ANTIMICROBIAL FABRICS – AN OVERVIEW

Brian McCarthy, Materials KTN and Simon Burnett-Boothroyd, Nylatex Limited

9th November 2009IOM3

DEFINITION

An anti-microbial agent is defined as a natural or synthetic substance which kills or inhibits the growth of micro-organisms such as bacteria,

fungi and algae

Biocidal Products Directive(98/8/EC)

Formally published in Official Journal of the European Communities (Vol 1213) on 24th April 1998

Member States required to implement BPD by 14th May 2000

Final closing date for existing substances 26th September 2002

Main Product Groups:

1 - Disinfectants and general biocidal products (PT1-6)

2 - Preservatives (PT6-13)

3 - Pest control (PT14-19)

4 - Other biocidal products (PT20-23)

Total Product types – 23

Actives authorised at EU level (Final submission date : 1st August 2007)

Products authorised at National Level (At a charge)

EU Definition of a Treated Article / Material

The combination of an article and an active substance, if the active substance is placed on the market as an inseparable ingredient of the article, has to comply with the requirements of the Directive if it is intended that the biocidal active substance is released from the treated article to control harmful organisms outside the treated article (external effect)

or

If it is intended to control only organisms that are not harmful to the treated article itself.

In such cases, the article has the function of a delivery system and shall be considered as a biocidal product that must be authorised.

Decision of EU Competent Authorities July 2005 :

Treated Materials / Articles - Product type 2 (Now?)

BPD Product Type 2 Definition

Product‑type 2:

Private area and public health area disinfectants and other biocidal products.

Products used for the disinfection of air, surfaces, materials, equipment and furniture which are not used for direct food or feed contact in private, public and industrial areas, including hospitals, as well as products used as algicides.

Usage areas include, inter alia, swimming pools, aquariums, bathing and other waters; air‑conditioning systems; walls and floors in health and other institutions; chemical toilets, waste water, hospital waste, soil or other substrates (in playgrounds).

BPD State of Play

Biocidal Products Directive (BPD)Identified Actives: 1,500+

Notified Actives: 800+Dossiers submitted to date: ~1/2 of those anticipated

Therefore likely to be ~400 in total

Low level of awareness / implications within the textile industry

REACHCovers ~30,000 chemicals

Came into Force on 1st June 2007Registration by company so 100,000+ anticipated

Pre-Registration June - December 2008Will cover some aspects of agents authorised under the BPD

Note: Both Directives call for the substitution of the most dangerous chemicals when

suitable alternatives have been identified.

Examples of Treated Articles

Mosquito nets containing insect repellents

Insecticidal strips treated with insecticides

Mattress covers that are labeled as anti mite for use in prevention of the action of house mites outside the cover (i.e. within the mattress)

Impregnated tissues with “antibacterial” properties (if not regarded as medicinal products, e.g. for certain applications in hospitals)

Antibacterial lavatory seats where the active substance is released during use.

Sleeping bag treated with an insect repellent.

Socks treated with a biocidal active substance intended to have a biocidal action on the foot.

Current Efficacy Test Methods

Country / Geography

Test Reference Use Site (optimal matrices)

Test Parameters

Test Organisms Contact Time

Exposure Solution, temperature

USA AATCC Method 174-Part II

Hydrophilic/absorbent textiles, foams

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs “nutrient broth”, saline or other; 37C

  AATCC Method 100 Hydrophilic/absorbent textiles, foams

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs “nutrient broth”, saline or other; 37C

  Draft Method of AATCC (based on NYS-63)

Hydrophobic textiles, plastics

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs “Nutrient Broth”, saline or other; 37C

  ASTM Method E2149-01 (Shake Flask)

All; High volume to sample ratio

K. pneumoniae ATTC 4352 1 and 24hrs

0.3mM phosphate buffer or other; 25C

  ASTM Method E2180-01 (Sloppy Agar)

Hydrophobic textiles, plastics

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs 0.3% agar slurry in saline; 37C

Japan JIS L 1902 - quantitative Hydrophilic/absorbent textiles, foams

K. pneumoniae ATTC 4352 and S. aureus TCC 6538P

18hrs 5% “nutrient broth” in saline; 37C

  JIS Z 2801 Hydrophobic textiles, plastics

E. coli ATTC 8739 and S. aureus ATCC 6538P

24hrs 0.2% “nutrient broth” in distilled H2O; 35C

Switzerland SNV 195124 Most matrices, depends on migration of biocide?

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs??

France XPG-39010 All; targeted for textiles K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

18-24hrs

0.1% Tryptone in saline; 37C

Europe Draft Method of IBRG Plastics Group

Hydrophobic textiles, plastics

E. coli ATCC 10536, P. aeruginosa ATCC 15442 and S. aureus ATCC 6538

24hrs Not finalized; 23C

  “Shake Flask” Method (BISFA) - quantitative

All; High volume to sample ratio

K. pneumoniae ATTC 4352 1, 6 & 24hrs

0.3mM phosphate buffer or other; 25C

 Germany

“Unified Method”; not published but used by Hohenstein Institute

Hydrophilic/absorbent textiles, foams

K. pneumoniae ATTC 4352 and S. aureus ATCC 6538

24hrs 5% “nutrient broth” in saline; 37C

  *** Japan is only current country with performance standards (voluntary)

All these are quantitative methods targeted for bacteria (Gram negative and Gram positive)

