Proposed Registration Decision PRD2021-08, Oriental Mustard Seed Meal and MustGrow Crop Biofumigant

Pest Management Regulatory Agency
10 November 2021
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2021-8E-PDF (PDF version)

Summary

This page is a summary of the consultation document. If you would like to comment, please request the full consultation document.

To obtain a full copy of Proposed Registration Decision PRD2021-08, Oriental Mustard Seed Meal and MustGrow Crop Biofumigant please contact our publications office.

Should you require further information please contact the Pest Management Information Service.

Table of Contents

• Proposed registration decision for oriental mustard seed meal
• What does Health Canada consider when making a registration decision?
• What is Oriental Mustard Seed Meal?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Next steps
• Other information

Proposed registration decision for oriental mustard seed meal

Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the Pest Control Products Act, is proposing registration for the sale and use of MPT Mustard Seed Meal Technical and MustGrow Crop Biofumigant, containing the technical grade active ingredient oriental mustard seed meal, to suppress soil-borne Pythium spp., soil-borne Fusarium spp., verticillium wilt, and root knot nematodes on cannabis and industrial hemp grown outdoors, in greenhouses, indoors or in high tunnels.

Oriental Mustard Seed Meal is currently registered to suppress certain nematodes and soil-borne fungi on various field crops and outdoor ornamentals. For details, see Proposed Registration Decision PRD2011-23, Oriental Mustard Seed Meal, and Registration Decision RD2012-03, Oriental Mustard Seed Meal.

An evaluation of available scientific information found that, under the approved conditions of use, the health and environmental risks and the value of the pest control products are acceptable.

This summary describes the key points of the evaluation, while the Science Evaluation of Proposed Registration Decision PRD2021-08, Oriental Mustard Seed Meal and MustGrow Crop Biofumigant provides detailed technical information on the human health, environmental and value assessments of oriental mustard seed meal and MustGrow Crop Biofumigant.

What does Health Canada consider when making a registration decision?

The key objective of the Pest Control Products Act is to prevent unacceptable risks to people and the environment from the use of pest control products. Health or environmental risk is considered acceptable^{Footnote 1} if there is reasonable certainty that no harm to human health, future generations or the environment will result from use or exposure to the product under its proposed conditions of registration. The Act also requires that products have value^{Footnote 2} when used according to the label directions. Conditions of registration may include special precautionary measures on the product label to further reduce risk.

To reach its decisions, the PMRA applies modern, rigorous risk-assessment methods and policies. These methods consider the unique characteristics of sensitive subpopulations in humans (for example, children) as well as organisms in the environment.

These methods and policies also consider the nature of the effects observed and the uncertainties when predicting the impact of pesticides. For more information please refer to the following:

• Protecting Your Health and the Environment
• Pesticide Registration Process
• Pesticide Risk Reduction Program.

Before making a final registration decision on oriental mustard seed meal and MustGrow Crop Biofumigant, Health Canada's PMRA will consider any comments received from the public in response to PRD2021-08.^{Footnote 3} Health Canada will then publish a Registration Decision^{Footnote 4} on oriental mustard seed meal and MustGrow Crop Biofumigant, which will include the decision, the reasons for it, a summary of comments received on the proposed registration decision and Health Canada's response to these comments.

For more details on the information presented in this summary, please refer to the Science Evaluation of PRD2021-08.

What is Oriental Mustard Seed Meal?

Oriental mustard seed meal is the remainder of the seed tissue of oriental mustard seed (Brassica juncea) extracted for mustard oil. Oriental mustard seed meal contains high levels of glucosinolates, which hydrolyze into isothiocyanates. Oriental mustard seed meal is the active ingredient in the end-use product, MustGrow Crop Biofumigant, which is registered to suppress certain nematodes and soil-borne fungi on various field crops and outdoor ornamentals.

Health considerations

Can approved uses of Oriental Mustard Seed Meal affect human health?

Oriental Mustard Seed Meal is unlikely to affect human health when it is used according to label directions.

Potential exposure to oriental mustard seed meal may occur when handling and applying the product. Postapplication exposure to the pesticidal active component, allyl isothiocyanate (AITC), is possible while the treated soil is being watered and before it degrades or volatilizes from the soil. When assessing health risks, two key factors are considered: the levels where no health effects occur and the levels to which people may be exposed. The levels used to assess risks are established to protect the most sensitive human population (for example, children and nursing mothers). As such, sex and gender are taken into account in the risk assessment. Only uses for which the exposure is well below levels that cause no effects in animal testing are considered acceptable for registration.

Toxicology studies in laboratory animals describe potential health effects from varying levels of exposure to a chemical and identify the dose where no effects are observed.

MPT Mustard Seed Meal Technical, containing oriental mustard seed meal, is considered to be of low acute toxicity by the oral and dermal routes, mildly irritating to the eyes and slightly irritating to the skin. It is a potential respiratory irritant and a skin sensitizer. Mustard is also considered to be a priority allergen by Health Canada.

Publicly available literature indicates that the degradation product, AITC, is highly acutely toxic by the oral, dermal and inhalation routes. It is considered to be a severe eye and skin irritant, and some studies have shown skin sensitization potential.

MustGrow Crop Biofumigant is considered to be toxicologically equivalent to MPT Mustard Seed Meal Technical and is considered to be of low acute toxicity by the oral and dermal routes, mildly irritating to the eyes and slightly irritating to the skin. It is a potential respiratory irritant and a skin sensitizer.

Residues in water and food

Dietary risks from food and water are acceptable.

