BfR Annual Report 2015

BfR

Annual Report 2015

New techniques for identifying and

characterising microplastics

Be it toothpaste, peeling products or shower gel – the use

of plastics containing products in our daily lives is steadily

increasing. Consequences are the growing accumulation

of so-called microplastics, tiny plastic particles, in aquatic

as well as terrestrial ecosystems. This is not only due to the

decomposition of large plastic products but also due to

the polymer particles that are used in cosmetic products,

for example. There are a number of tasks that need to be

performed in the area of consumer health protection: suit-

able detection methods need to be developed, the entry

pathways into the human food chain must be identified,

and the potential effects on human health must be deter-

mined. Water-repellent particles in particular can prove to

be “Trojan horses”: it is probable that these particles take

up harmful substances from the environment via adsorp-

tion and then gradually release these substances in the

human body.

Together with the Lower Saxony State Office for Consumer

Protection and Food Safety, the BfR is working on new

procedures for the identification and characterisation of

microplastics. Besides Fourier transform infrared spec-

troscopy (FTIR), which identifies polymers based on their

specific vibrations of chemical bonds, the other focal point

of this work is the development of mass spectrometry

analysis methods. Using pyrolysis gas chromatography

coupled to mass spectrometry, microplastic samples are

thermally fragmented and the resulting gases are charac-

terised by means of mass spectrometry, thereby allowing

identification of the respective polymer. Of particular im-

portance in this context is the imaging process of time-of-

flight secondary ion mass spectrometry (ToF-SIMS). This

technology permits analysis of microplastic particles in

the same form as they occur in the environment. For this

purpose, the polymer surface is “bombarded” with an ion

beam in order to separate the secondary ions, and these

ions are then analysed based on their time of flight. This

process permits imaging of the entire ion spectrum and

hence the determination of particle size and composition.

First ToF-SIMS analyses showed that a high percentage of

the larger polyethylene pellets with a diameter of approx.

five millimetres break down into microplastic particles with

diameters of less than ten micrometres after 14 days.

This process was reinforced during the following 14 days:

the share of the smallest microplastic fraction (particles

between one and 1.5 micrometres in size) increased by

50 %, the second smallest fraction (1.5 to 2.5 microme-

tres) showed a remarkable increase of 350 %. It was pos-

sible to clearly distinguish the individual microplastic par-

ticles from the sample background. This was the first time

an imaging mass spectrometry method had been used

to identify and characterise secondary microplastic par-

ticles. The method that was developed for this purpose is

now to be used for the analysis of real samples.

The research results were published in the journal

Science of the Total Environment.

(DOI: 10.1016/j.scitotenv.2016.04.025)

Risk of poisoning from washing detergent

capsules

Household products must be safe if used for their intend-

ed purpose – but also in the event of foreseeable misuse,

when children are playing, for example, and tasting prod-

ucts with their mouth. Poisoning due to cleaning products

and detergents has been a rare occurrence in the past,

but there has been a new trend in recent years that gives

rise to concern from the view of BfR and the European

Commission: many laundry detergents now come in the

form of soft plastic pods filled with coloured fluid that dis-

solve during the washing cycle. These “liquid caps” are

easy to dose – one cap per cycle – and are particularly

popular in France and Italy. There are still very few of

these detergent capsule products marketed in Germany,

and it is unclear whether this situation will change in fu-

ture. As gel capsules appear to be more appealing to

children than traditional detergents, accidents are more

So-called microplastics, tiny plastic particles, are

accumulating more and more in aquatic as well as

terrestrial ecosystems.