Nanotechnology in Fertilizers and Supplements

Transcription

1 Nanotechnology in Fertilizers and Supplements February 21, 2017 Nathalie Decan, Ph.D. Safety Evaluator, Fertilizer Safety Section Canadian Food Inspection Agency 2007 Her Majesty the Queen in Right of Canada (Canadian Food Inspection Agency), all rights reserved. Use without permission is prohibited.

2 Background/Introduction: Nano? Health Canada considers any manufactured substance or product and any component material, ingredient, device or structure to be nanomaterial (NM) if: (1) It is at or within the nanoscale in at least one external dimension, or has internal or surface structure at the nanoscale (1-100 nanometers inclusive); or (2) It is smaller or larger than the nanoscale in all dimensions and exhibits one or more nanoscale properties/phenomena. 2

3 Background/Introduction: Why NMs? The rapid expansion of NM applications and NM marketplace presence prompts the question Why NMs? 3

4 Background/Introduction: Why NMs? Their nanoscale size imparts: Unique characteristics affecting performance, quality, safety, and/or effectiveness of a product. Chemical, physical and biological properties that differ from those of their macro-scale counterparts. Potential for: altered toxicity and behaviour with a largely unknown impact on human health and the environment. 4

5 Nanotechnology in Fertilizers and Supplements The Fertilizers Act defines: Fertilizer : any substance or mixture of substances, containing nitrogen, phosphorus, potassium or other plant food, manufactured, sold or represented for use as a plant nutrient. Supplement : any substance or mixture of substances, other than a fertilizer, that is manufactured, sold or represented for use in the improvement of physical conditions of soils or to aid plant growth or crop yields. 5

6 Nanotechnology in Fertilizers and Supplements Nano-fertilizers and supplements: Includes products that: (1) consist entirely of NMs (2) contain NMs as a component or (3) otherwise involve the application of nanotechnology. 6

7 Nanotechnology in Fertilizers and Supplements Desirable Properties of nano-enabled fertilizers and supplements: Controlled release formulations Solubility and dispersion for mineral micronutrients Nutrient uptake efficiency Loss rate of fertilizer nutrients Effective duration of fertilizer release Increase resistance to stress and improve crop yield 7

8 Nanotechnology in Fertilizers and Supplements Nanotechnology can enable highly controlled nutrient release: Nutrient can be encapsulated inside a NM (nanotubes or nanoporous materials) The nutrient is coated with a thin, protective polymer (NM) film Nutrients are delivered as particles or emulsions of nanoscale dimension ON-DEMAND nutrient delivery that is synchronized with the nutritional demand of the crop potentially mitigating nutrient leaching and promoting environmental sustainability of fertilizer use. 8

9 Urea: rich source of nitrogen and a commonly used fertilizer. High solubility of urea molecules is reduced by incorporating it into a matrix of hydroxyapetite nanoparticles (similar to naturally occurring rock phosphate). Demonstrate the potential to maintain crop yields while reducing the urea used by slowing nitrogen release. Accepted January 9,

10 Nanotechnology in Fertilizers: Safety? From a safety standpoint, fertilizers and supplements containing NM or featuring nanotech merit special consideration. Importantly, we cannot categorically judge all products containing NM as intrinsically benign or harmful. Assessment of the characteristics of each finished product and safety for its intended use (case by case basis) is the currently accepted way forward. 10

11 NM-Containing Product Regulation in Canada The Pest Control Products Act, the Feeds Act and the Fertilizers Act are CEPA-Equivalent for the purposes of risk assessment of new substances. These establish a legal regime for the assessment and management of new and existing substances (including NMs), and requires importers or manufacturers of new substances to provide specific information to government officials so that it can be evaluated for potential effects on human health and the environment. 11

12 Requirements of the Risk Assessment Process Access to sufficient, good quality, relevant, data Scientific expertise in data interpretation Independence of the assessors and transparency of the process. Clear explanation of the findings along with the rationale and the areas of uncertainty Human Health and Environmental Risk Assessment: (RA) i) range of exposure conditions (during manufacture, use and disposal), to each substance of interest i) identification of hazard properties ii) susceptible population groups and uncertainties in the RA 12

13 Risk Assessment Process: Nanomaterials Does a substance in nano form = a higher risk to human health / environment than the macroscale counterparts? Can hazard data on a substance in other physico-chemical forms be used for NM assessments?? Each substance in a new nano-form needs to be considered individually. 13

14 Special Considerations for Safety Assessment NM Characterization: Given that NMs often exhibit new or altered physicochemical characteristics, it is important that these properties are identified and appropriately addressed during safety evaluations. A wide range of physical and chemical properties should be evaluated during NM characterization including assessment of impurities present. 14

15 Special Considerations for Safety Assessment Examples of toxicity mechanisms: Dissolution: Surface effects: NM structure effects: NM Trojan horse effects: The release of toxic constituents from NMs (e.g., ionic silver from AgNPs etc) Direct effect from physical contact with NMs (e.g., interference with important biomolecules) Inherent properties of the material The capacity of NMs to act as vectors for the transport of substances to sensitive tissues. 15

16 NM Safety Assessment Preparedness The Fertilizer Safety Section is developing a comprehensive risk assessment framework that will enable pre-market safety evaluation of NMs. This approach is being further validated other Government of Canada Departments and is in accordance with OECD recommendations. Diversity of disciplines impacted Terminology Coordination and harmonization across standards developers and stakeholders Rapid speed of development Measurement and characterization Global Impact Materials specifications Health, safety and environment

17 Summary o Fertilizer and supplement manufacturers are beginning to harness nanotechnology to deliberately manipulate or control particle size in order to produce specific, unique technical effects in the final product. o Nano- applications in fertilizers and supplements raises questions about the safety of the products for their intended use. Going forward: We are currently validating of our proposed approach for NM safety assessment. We will continuously access research and safety data as it becomes available, to facilitate ADAPTIVE, case-by-case premarket safety assessment of NMs in fertilizers and supplements. 17

18 Questions? Comments? Nathalie Decan, Ph.D. / Tel.:

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