Mustard is used for culinary purposes worldwide. MustGrow Crop Biofumigant is not applied directly to crops, and both oriental mustard seed meal and AITC are expected to rapidly degrade in the soil environment. Consumer exposure to oriental mustard seed meal and AITC is not expected based on the proposed use pattern. In addition, the likelihood of oriental mustard seed meal and AITC residues in drinking water will be low. Consequently, health risks are acceptable for all segments of the population, including infants, children, adults and seniors.

Risks in residential and other non-occupational environments

Estimated risk for residential and other non-occupational exposure is acceptable.

MustGrow Crop Biofumigant is registered for use on food crops and proposed for use on cannabis and industrial hemp (for cannabinoid/cannabidiol (CBD) extraction), grown outdoors, in greenhouses, indoors or in high tunnels. The product label will include measures to reduce bystander exposure such as preventing access to the soil for 24 hours after watering and keeping unprotected persons out of the treated areas for 14 days in order to mitigate risks associated with exposure to the end-use product and AITC. Residential and non-occupational exposure to MustGrow Crop Biofumigant is therefore expected to be low when label directions are observed. Consequently, the risk to residents and the general public is acceptable.

Occupational risks from handling mustgrow crop biofumigant

Occupational risks are acceptable when MustGrow Crop Biofumigant is used according to the label directions, which include protective measures.

Workers handling MustGrow Crop Biofumigant can come into direct contact with oriental mustard seed meal and AITC on the skin or by inhalation. Soil is treated 14 days before planting activities. To protect workers from exposure to MustGrow Crop Biofumigant during loading and application of product to the soil, the label requires workers performing these activities to wear long sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, and NIOSH approved respirator with any N-95 filter or a NIOSH approved powered air-purifying respirator with an HE filter for biological products. Immediately after application, treated soil is watered. If present during watering, the applicator is required to wear long sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, protective eyewear (goggles or face shield) and a full-face respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides, or a NIOSH-approved canister approved for pesticides. There is a restricted-entry interval (REI) of 24 hours after watering and unprotected persons must be kept out of the treated areas for 14 days. Soil intended for cultivation of cannabis and industrial hemp (for cannabinoid/CBD extraction), grown in greenhouses, indoors or in high tunnels, must be treated in an isolated outdoor area and the applicator is required to verbally warn workers of the application and post notification signs around the treatment area to prevent access for 14 days.

The occupational risks are acceptable when the precautionary statements on the label are observed.

Environmental considerations

What happens when Oriental Mustard Seed Meal is introduced into the environment?

When MustGrow Crop Biofumigant, containing oriental mustard seed, is used according to the label, the risks to the environment are acceptable.

Oriental mustard seed meal and the associated secondary compound allyl isothiocyanate are derived from a naturally occurring substance. Oriental mustard seed meal and allyl isothiocyanate are not expected to build-up in the environment, and exposure to non-target organisms is expected to be low. When used as a soil fumigant as per the label directions, the product MustGrow Crop Biofumigant is expected to pose acceptable risks to the environment.

Value considerations

What is the value of MustGrow Crop Biofumigant?

MustGrow Crop Biofumigant suppresses the listed soil-borne pathogens and nematodes on cannabis and industrial hemp grown outdoors, in greenhouses, indoors or in high tunnels.

MustGrow Crop Biofumigant is a biological product that will provide cannabis and hemp growers with an alternative fungicide product to manage certain soil-borne pests and root knot nematodes.

Measures to minimize risk

Labels of registered pesticide products include specific instructions for use. Directions include risk-reduction measures to protect human and environmental health. These directions must be followed by law.

The key risk-reduction measures being proposed on the label of MPT Mustard Seed Meal Technical and MustGrow Crop Biofumigant to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures

Human health

The signal words "CAUTION - EYE IRRITANT", "POTENTIAL SKIN SENSITIZER" and "WARNING: Contains the allergen mustard" are required on the principal display panels of the labels for MPT Mustard Seed Meal Technical and MustGrow Crop Biofumigant. Standard hazard and precautionary statements are also required on the technical grade active ingredient label and the end-use product label to inform workers of the potential for eye, skin and respiratory irritation, and skin sensitization of the product.

Workers handling and applying MustGrow Crop Biofumigant, will be required to wear standard personal protective equipment (PPE) including long-sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, protective eyewear (goggles or face shield) and a NIOSH approved respirator with any N-95 filter or a NIOSH approved powered air-purifying respirator with an HE filter for biological products. If present during watering, the applicator is required to wear a long-sleeved shirt, long pants, chemical-resistant gloves, shoes and socks, protective eyewear (goggles or face shield) and a full-face respirator with a NIOSH-approved organic-vapour-removing cartridge with a prefilter approved for pesticides, or a NIOSH-approved canister approved for pesticides. There is a restricted-entry interval of 24 hours after applying water to the treated soil.

Soil intended for cannabis and industrial hemp (for cannabinoid/CBD extraction), grown in greenhouses, indoors or in high tunnels, must be treated in an isolated outdoor area. The applicator is required to verbally warn workers of the application and post notification signs around the treatment area to prevent access for 14 days.

Unprotected persons must be kept out of the treated areas for 14 days after watering for all uses.

Environment

A precautionary label statement related to greenhouse effluent is required.

Next steps

Before making a final registration decision on oriental mustard seed meal and MustGrow Crop Biofumigant, Health Canada's PMRA will consider any comments received from the public in response to PRD2021-08. Health Canada will accept written comments on PRD2021-08 up to 45 days from the date of publication of PRD2021-08. Please forward all comments to Publications. Health Canada will then publish a Registration Decision, which will include its decision, the reasons for it, a summary of comments received on the proposed decision and Health Canada's response to these comments.

Other information

When the Health Canada makes its registration decision, it will publish a Registration Decision on oriental mustard seed meal and MustGrow Crop Biofumigant (based on the Science Evaluation of PRD2021-08). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA's Reading Room.