Microbeads in toiletries - Method 623.1

1. Introduction

Plastic microbeads that are less than or equal to 5 millimetres (mm) in size have been determined to be toxic to the environment under the Canadian Environmental Protection Act, 1999 (CEPA). This method covers the analysis of microbeads in toiletries to support the CEPA Microbeads in Toiletries Regulations. The method employs different types of extraction techniques to separate the non-plastic components of the product and by using sieving and/or filtration to isolate the undissolved components. The presence of plastics is confirmed using Fourier-Transform Infrared Radiation (FT-IR).

2. Scope and application

This method is applicable to the identification of plastic microbeads in consumer products, specifically, toiletries.

Samples applicable to this regulation are consumer products and are submitted either in the original product container or as a subsample from a bulk product. The sample matrix will be liquid or solid and have various viscosities and water solubility. The procedures described in this method are applicable to liquids and solids.

Microbeads in products are extracted and analyzed to determine the composition of the beads. FT-IR is used to determine and provides confirmation of the presence or absence of plastic microbeads.

This method is qualitative only. Due to the limitations of the FT-IR, quantification is not possible which requires isolating all plastic materials and weighing these materials.

2.1 Definitions

The below definitions apply to microbead and plastic within this document.

• 2.1.1 Microbead

  • Plastic particles that are less than or equal to 5 mm in size as set out in item 116 of the List of Toxic Substances in Schedule 1 to the Canadian Environmental Protection Act, 1999.

• 2.1.2 Plastic

  • Plastic is considered to be made up of synthetic polymeric substances and capable of being molded into shape while soft and maintaining its rigid or slightly elastic form at temperatures lower than 40°C.

To establish the requirements of the presence of plastic microbeads, the analysis must show that the following criteria are met:

1. There are individual particles as defined in section 2.1.1 and

2. These particles are made of plastic as defined above in section 2.1.2.

The method is fit for its intended use as described in this document along with the method performance data for this method.

3. Interferences

• 3.1 Water insoluble compounds may cause interferences with the FTIR spectrum.

• 3.2 Fine clays, water insoluble oils and fats can clog pores in filter paper or sieves.

4. Sample collection, preservation and handling

• 4.1 Collect in plastic or glass containers, or as supplied by retailer in their original containers.

• 4.2 Do not preserve samples.

• 4.3 Samples can be stored at room temperature. Holding time is indefinite or as indicated by product label.

• 4.4 The minimum quantity required to analyze one sample is 50 grams (g).

5. Reagents and materials

Use reagent grade chemicals unless specified otherwise.

• 5.1 Dawn liquid dishwashing detergent, household.

• 5.2 Reference material of various plastics (that is, Nylon, Poly (methylmethacrylate), Polyethylene, et cetera.)

6. Apparatus

Prepare glassware for this method according to a Standard Operating Procedure (SOP) for glassware cleaning for organic chemical analysis

• 6.1 Balance, Top Loading, readability 0.01 g

• 6.2 Beakers, 150 millilitres (ml) and 1000 ml

• 6.3 Erlenmeyer flask, 125 ml

• 6.4 Glass dish; minimum size 15 centimetres (cm) x 15 cm

• 6.5 FT-IR (Fourier-Transform Infrared Spectroscopy) System, Perkin Elmer

  • 6.5.1 Spotlight 200i (Microscope)

  • 6.5.2 Spectrum Two UATR (Ultra Attenuated Total Reflectance)

  • 6.5.3 Stage Controller – Controller for Spotlight 200i and Spectrum two

  • 6.5.4 Computer with Spectrum Two software.

• 6.6 Sieve Stack

  • 6.6.1 Glass dish; minimum size 15 cm x 15 cm and one litre (L), for collecting filtrate from sieve stack

  • 6.6.2 Sieve, 8 inch diameter, Size: 355, 250, 150, 125, 74, 63, 53, 45, 32 and 20 micrometres (µm).

• 6.7 Spatula

• 6.8 Stir bar, magnetic, glass encased.

• 6.9 Stirrer/hot plate.

• 6.10 Thermometer, infrared.

• 6.11 High Pressure Stainless Steel Filtration Unit.

  • 6.11.1 142 mm, 1L capacity, able to sustain a pressure of 500 kilopascals (kPa) applied to the solution to be filtered.

  • 6.11.2 Reinforced pressure tubing.

