Size and amount of microplastics in toothpastes

Size and amount of microplastics in toothpastes
Plastic particles in toothpaste were ~ 100x smaller than microbeads in facial scrubs
6
Authors: A. Verschoora, J. Herremansa,
W. Peijnenburga, Ruud Petersb
RIVM, National Institute for Public Health and The Environment, Centre for Safety of Products and Substances
b
Rikilt, Wageningen, The Netherlands
a
Published by
National Institute for Public Health
and the Environment
P.O. Box 1 | 3720 BA Bilthoven
www.rivm.nl
Sample
Visual appearance
Control
Classical white,
smooth paste
Transparent blue gel,
no visible speckles
Classical white ,
smooth paste
Transparent green
gel with tiny white
speckles
TP1
TP2
TP3
N×10 MP/g
toothpaste
none
mg MP/ g
toothpaste
-
Fraction
<10 um
-
Median
(measured)
-
none
-
-
-
640
(510-800)
170
(130-230)
18.8
(14.1-25.0)
39.4
(27.8-55.0)
97%
2.3 µm
91%
5.0 µm
In search of a threshold size
The size of microplastics is considered as a potential criterion for restriction and enforcement. In order to set an effective threshold for microplastics in personal care and cosmetic
products (PCCP’s) information of actual particle sizes is essential. Therefore, laboratory
tests were performed on three toothpastes from different brands to investigate the size
and amount of polyethylene speckles. In addition company information and public
literature were collected regarding the size of microplastics in facial scrubs and bath
glitters
Consumption
by higher
organisms
Discharge
to STP
Microplastics
pathway
Consumption
by aquatic
organisms
Discharge to
surface water
Sedimentation
Electron microscopic image of particles in
toothpaste. PE particles have a light color.
(Simplified) pathway of microplastics in the environment
Policy implication
Function of microplastics
Microplastic particles in 2 out of 3 the tested toothpastes are abundant (2-4% on a weight
basis) and much smaller (2-5 µm) than in facial scrubs (median size 200-400 µm, ref. 1)
and glitter bath product (60 µm, ref. 2). From these results we conclude that a threshold
(lower limit) value for microplastics of 1 µm would effectively restrict microplastics in
toothpaste, facial ànd bath glitters. The manufacturers of the toothpastes indicated that
they will phase-out microplastics this year (2014) on a voluntary basis.
Microplastics are increasingly used in personal care and cosmetic products; for example in
rinse-off products such as soap, shower and bath products, facial cleaners and toothpaste. The main reason to add microplastics in these products is their abrasive or polishing effect, and sometimes also shimmering effect. When rinsed into the sewage system,
these particles have shown to pass the sewage treatment plants and enter the surface
water, where they are consumed by aquatic organisms.
Method
References
The toothpastes were suspended in water. Microparticles were isolated by filtration over a
coated microfilter with pores of approximately 1 µm. The particle size distribution of the
microparticles is determined by analysis of the microfilter by scanning electronmicroscopy
(SEM). Microplastics were distinguished from mineral particles (for example SiO2 or TiO2
that are often present in toothpaste) by an energy dispersive x-ray detector (EDX).
Through image analysis, a particle size distribution was made for particles between 1 and
1000 µm. The chemical identity of the polymeric microparticles was determined separately with Fourier-Transform-Infrarood (FT-IR).
Ref 1. Fendall, L.S. and M.A. Sewell, 2009, Contributing to marine pollution by washing your face: Microplastics in facial cleansers. Marine Pollution Bulletin, 58(8): 1225-1228.
Ref 2. Leslie, H., 2012, Microplastic in Noordzee zwevend stof en cosmetica. IVM, Report no. W-12/01, Amsterdam, 19 pag. ( in Dutch)
007514
Microplastics are persistent
The ecological risk assessment of microplastics in the aquatic environment has to deal
with many uncertainties in relation to fate and effects. However, the large-scale presence
and persistence of (micro)plastics are undebated and from a precautionary point of view,
actions to reduce plastic debris and microplastics are taken world-wide.