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Cluster Offensive Bavaria

Applications of suspended Nano Silver

Case Study

Bavarian Cluster Nanotechnology

Matthias Nüchter 4.11.09

Content of my short lecture

• Bavarian Cluster Nanotechnology• Nano particles in Environment• Nano silver application in thermoplastic materials

Why is this product called „Nano“?What is the information about its availability on the market?What are the regulatory requirements that govern its existence on the market?What kind of safety testing is being performed?What are the expected risks?

Founded in January 2007 in an initiative of the Bavarian State Founded in January 2007 in an initiative of the Bavarian State Government as part of Bavarian Cluster OffensiveGovernment as part of Bavarian Cluster Offensive

Around 350 partners in Germany, especially in Bavaria, and in Around 350 partners in Germany, especially in Bavaria, and in some other countries.some other countries.

Main tasks of the clusters NanotechnologyMain tasks of the clusters Nanotechnology

Networking for Industry, Science and EducationNetworking for Industry, Science and Education

Development of a nanotechnology networks between industry and scDevelopment of a nanotechnology networks between industry and scienceience

Promotion of cooperation's between research and developmentPromotion of cooperation's between research and development and users in and users in industryindustry

Inserting of nanotechnology in education and professional trainiInserting of nanotechnology in education and professional trainingng

Offensive discussions of risks and chances of nanotechnologyOffensive discussions of risks and chances of nanotechnology

Nanotechnology presents not only nano particles

Nanotechnology is: - semiconductor technology- optic and laser technology- surfaces preparation methods - thin film technology- technologies for nanoproducts- nanoanalytics….

and also preparation / synthesis of nanomaterials(plates, rods, tubes, crystals,…)

Nanoparticles in Environment

- Nano particles are ubiquitary, well know as ultra fine dust.- The number of nano particles (1-100 nm) in closed rooms differs from 103 up to 106

- Free nano particles are instable with an high tendency to agglomeration.- Formation and agglomeration of nano particles are connected in a cycle process

- In all drinks it is possible to find nano particles: coffee, tea, clear juice, wine …

- It is necessary to difference- natural nano particles from cosmic dust, vulcano eruptions, sea spread, mineral dust, organic particles and …

- anthropogenic produced nano particles (exaust emissions, soot or carbon black from all open flames, emissions for electric motors orelectrical heating …)

This two categories can summarized also as ultra fine particles (dust)

- Synthetic nano particles (gold, silica, alumina, silver, titanium dioxide,organic: proteins, dendrimers, liposome

Nano silver which is here discussed, is in all known applications embedded into thermoplastic material

All following remarks refer an colloidal nano Silver material.

These material is used for preparing of master batches (ca. 6500ppm), which are used for derivatization of different thermoplastics (content around 300 ppm).

These thermoplastic materials can be recycled as it is already done.

Principles

Only through „nano-sizing“ the particles the antimicrobial efficiency can be achieved with very small amounts of

silver

The reactive agent is the silver ion Ag+

Nano particles produce in presence of air and water faster Ag+ than micro particles – surface effect.

The active concentration of Ag+ at a substrate surface is smallerthan 10-4 mol/l

The diffusion of Ag+ from the bonded nano particles to the surface is essential for the activity

Expected benefits for the consumer

• Multi-resistant germs can be confined or eliminated in high risk areas• Humans suffering of house dust mite allergy can expect relief• Humans suffering of neurodermatitis can expect relief too• Protective garments for certain professions can be developed without

poisoning the wearer

• Infectiousness in hospitals (MRSA) can be lowered radically

• Reduction of bacteriological corrosion

• Silver is the antibacterial agent with maximum safety for humans.

Why is this product called „Nano“?

• It is nano-sized in all dimensions, particle diameter of silver is 15-30 nm, determined by TEM Analysis and particle measurement

• Through it‘s nano-size the silver can be incorporated into micro-fibres

• The antimicrobial efficiency of silver correlates with particle diameter, smaller particles are more active and overall content can be lowered.

• The reaction to silver ions is an surface reaction on the particles.

Some correlations

- amount of silver in the geosphere: 0,000012 % or 100 µg/kg- amount of silver by food intake: around 0,1 mg (100 µg) per day and adult- critical value (Germany) in drinking water: 0,05 mg/l (50 µg/l)

- bulk concentrations in plastics in the range of 0,005-0,02 wt.% = 50-200 ppm = 50-200 mg/kg = 5*10-4 - 2*10-3 mol/kgare described as very active in literature

- 10 m2 with an active surface film of 10 µm thickness volume: 100 ml with a concentration of 10-4 mol/l Ag+

1 mg Ag+ on 10 m2

Nano-silver within a PET-Microfiber(250 ppm)

focus ion beam picture (FIB)

Silver colloidapprox: 30 nm

cross section of a micro-fibre

Silver colloid

Nano-silver in PET (5.000 ppm)Transmission electron microscope

(TEM)

Nano silver i n t h e r m o p l a s t i c s i n t h e m a r k e t

fibre area non-fibre area

filament fibres staple fibres water related areas

other areas

fabric ( e.g. sheets, shirts)

filling fibres water storage canisters

cable isolation

knitwear (e.g. socks, shits)

blended fibres shower heads plastic items

carpets tubes kitchen ware

cleaning cloth

technical fibres (e.g. fleece)

technical fibres (e.g. fleece)

What is the information about its availability on the market?

What are the regulatory requirements that govern its existence on the market?

• New announcement are expected for 2012• „Task-force“• N-number (BAUA, Germany)• German “Chemikaliengesetz”• German “Gefahrstoffverordnung”• German “Bundesimissionsschutzgesetz”• Novel-Food-Verordnung

Remark: For more informations come to- Presentation of Dr. R. Brinktrine, University of Leipzig, NanoEurope Symposium, CEO-

Forum, November 25 2009, Rapperswil, CH, „The legal framework for the production and

use of nanomaterials and nanotechnology“

R E A C H B i o c i d a l a c t

What kind of safety testing is being performed?