  • 6.11.3 Filter paper, ashless, various grade 20-25 µm, 11 µm, 8 µm, 6 µm, 3 µm and < 2 µm pore size, 150 mm (Whatman or equivalent).

  • 6.11.4 Filter paper, cellulose membrane, 0.8 µm. 0.45 µm, 0.2 µm, 0.1 µm pore size, 142 mm (Millipore or equivalent).

• 6.12 Vial, 20 ml.

7. Procedure

• 7.1 Extraction procedures to follow in order to obtain best results.

  Note: Start with extraction as specified in section 7.1.1 and proceed through the extraction procedures successively to isolate particles, if necessary. Any or all of the following extraction procedures can be used in order to extract the particles from the sample matrix as consumer products contain many chemicals that can cause interferences.

  • 7.1.1 Extraction procedure #1: extraction with hot tap water.

  • 7.1.2 Extraction procedure #2: large volume extraction with hot tap water.

  • 7.1.3 Extraction procedure #3: extraction with solution of hot tap water and dawn liquid soap.

• 7.2 Extraction

  • 7.2.1 Extraction procedure #1

    This is the preferred method of extraction and applies to most samples except samples containing immiscible mineral, other oils or organic solvent soluble compounds.

    • 7.2.1.1 Weigh approximately 1-10 g of sample into a 125 ml Erlenmeyer flask. Record the sample weight to 0.01 g accuracy. Add 50 ml hot tap water.

      Note: A larger size Erlenmeyer flask may be used, as needed.

    • 7.2.1.2 Swirl to mix then add a magnetic stir bar and stir at medium speed for 10 minutes.

    • 7.2.1.3 Proceed to Separation (section 7.3) to separate the particles from solution.

  • 7.2.2 Extraction procedure #2

    • 7.2.2.1 Using the quantity of hot tap water specified in 7.2.1.1, the solution could become gelatinous. In that case, quantitatively transfer solution to a 1 L beaker and dilute to ~500 mL with hot tap water.

    • 7.2.2.2 Proceed to Separation (section 7.3) to separate the particles from solution.

  • 7.2.3 Extraction procedure 3

    • 7.2.3.1 Weigh approximately 1-10 g of sample into a 125 ml Erlenmeyer flask. Record the sample weight to 0.01 g accuracy.

    • 7.2.3.2 Prepare a solution consisting of 50 ml liquid dawn detergent and 100 ml hot tap water. Swirl to mix.

      Note: Temperature of hot tap water is around 50°C.

    • 7.2.3.3 Pour the liquid detergent solution into the sample. Add a magnetic stir bar and stir at medium speed for 10 minutes.

    • 7.2.3.4 Apply heat to solution to ensure that the temperature is ≤50 °C. Check temperature using an infrared thermometer.

    • 7.2.3.5 Proceed to Separation (section 7.3) to separate the particles from solution.

• 7.3 Separation

  Note: Follow the steps in this section in successive order.

  • 7.3.1 Decanting

    Note: Certain products may be composed of chemicals that dissolve in water leaving the particles undissolved. If the particles are denser than water and clearly visible, the supernatant can be decanted. Otherwise, proceed to section 7.3.2.

    • 7.3.1.1 Decant the supernatant, retaining the particles at the bottom.

      Note: If heat was applied, allow the solution to come to room temperature before decanting.

    • 7.3.1.2 Rinse the particles with water to remove traces of potential contaminants and air-dry the samples.

    • 7.3.1.3 Use a spatula to transfer the particles to a 20 ml vial.

    • 7.3.1.4 Make a note of the appearance of the particles and presence of other materials. Proceed to section 7.4. Do not proceed further if the sample is positive for plastic microbeads.

  • 7.3.2 Sieving

    Note: Sieving will separate particles of various sizes. Beads larger than 100 µm can be seen as small semi-spherical objects. Beads between 100 and 10 µm will appear as a fine film covering the sieve mesh.

    • 7.3.2.1 Create a sieve stack consisting of the 8-inch sieves listed in section 6.6.

    • 7.3.2.2 Slowly pour the solution through the sieve stack, collecting the filtrate in the glass dish. Due to the tight seal between some of the sieves, the solution may back up at the smaller sieve sizes. If necessary, lightly pull the sieves apart to allow air into the system. Do not discard the filtrate.

