Work areas where fine powders are used or fine particles are generated in the process, as is the case in numerous industries – for example, additive manufacturing and post-processing of components, metalworking, surface treatment, pigment production or compounding.
powder-ex is implemented both as regular skin cleansing in the skin protection plan or as an effective aftercare solution (for example in the case of torn gloves).

An underestimated uptake pathway for very small particles is oral uptake through contamination carry-over. Every person touches his or her face about 400-800 times a day, the majority to the eyes, nose and mouth. Of all the particles that land near the oral cavity, about 40% end up in the mouth. This topic has so far been underrepresented in occupational safety and is all the more important when particles are difficult to remove from the skin.

• Study on oral intake in lead workers: Cherrie 2006: https://academic.oup.com/annweh/article/50/7/693/318136
• E.g. see the study of the German federal institute for Risk Assessment Christo 2021: https://www.mdpi.com/2079-4991/11/10/2623
• Study on hand-mouth-contact and contamination carry-over Mueller 2019: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0213677

Small particles below 20 μm cannot be seen with the naked eye. Some of the particles are smaller than a hundredth of a hair and are very difficult to remove from the skin. As a rule of thumb, the smaller the particles and the more hydrophobic, the less effective water and soap are. 

• e.g. Lewinski 2017: https://www.tandfonline.com/doi/abs/10.1080/15459624.2017.1296238

Soap, surfactants and solvents weaken the natural skin barrier and flush sebum out of the skin pores. This makes it both easier for hazardous substances to penetrate the skin and easier for them to penetrate through pores. This ‚wash-in effect‘ has been known since the 1990s. This has already found its way into the BAuA guidelines (TRGS401).

• German Technical rules for hazardous substances / Technische Regeln für Gefahrstoffe 401: § 4.1: (6): https://www.baua.de/DE/Angebote/Rechtstexte-und-Technische-Regeln/Regelwerk/TRGS/TRGS-401.html
• Wash-in-effect: R. P. Moody et al., Journal of Dermatological Science 9,1995, 48-58.
• Current overview: James 2022: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8903816/

For complementary pre-work skin protection, care should be taken not to use creams that compromise the skin barrier. Many prophylactic skin creams contain penetration enhancers. This makes it easier for hazardous substances to penetrate the skin. Even barrier creams without penetration enhancers do not provide perfect protection, as this is reduced over time by perspiration and the wearing of PPE.

• Only skin protection products should be used that have confirmed their effectiveness according to the guideline of the Arbeitsgemeinschaft für Berufs- und Umweltdermatologie (ABD): „Occupational skin products“. Only very few barrier creams comply with the guidelines. Please do not hesitate to contact us if you have any questions. TRGS401, 6.4.4. point 3, https://www.baua.de/DE/Angebote/Rechtstexte-und-Technische-Regeln/Regelwerk/TRGS/pdf/TRGS-401.pdf?__blob=publicationFile 

powder-ex is implemented both as regular skin cleansing in the skin protection plan or – if contamination due to preventive measures only occurs in exceptional cases – as an effective aftercare solution (for example in the case of torn gloves).

As a regular skin cleanser, powder-ex complements soap. While soap is useful after going to the toilet, for example, soap should not be used for skin cleansing in the manufacturing environment. powder-ex is used when leaving the premises where powdered materials are stored or processed – for example, before a meal break.

Small particles that are difficult for the body to break down or eliminate (e.g. many metals, plastics and mineral substances) accumulate in organs and lymph glands. In addition, there is a danger that they will penetrate the blood vessels and cause internal bleeding. In the long term, there is a risk of organ damage, reduced fertility, oxidative stress, inflammation and cancer. This also applies to materials that are not classified as carcinogenic, as a decisive factor for accumulation is the size of the particles themselves.

• Overview of the uptake and hazards of microplastics/nanoplastics by the Royal Society of Chemistry: Abdallah 2022: https://pubs.rsc.org/en/content/articlehtml/2022/em/d1em00301a
• As an example of metal particles (similar powders are used in many industries): GizChem data sheet of the BGRCI/BGHM on additive manufacturing with metal powders: https://www.gischem.de/download/01_604106-00_7_1_3980.PDF

As a medium-term consequence of frequent skin contact with particles, skin irritations, allergies and skin diseases may occur. The danger increases when the skin is frequently washed with soap. The skin barrier is weakened, the skin becomes vulnerable and micro-particles thus find it easier to penetrate the pores.

• See GizChem Datasheet of the German employers‘ liability insurance associations BGRCI/BGHM on additive manufacturing with metal powders: https://www.gischem.de/download/01_604106-00_7_1_3980.PDF

• There are numerous studies on the occurrence of dermatitis, allergies and eczema due to frequent contact with soap in various occupational groups. E.G. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2702.2010.03194.x

Hand washing pastes usually contain abrasive bodies. These damage the skin barrier in addition to the soaps, surfactants and penetration enhancers they contain. In addition, small injuries can occur in the skin. Thus, hazardous substances enter directly into the bloodstream.