• Oeko-tex 100 for AgPure™

• Dermatological test for the fibres with 200 ppm Ag

both tests have been passed without any objections, no irritation was found

• Pro-active research projects are realized study to cytotoxicity of AgPure™study to silver leaching from polyester fibres

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sample 1 - 190 ppm sample 2 - 170 ppm sample 3 -195 ppm sample 4 - 150 ppm sample 5 - 180 ppm

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Ag-Release [µg/kg]after eluation in water

bacterial inhibition [%]

Silver Release Study on AgPURE™ Nanosilver functionalised Polyester Microfibers(Source: rent-a-scientist GmbH Regensburg, Germany)

Silver leaching from 5 fiber samples with silver content in the range of 150 -195 mg/kg. Fiber samples (1 g) were eluated for 3 h in water (30 ml, pH 4).

Studies of cytotoxicity of AgPure™

All Ding' sind Gift und nichts ohn' Gift; allein die Dosis macht, das ein Ding kein Gift ist.Theophrastus Bombast von Hohenheim, genannt ParacelsusSeptem Defensiones, Basel 1589

- Concentrations of 2,5 mg/ml (2,5 g /l ) and more of free water suspended AgPure™

are toxic against fibroblastic cells L929

- Smaller Concentration are non-toxic.

- In comparison:

Highest concentration of AgPure™ embedded in thermoplastic materials is 200 mg/kg

Highest leached amount of silver is 200 µg in 30 l Water (7 µg/l)

Source: rent-a-scientist GmbH Regensburg, Germany

What are the expected risks?

Using of colloidal silver in medicine is well known since many years and used as in different applications no hazard, near zero

⇑

Risk = Exposure * Hazard

⇓No disposal of silver nanoparticleswas observed in many measurements no exposure, near zero

None of the expected risk seem to prove true

• Nano silver in the here used application form is a suspension in water, no dust is arising

• Production of master batches and thermoplastic derivatisation are done in a closed systems.

no nano silver is released.

• Nano silver is embedded after processing into thermoplastic material no abrasion of nano material is observed (UBA study)

Four Questions which answers by itself

• How much of the released silver will be in colloidal state? In summarization of all known scientific analyses regarding chemistry, medicine and microbiology there is no indication of free nanosilver particles.

Actually our partners are working on the development of analytical methods to differentiate between elemental and ionic silver at very low level concentrations (BMBF, NanoNature, project: “UMSICHT”)

• How much of the colloidal silver coming out of the fibre will actually be in touch with the skin? The here discussed nanosilver material is fused inside the fibre, not being added through some kind of finishing onto the surface of the fibre/fabric.

• How much of the colloidal silver, which really hits the skin, will creep through it or will be brushed/washed away somehow ?

• How much of the colloidal silver which really hits the skin and really got trough it will not be absorbed by the liver and discarded through the kidneys.

What is the involvement of stakeholders and citizens‘groups?

• Discussion with stakeholders on nanotechnology is starting with the founding of Bavarian cluster Nanotechnology.

• Offensive discussion to chances and risks of nano materials is one point of our business and realized permanently by Bavarian cluster nanotechnology.

• Using of different nano materials in consumer products also nanosilver is an important point in our school program.

• Project of recycling of nano silver containing materials is organised at the time.

• The discussion of chances and risks of nanotechnology is a permanent fight against smattering and technophobia.

For more information to Bavarian cluster Nanotechnologyand some of our partners :

www.nanoinitiative-bayern.de

Thank you for your attention !

µg/l0,43maximum loading of wastewater treatment plants

t Ag/a1,97

g Ag/year1.965.600,00

g Ag/kg laundry0,00015Release in waste water

[4]ng Ag / g fibre150,00elution

kg/year*inhabitant13.104.000.000,00

kg/a156,00

[3]kg/week3,00laundry/inhabitant

m3 in DE4.599.000.000,00water using

[2]in DE84.000.000,00inhabitants

m3/a54,75

[1]m3/d0,15water using / inhabitant

Estimation of maximum loading of waste water treatment plants in Germany with silver, if all in Germany washed clothes are equipped with antimicrobialnano silver

Solubility Product Constants of different silver salts

silver chloride AgCl 1,77 x 10-10

silver phosphate Ag3PO4 8,88 x 10-17

silver sulfide Ag2S 1 x 10-29

Table: Silver market 2004/2005

(in tons) 2004 2005Mine production 19.297 19.956in:Peru 3.061 3.191Mexico 2.569 2.871Australia 2.221 2.407China 1.966 2.012Russia 1.166 1.313

recycling 5.636 5.825stock reduction - -goverment sales 2.068 2.115hedging activities 311 469Sum 27.312 28.365Quelle: Gold Fields Mineral Services Ltd. World Silver Survey (2006)

Wastes of Nano Silver Materials

• Thermoplastic material can be recycled.

• Multiple processing of nano silver (yellow) results in the agglomeration of nano particles to micro particles (grey). Micro particles of silver have low biological activity and low discolouring effect.

• The silver concentration in the end-product fibre is so small that you must eat more than 35 g/day to still not get any symptoms of the silver.

This paper was produced for a meeting organized by Health & Consumers DG and represents the views of its author on thesubject. These views have not been adopted or in any way approved by the Commission and should not be relied upon as a statement of the Commission's or Health & Consumers DG's views. The European Commission does not guarantee the accuracy of the dataincluded in this paper, nor does it accept responsibility for any use made thereof.