      Note: If heat was applied, use heat resistant gloves to pour the solution through the sieve stack slowly.

    • 7.3.2.3 Rinse the stack with tap water.

    • 7.3.2.4 Separate the sieves, rinse each sieve with tap water. If particles are evident on the sieve, tip the sieve at a 45° angle and move the particles to the bottom side of the sieve with tap water. Transfer the particles on each sieve to separate watch glasses and allow to air dry for analysis. Label each watch glass with the pore size of the sieve.

    • 7.3.2.5 If there are sufficient particles, use a spatula to transfer the particles from their respective sieves to separate 20 ml vials. Label the vials with the pore size of the sieve.

    • 7.3.2.6 Make a note of the appearance of particles and presence of other materials. Proceed to section 7.4. Do not proceed further if the sample is positive for plastic microbeads. Otherwise, proceed to section 7.3.3 with the filtrate from the glass dish.

  • 7.3.3 Filtration

    • 7.3.3.1 Assemble the high-pressure stainless steel filtration unit with the largest pore size filter paper (that is, 20-25 µm). Pour the solution from section 7.3.2.6 into the filtration unit. Apply pressure and collect the filtrate into a clean Erlenmeyer flask. Do not discard the filtrate.

      Note: If heat was applied, allow the solution to come to room temperature before filtering.

    • 7.3.3.2 Allow filter paper to dry. Make a note of the appearance of particles and presence of other materials. Use a spatula to transfer the particles from the filter paper to a 20 ml vial. Proceed to section 7.4. Do not proceed further if the sample is positive for plastic microbeads. Otherwise, proceed to section 7.3.3.1 using a smaller pore size filter paper.

      Note: Beads on filter paper can be very hard to see. Gently drag a spatula across the surface of the filter paper to determine if there is any material adhering to the filter paper.

      Note: Filter the filtrate as follows: start with a larger pore size filter paper, continuing to smaller pore size in a stepwise manner ensuring that the 0.1 µm filter paper is the smallest pore size used.

    • 7.3.3.3 Repeat sections 7.3.3.1 and 7.3.3.2 until the sample is positive for plastic microbeads or the smallest pore size filter paper used is 0.1 µm.

    • 7.3.3.4 If particles are not found on the 0.1 µm filter paper or particles are not identified as plastic microbeads, then the result is negative for the sample.

• 7.4 FT-IR analysis

  • 7.4.1 Refer to a standard operating procedure for the operation and use of Perkin Elmer Spectrum Two FT-IR for setup and use of the instrument.

  • 7.4.2 If multiple types of particles are present, analyze each type separately.

  • 7.4.3 Obvious beads or pure material should provide a correlation greater than 0.85. Correlations greater than 0.85 are considered a match and result with a correlation < 0.85 may be considered inconclusive.

  • 7.4.4 Poor resolution of the FT-IR scan due to interferences or mixtures may cause a correlation of < 0.85. Further purification using any or all of the extraction procedures specified in section 7.2 can be used to provide a higher quality match.

  • 7.4.5 Refer to Appendix 1: The List of Common and Other Potential Plastics in Microbeads, however, the two tables in this appendix are not exhaustive.

  • 7.4.6 Refer to Appendix 2: IR Spectra of Common Plastics for comparison of reference material to the spectra of the particle.

  • 7.4.7 If necessary, use the microscope on the FT-IR to confirm the presence of plastic microbeads.

• 7.5 Disposal

  • 7.5.1 For those particles that tested positive for plastic microbeads, dispose through proper hazardous waste disposal. Do not wash the particles down the drain.

8. Calculations and reporting

• 8.1 Using the definition of plastic microbeads in section 2.1, report results as belonging to one of the categories below:

  • 8.1.1 Negative.

  • 8.1.2 Positive. Provide type of plastic.

  • 8.1.3 Inconclusive. Results indicate the presence of a polymer, however, this sample cannot be positively identified as containing plastic microbeads due to the following:

    • 1) instrument limitation

    • 2) matrix interference

    • 3) does not meet the criteria to be both a microbead and a plastic

    • 4) limited quantities of the microbead plastic present in the samples prevent positive identification

9. Quality assurance / Quality control

• 9.1 With each batch of ten or less samples, analyze the following:

  • 9.1.1 One method blank. No detectable plastic microbead must be found in the method blank.

