Pest Management Regulatory Agency
25 May 2012
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2011-14E-PDF (PDF version)
Summary
Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the
Pest Control Products Act and
Regulations, is proposing full registration for the sale and use of Natamycin TGAI and Zivion M containing the technical grade active ingredient natamycin, to suppress dry bubble disease in mushroom production.
An evaluation of available scientific information found that, under the approved conditions of use, the product has value and does not present an unacceptable risk to human health or the environment.
This summary describes the key points of the evaluation, while the Science Evaluation of Proposed Registration Decision PRD2012-14, Natamycin provides detailed technical information on the human health, environmental and value assessments of Natamycin TGAI and Zivion M..
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 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 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 (for example, those most sensitive to environmental contaminants). 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:
Before making a final registration decision on natamycin, the PMRA will consider all comments received from the public in response to Proposed Registration Decision PRD2012-14, Natamycin. The PMRA will then publish a Registration Decision on natamycin, which will include the decision, the reasons for it, a summary of comments received on the proposed final registration decision and the PMRA's response to these comments.
For more details on the information presented in this summary, please refer to the Science Evaluation of this consultation document.
Natamycin is a substance naturally produced by the soil bacterium Streptomyces natalensis that inactivates germinating fungal spores.
Natamycin is unlikely to affect human health when it is used according to label directions.
Exposure to natamycin may occur when handling the end-use product, Zivion M, which is a fungicide to suppress dry bubble disease on button mushrooms (Agaricus bisporus). 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 dose levels used to assess risks are established to protect the most sensitive human population (for example, children and nursing mothers). Only uses for which the exposure is well below levels that cause no effects in animal testing are considered acceptable for registration.
The technical grade active ingredient, natamycin (98%), is of low acute toxicity via the oral, dermal, and inhalation routes. It is severely irritating to the eyes and slightly irritating to the skin. Natamycin is not considered a dermal sensitizer. Cautionary statements indicating the potential for eye irritation are required on the technical grade active ingredient product label.
Dermal exposure is possible for workers handling the end-use product, Zivion M, and for workers engaged in post-application activities such as harvesting, clean-up and maintenance. Therefore, precautionary measures including personal protective equipment (PPE) are required on the end-use product label to mitigate such exposure concerns. The potential for bystander exposure is expected to be minimal as non-workers are not expected to be present in the enclosed mushroom growing houses during the applications.
Dietary risks from food and water are not of concern.
Natamycin has a long history of use as a food additive to prevent spoilage by molds and yeasts, and is approved as a direct food additive in more than 70 countries. The end-use product, Zivion M, will be applied directly to the mushroom bed at casing and at pinning; however, food residue exposure is not expected to be of concern as conservative exposure estimates indicate that the proposed use of Zivion M will not appreciably increase the dietary exposure to natamycin above what is currently expected from its use as a food additive.
Therefore, the proposed use of Zivion M is not expected to result in unacceptable dietary risks when the product is used according to label instructions. In addition, as Zivion M is to be applied inside an enclosed growing house, exposure to natamycin in drinking water is not expected to occur. The PMRA has also determined that a maximum residue limit (MRL) is not required for natamycin.
Occupational risks are not of concern when Zivion M is used according to label directions, which include protective measures.
Occupational exposure to individuals handling Zivion M is not expected to result in unacceptable risk when the proposed product is used according to label directions.
Precautionary and hygiene statements on the label (for example, wearing of PPE) are considered adequate to protect individuals from potential risks from occupational exposure.
The proposed use of natamycin in mushroom houses is not expected to result in environmental exposure.
Natamycin is a naturally occurring substance. When used as proposed in mushroom houses, negligible amounts of natamycin are expected to enter the environment either during use or through the disposal of spent compost medium.
Zivion M is a bio-fungicide that suppresses dry bubble disease in mushroom production.
Zivion M reduces the development of dry bubble disease in commercial mushrooms. It does not affect mycelial growth, and so does not negatively affect mushroom yield.
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 Natamycin TGAI and Zivion M to address the potential risks identified in this assessment are as follows.
The signal words 'DANGER - EYE IRRITANT' are required on the principal display panel of the Natamycin TGAI label. The statements 'Severely irritating to the eye, DO NOT get in eyes are required on the secondary display panel of the Natamycin TGAI label.
The personal protective equipment for all handling, clean-up and maintenance activities required on the Zivion M label includes a long sleeved shirt, long pants, shoes and socks, waterproof gloves, and safety glasses.
No mitigative measures are required for the proposed use of Natamycin TGAI and its end-use product, Zivion M, in mushroom growing facilities.
Before making a final registration decision on natamycin, the PMRA will consider all comments received from the public in response to Proposed Registration Decision PRD2012-14, Natamycin. The PMRA will accept written comments on this proposal up to 45 days from the date of publication of Proposed Registration Decision PRD2012-14, Natamycin. Please forward all comments to Publications. The PMRA will then publish a Registration Decision, which will include its decision, the reasons for it, a summary of comments received on the proposed final decision and the Agency's response to these comments.
When the PMRA makes its registration decision, it will publish a Registration Decision on natamycin (based on the Science Evaluation of Proposed Registration Decision PRD2012-14, Natamycin). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA's Reading Room (located in Ottawa).