title: Assessing the biodegradability of microparticles disposed down the drain.
abstract: Microparticles made from naturally occurring materials or biodegradable plastics such as poly(3-hydroxy butyrate)-co-(3-hydroxy valerate), PHBV, are being evaluated as alternatives to microplastics in personal care product applications but limited data is available on their ultimate biodegradability (mineralization) in down the drain environmental compartments. An OECD 301B Ready Biodegradation Test was used to quantify ultimate biodegradability of microparticles made of PHBV foam, jojoba wax, beeswax, rice bran wax, stearyl stearate, blueberry seeds and walnut shells. PHBV polymer was ready biodegradable reaching 65.4 ± 4.1% evolved CO2in 5 d and 90.5 ± 3.1% evolved CO2in 80 d. PHBV foam microparticles (125-500 μm) were mineralized extensively with >66% CO2evolution in 28 d and >82% CO2evolution in 80 d. PHBV foam microparticles were mineralized at a similar rate and extent as microparticles made of jojoba wax, beeswax, rice bran wax, and stearyl stearate which reached 84.8  ± 4.8, 84.9  ± 2.2, 82.7  ± 4.7, and 86.4 ± 3.2% CO2evolution respectively in 80 d. Blueberry seeds and walnut shells mineralized more slowly only reaching 39.3  ± 6.9 and 5.1 ± 2.8% CO2evolution in 80 d respectively.
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA. Electronic address: mcdonough.k@pg.com.
authors.forename: Kathleen
authors.initials: K
authors.lastname: McDonough
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Itrich
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Casteel
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Menzies
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Williams
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Kady
authors.initials: K
authors.lastname: Krivos
authors.affiliation: The Procter and Gamble Company, Mason Business Center, Mason, OH 45040, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Price
mesh_terms: D001673:Biodegradation, Environmental; D029798:Blueberry Plants / Q000737:chemistry; D008962:Models, Theoretical; D010969:Plastics / Q000032:analysis* / Q000737:chemistry; D011091:Polyesters / Q000032:analysis* / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D012722:Sewage / Q000382:microbiology; D013228:Stearates / Q000737:chemistry; D062065:Wastewater / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D014885:Waxes / Q000737:chemistry; D000094122:Polyhydroxybutyrates
chemical_list: D010969:Plastics; D011091:Polyesters; D012722:Sewage; D013228:Stearates; D062065:Wastewater; D014874:Water Pollutants, Chemical; D014885:Waxes; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C530758:stearyl stearate; C034743:jojoba wax
keywords: Biodegradation; Down the drain; Microparticles; Natural materials; PHBV foam