  • 9.1.2 One duplicate sample (if practical). Result for duplicate analysis must match the presence and identification of the plastic microbead.

  • 9.1.3 One reference material. Results for reference material must match the identification of plastic microbead.

• 9.2 Proficiency Testing is to be done at a minimum once per year. Option (vi) of ISO 17025 shall be exercised as per the following statement: “the laboratory may use – but is not limited to – inter-analyst comparisons, analysis of blind reference materials and/or matrix spikes”. If inter-analyst comparison is employed, the result obtained from the inter-analyst comparison must match each other. In the event of the analysis of a blind reference sample, the result obtained must match that of the reference sample obtained previously.

10. Method performance and validation

• 10.1 For up-to-date method validation and uncertainty information, refer to the laboratories protocols.

• 10.2 For up-to-date control charts and trend analysis, refer to individual analytes QC control charts as per the laboratories protocols.

11. Safety and precautions

• 11.1 Wear appropriate personal protective equipment (PPE).

• 11.2 All task hazard analyses (THAs) and save workplace practices (SWPs) pertaining to this method must be reviewed and acknowledged in Q-Pulse before using this method.

• 11.3 Perform this method using safety precautions as per an SOP for general laboratory safety.

12. References

• 12.1 Burke, John; The American Institute for Conservation; Solubility Parameters: Theory and Application; The Book and Paper Group Annual, Volume Three, 1984. Website http://cool.conservation-us.org/coolaic/sg/bpg/annual/v03/bp03-04.html.

• 12.2 Canadian Environmental Protection Act, 1999. S.C. 1999. Website: https://laws-lois.justice.gc.ca/eng/acts/c-15.31/

• 12.3 Environment and Climate Change Canada publication Microbeads – A Science Summary; July 2015. Webpage: http://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=ADDA4C5F-1

• 12.4 Leslie, H.A., PhD; Review of Microplastics in Cosmetics; IVM Institute for Environmental Studies, Report R14/29, July 2014.

• 12.5 Mintenig, S.M.; Int-Veen, I.; Loder, M.G.J.; et al, Identification of Microplastic in Effluents of Waste Water Treatment Plants Using Focal Plane Array-based Micro-Fourier-Transform Infrared Imaging; Water Research, Vol 108, (2017) p 365-372.

• 12.6 NOAA; Laboratory Methods for the Analysis of Microplastics in the Marine Environment: Recommendations for Quantifying Synthetic Particles in Waters and Sediments; NOAA Marine Debris Program; Technical Memorandum NOS-OR&R-48, July 2015.

• 12.7 Proceedings of the GESAMP International Workshop on Microplastic Particles as Vector in Transporting Persistent, Bioaccumulating and Toxic Substances in the Ocean. June 28-30, 2010, GESAMP, UNESCO-IOC, Paris, Pre-Publication copy. GESAMP Reports & Studies No. 82.

• 12.8 Perkin Elmer, Spectrum Two User’s Guide, Part Number L1050228, Release E, November 2012.

• 12.9 Prairie & Northern Laboratory for Environmental Testing, SOP 701.1 Glassware Cleaning for Organic Chemical Analysis.

• 12.10 Prairie & Northern Laboratory for Environmental Testing, SOP 728.1, Operational Notes for Perkin Elmer FT-IR.

• 12.11 Prairie & Northern Laboratory for Environmental Testing, SOP 2002.0, General Laboratory Safety.

• 12.12 Prairie & Northern Laboratory for Environmental Testing, Quality Manual.

13. Deviations from reference method

• 13.1 Minor deviations were made to the spelling and/or grammar of the method to facilitate readability online. These edits do not affect the method procedure or results. To obtain an exact copy of the method contact Produits-Products@ec.gc.ca.

Appendix 1. List of common and other potential plastics in microbeads

Appendix 2: IR spectra of common plastics

Figure 1. Nylon infrared radiation (IR) spectrum

Figure 2. Polycarbonate (PC) IR spectrum

Figure 3. Polyethylene (PE, HDPE) IR spectrum

Figure 4. Poly (methylmethacrylate) (PMMA) IR spectrum

Figure 5. Polypropylene (PP) IR spectrum

Figure 6. Polystyrene (PS) IR spectrum

Figure 7. Polytetrafluoroethylene (Teflon) (PTFE) IR spectrum

Figure 8. Polyvinylchloride (PVC) IR spectrum