that would warrant changing its decision on glyphosate. Specifically, Health Canada stated that:

“After a thorough scientific review, we have concluded that the concerns raised by the objectors could not be scientifically supported when considering the entire body of relevant data. The objections raised did not create doubt or concern regarding the scientific basis for the 2017 re-evaluation decision for glyphosate. Therefore, the Department’s final decision will stand.”

Health Canada said it ‘left no stone unturned’ in its review of glyphosate. It went so far as to select a group of 20 of its own scientists, who were not involved in the 2017 re-evaluation of glyphosate, to evaluate the objections it received to its re-evaluation decision.

Following is a summary of Health Canada’s findings as they relate to some of the most common questions and concerns about glyphosate.

Does glyphosate cause cancer?

Health Canada confirmed that no pesticide regulatory agency in the world finds glyphosate to be a risk to human health, including the risk of cancer, at levels humans are currently exposed.

The International Agency for Research on Cancer’s (IARC) decision to list glyphosate as a “probable” carcinogen contradicts the comprehensive scientific assessment of expert regulators around the world. Because IARC uses a hazard-based system, even a very low risk can end up being identified as a potential problem. There is a significant difference between something that is carcinogenic and saying that it is probably carcinogenic. Many everyday products, including cell phones, coffee and aloe vera extract are categorized by IARC as possible carcinogens.

Do glyphosate residues on food pose a safety risk?

The Canadian Food Inspection Agency has noted that glyphosate residues on food do not pose a health risk to Canadians. In Canada, maximum residue limits (MRLs) establish the maximum amount of pesticide residues that should be found on a crop if the product is used according to label directions. MRLs are established to facilitate trade and they are not indicators of safety. On rare occasions, glyphosate residues that are above MRLs are detected on crops. There has never been an incident where these residue levels have posed a risk to human health. In most cases, MRLs are set 100 times or more below a level that would pose any safety concern.

What impact does glyphosate have on milkweed and monarch butterfly populations?

Health Canada considers milkweed in a crop field to be a pest that can be treated with herbicides. However, the PMRA establishes buffer zones (the distance between an area treated with pesticides and sensitive habitat) to protect non-target plants on the margins of fields, such as milkweed.

The PMRA has reviewed reports related to the impact of glyphosate on nectar-producing flowers along roadside corridors, which serve as important sources of food for adult monarchs, and determined that there is no evidence to connect glyphosate use, nectar-producing flower vegetation and monarch declines. In fact, according to recent reports, monarch butterfly populations wintering in Mexico are at a 10-year high.

Does glyphosate contaminate water?

According to the PMRA, glyphosate breaks down quickly in the environment and is very unlikely to move downwards into groundwater. The PMRA reviewed a study of groundwater in Europe put forward in a notice of objection and determined that there was no evidence that glyphosate persists in the soil or contaminates groundwater.

The PMRA reviewed water monitoring studies from Canada and the United States and determined that concentrations of glyphosate in surface water are relatively low despite more than two decades of glyphosate use and the concentrations do not pose a risk for drinking water.

Do the ‘Monsanto papers’ discredit the science behind glyphosate?

During its re-evaluation of glyphosate the PMRA reviewed 1,300 scientific studies from multiple registrants, published scientific reports, federal and provincial governments, and other regulatory agencies around the world. With regards to the review articles that have been coined the ‘Monsanto papers’, the PMRA had access to all of the raw data, which it reviewed and analyzed itself. After assessing the entire body of scientific evidence, the PMRA has concluded that glyphosate does not pose an unacceptable health risk.

Since the industry is involved in conducting research on the safety of glyphosate, how reliable is the data?

Any research conducted to support the registration of a pesticide must be conducted according to internationally accepted guidelines. This ensures that the data collected is of a high quality and reliable. The PMRA can at any time review and interpret the raw data from the studies. The raw data, including confidential industry studies, are all publicly available in the PMRA Reading Room for anyone to view.

Does using glyphosate prior to harvest pose a health and safety risk for consumers?

Farmers sometimes use glyphosate as a pre-harvest tool to manage late season weeds that can harm next year’s crop and to help ensure the current crop is uniform and ready to harvest. Glyphosate is registered for pre-harvest application only under very specific conditions. For example, the label specifies under which conditions the product should be applied and clearly states how long the grower must then wait before harvesting the crop. This limits the potential for higher than anticipated pesticide residue on the crop. During its re-evaluation of glyphosate, Health Canada considered all food crops for which glyphosate is registered for pre-harvest application in order to assess the risk of dietary exposure and determined that glyphosate residues on food crops do not pose a health and safety risk.

CropLife Canada works closely with industry partners to encourage farmers to follow label directions to minimize the risk of unintended glyphosate residues on crops. Learn more about the industry’s Keep It Clean initiative.

By Pierre Petelle, president and CEO, CropLife Canada
Published on 27 February 2019