Glyphosate is used in New Zealand by farmers, councils and home gardeners. It has recorded more than 40 years of safe use and has been the subject of over 800 studies, all of which have confirmed its safety.
The herbicide offers effective and safe weed control, is low-volatility and degrades quickly in soil. It continues to be rigorously tested by regulators in New Zealand and globally, with over 160 countries approving its safe use.
At the heart of the hype that questions the safety of the herbicide, is a misleading classification by the International Agency for Research on Cancer (IARC) made in 2015. IARC classifies substances using terms such as ‘possibly’ or ‘probably’ carcinogenic to define the potential hazard of a substance. This has led to several everyday products, including coffee, bacon and talcum powder, being categorised as ‘possibly carcinogenic’. But the IARC report is not a risk assessment – it is the type and extent of human exposure that determines the actual risk.
The IARC’s classification is misleading and causes a great deal of unnecessary concern.
Among the four World Health Organization (WHO) agencies that have evaluated the safety of glyphosate, the IARC is the only one to find an association between glyphosate and carcinogenicity. The WHO’s experts from the UN’s Food and Agriculture Organization (FAO) released assessments concluding that glyphosate is ‘unlikely to pose a carcinogenic risk to humans from exposure through the diet’. The WHO’s International Programme on Chemical Safety and Joint FAO/WHO Meeting on Pesticide Residues (JMPR) found that glyphosate is not carcinogenic.
Assessments by the European Food Safety Authority, an independent agency funded by the European Union, also concluded that glyphosate is ‘unlikely to pose a carcinogenic hazard to humans’.
More than four years after reaching its opinion, IARC is an outlier, as leading pesticide regulators around the world continue to conclude that glyphosate is not carcinogenic and that glyphosate-based herbicides are safe when used as directed.
The discrepancy is because the IARC only identifies potential cancer hazards and bases its classification on a small data selection. The joint FAO and WHO assessment uses a much wider data-set to assess the health risks to consumers from dietary exposure to pesticide residues in food.
The World Health Organization said that the ‘IARC reviews published studies to identify potential cancer hazards. It does not estimate the level of risk to the population associated with exposure to the hazard’.
It’s a very important distinction. The IARC report is not a risk assessment. Actual risk is determined by the type and extent of human exposure.
In August 2016, New Zealand’s Environmental Protection Authority (EPA) commissioned a review of the evidence relating to glyphosate and carcinogenicity and concluded that glyphosate is unlikely to be genotoxic or carcinogenic. The regulator deems it safe when used according to label instructions.
Following this, in 2018 the EPA stated that ‘there is no change to the science behind our current position, which is products containing glyphosate remain safe to use when you follow the instructions on the product label’.
As with any chemical product, users of herbicides should consult the product label before use. The label contains safety precautions and guidance.
The Ministry for Primary Industries (MPI) tests residues from commonly used agrichemicals. The food safety regulator confirms that the New Zealand diet is safe and that contaminants are very low – far below levels that would be a food safety risk – and mostly occur naturally. MPI sets very conservative limits for residues in food – many times below levels that would be a risk to consumers.
Conclusions about a matter as important as our health must be non-biased, thorough and based on quality evidence-based science that adheres to internationally recognised standards.
Anyone wishing to know more about glyphosate should review the conclusions reached by regulatory authorities in developed countries that rigorously consider all available data, published and unpublished, in a comprehensive evaluation.
Crop protection products are among the most highly regulated in the world. Regulatory and scientific authorities worldwide have concluded that glyphosate, when used according to label directions, does not pose an unreasonable risk to human health and the environment.