Hand brushes should be avoided at all costs when working with very small particles.

• Study by the German Social Accident Insurance DGUV: https://www.dguv.de/medien/ipa/publikationen/ipa-journale/ipa-journale2021/ipa-journal2103/ipa-journal2103_handreiniger.pdf

The size distribution of particles in mineral, metal and plastic powders given by the manufacturer is often misleading for occupational safety. It reflects the volume average of particles. Since small particles have much less volume than larger ones, they play a subordinate role in the calculation. For occupational safety with powders, however, it is precisely these particles that are important.

In addition, fine particles in the nanoscale range are often produced during transport and use due to abrasion.

• Da Kleinst- bzw. Satellitenpartikel unter 20 μm im Verhältnis über ein geringes Volumen verfügen, erscheinen diese unterrepräsentiert, obwohl die reine Menge die Menge an größeren Partikeln weit übersteigen kann. Zur Größenverteilung und Satellitenpartikeln in Pulvern in der additiven Fertigung: (ähnliche Pulver werden in vielen Industriezweigen verwendet) Seyda 2018: https://link.springer.com/chapter/10.1007/978-3-662-58233-6_6
• Auf Anfrage auch eigenes REM-Bildmaterial von DermaPurge zu handelsüblichen PT12, Titan, Chrom, Nickel, Aluminium-Magnesium, Stahl, Kupfer und Späne aus gängigen Fräsen, Sägen und rotierenden Schleifern, die eine ähnliche Größenverteilung wie die Neupulver aufweisen.

Hand protection is an important component of occupational safety with very small particles, but it is not sufficient. Only chemical protective gloves (e.g. nitrile) protect against particles smaller than 20 μm. In gloves worn primarily to protect against mechanical impact, particles pass through the fabric. 

However, the use of chemical protective gloves is not without problems:

1. Chemical protective gloves are thin and often tear when worn too long or when working with metal.
2. Längeres Tragen führt zu erhöhter Schweißbildung, was die Aufnahme von Partikeln stark begünstig und Hautirritationen und Allergien auslösen kann
3. Unvorsichtiges An- und Ausziehen der Handschuhe führt oft zum Hautkontakt mit Partikeln

• Siehe dazu bspw. GizChem Datenblatt der BGRCI/BGHM zu Additiven Fertigung mit Metallpulvern (ähnliche Pulver werden in vielen Industriezweigen verwendet): https://www.gischem.de/download/01_604106-00_7_1_3980.PDF

• Zur Tragedauer/Gefährdung von/durch Handschuhe(n) auch: https://link.springer.com/article/10.1007/s00735-022-1554-3
• Und TRGS401: https://www.baua.de/DE/Angebote/Rechtstexte-und-Technische-Regeln/Regelwerk/TRGS/pdf/TRGS-401.pdf?__blob=publicationFile

Vollschutz ist ein wichtiger Bestandteil im Arbeitsschutz mit Kleinstpartikeln. Zu beachten ist:

1. Studien haben gezeigt, dass an den Übergangsstellen zwischen PSA (Handgelenke, Fußgelenke, Gesicht, Hals, ggf. Bauch) immer noch Kontamination vorhanden ist.
2. Längeres Tragen führt zu erhöhter Schweißbildung, was die Aufnahme von Partikeln begünstig
3. Unvorsichtiges An- und Ablegen des Vollschutz führt oft zum Hautkontakt mit Partikeln
4. Typ 5 Anzüge nach DIN EN ISO 13982-2 dürfen für bis zu 15% der Partikel durchlässig sein.

• Zur Durchlässigkeit von Vollschutz: Jennifer L. A. Keir; et.al., Elevated Exposures to Polycyclic Aromatic Hydrocarbons and Other Organic Mutagens in Ottawa Firefighters Participating in Emergency, On-Shift Fire Suppression. Sci. Technol. 2017, 51, 21.
• DIN/ISO Norm: https://www.din.de/de/mitwirken/normenausschuesse/nps/veroeffentlichungen/wdc-beuth:din21:66396910

Die von der BG vorgegebenen Höchstwerte für Partikelbelastung beziehen sich auf das Einatmen von Partikeln, bzw. die Alveolengängigkeit und spielen für die orale Aufnahme der Partikeln nur eine sekundäre Rolle. Weder für eine Belastung mit Nanopartikel in der Luft noch für eine allgemeine Partikelbelastung auf der Haut gibt es aktuell Höchstwerte. Aus diesem Grund und der belegten Gefährdungslage gilt das Vorsichtsprinzip.

• Für Nanopartikel allgemein gilt die TRGS 527: Derzeit liegen in Deutschland keine stoffspezifischen Arbeitsplatzgrenzwerte für Stoffe in Nanoform vor.
• Partikelbelastung in der Luft wird mit Volumen pro Kubikmeter angegeben und ist nicht aussagekräftig, wenn Partikel kleiner als 20 μm sind.
• Unter TRGS 401 (Haut) und TRGS 900 (Grenzwerte) sind keine Grenzwerte für Partikelbelastung auf der Haut angegeben.