** Recommendations for initial bioburden range between 105 and 106 viable cells/ml

Harmonisation of Efficacy Requirements

OECD – Task Force For Biocides

Workshop Recommendations: 1) The working group recommends an acknowledgement that treated materials may be part of an overall hygienic practice rather than substitutes for products that sanitise, disinfect or sterilise

2) The working group recommends that any anti-microbial claims for treated materials MUST be supported by scientifically sound quantitative efficacy data

Future:There will be a 3 tier testing approach Tier 1 : Proof of PrincipleTier 2 : Simulated Laboratory StudiesTier 3 : Field Test Data

Acceptable methodology types for Tier 1 are available (porous & non-porous)

Work is ongoing within OECD to develop a Guidance Note

Additional Needs: Dry methods / Fungal methods / Biofilm challenge / Recovery efficiency AND Resistance development

Points to Note

Efficacy Data MUST support the product claim(s)

Any Data MUST be quantitative

Requirement to show BENEFIT of the treated article

Concern around long term low levels of biocide in the environment giving rise to enhanced development of resistant microorganisms

WITH

Potential for development of cross resistance with antibiotics

SIAA (Japan) have requested assistance from IBRG and are working together to develop JIS 2801 as an ISO standard

Recommendation that all manufacturers of treated articles to get confirmation from their active(s) manufacturers that the active(s) in question are being supported by them through the EU’s authorisation process.

An Industrial View

The top 5 ways that Hospital Infections can be acquired

1. Blood Infections - Highest associated mortality 6%

2. After Surgery 11%

3. Urinary tract infections - Most frequent 23%

4. Chest Infections 23%

5. Skin Infections 10%Report from the committee of public accounts, The management and control of hospital acquired infection in Acute NHS Trust in England (hc306,Session 1999-2000)Paras 1-2; Ev.34

Reducing HAI Infections

• Identify the sources of infection– MRSA carriers on admission to hospital– MRSA infected patients– Environmental

• Break the routes of transmission to other patients– Isolation of carriers/infected patients– Decolonization of MRSA carriers (mupirocinR?)– Hand hygiene compliance is vital (soap vs alcohol)– Environmental cleaning – kill C.difficile spores– Better information for staff/patients/visitors

MRSA carriage transmission

Hospitals

CommunityResidential housesCare homes

MRSA carriers

MRSA carriersMRSA transmission

discharge

PetsPigs?Vets

Patients with infected wounds are an important source of transmission.Important role for medical textiles here.

The Industrial view

Quote!

“Understand your enemy & understand yourself” Sun Tzu

• Raw Material selection (Natural / Synthetic)• Manufacturing process

• Quality Control • Fit for purpose – Robustness & Cost

implications• Legal & Environmental Issues

Material deployment for Infection prevention:

1. Scatter Gun approach – Every Surface and Material in contact within the Healthcare setting.

2. Focused Application (Consider whom is at risk!)• Surgical compliant to the standards (EN13795)• Surgical procedure / Wound management (open and

closed) • Work wear – Uniform & Day wear for employees? (Short

Sleeves) • Patient Application – Modesty gown / Compression

Therapy • Ward surrounding – Curtains / Blinds / Bed linen / Floor’s,

Ceilings? Entrance and Access points ?

Impact on the Healthcare Pathway

New Active Antimicrobials in the European Union

The BPD is an excellent, though costly, and time consuming way of regulating these highly biologically active substances

However Development in the EU of Innovative Novel Actives has now effectively stopped (BUT not in Japan or the USA)

The EU Commission & Member States need to find a way to assist the Development of New Actives with Lower Environmental Impact

Remember

The EU Biocides industry is ~0.1% of the EU chemical industry

BUT

Biocides Protect ~50% of its Production

ANTI-ODOUR CLOTHING

Provides hygiene, freshness and

sense of well-being

Sportswear, socks and footwear

Now standard treatment

Types of Material

CHEMICAL TREATMENTS

e.g. Silver

Antibacterial properties

Or

Natural fibres e.g. Bamboo with inherent antimicrobial properties

ODOUR MANAGEMENT

Effect achieved using anti-microbial-treated textiles – often referred to as bioactive textiles

ANTI-MICROBIALS

Added to textiles to prevent biodeterioration

e.g. staining, odour, discolouration and physical damage

Now added to protect end-users

TRENDS

Surge in demand in recent years

• Rise in participation in outdoor activities• Awareness of the benefits of hygiene

• Prolonging the freshness of cleaned clothes

UK SURVEY

50% of males and 45% of females would pay more for bioactive textiles

Taylor Nelson Sofres - 2007

BAMBOO

Tested in 2003 by the China Textile Industry Testing Centre –

Killed 99.8% of introduced bacteria after 24 hours – much greater than the effect produced by

cotton

CHITOSAN

Applied to sportswear, socks and underwear

APPLICATION

Protect the wearer by:

• Preventing odour production• Limiting skin infections by fungi

• Limiting microbes responsible for disease

APPLICATION

• Into the polymer solution prior to extrusion

• Chemical bonding to the fibre surface

• During textile finishing – non-durable

GROUPS

Organic or inorganic

Bound or unbound

Bactericides or fungicides

Bacteriostats

Organic vs. Inorganic

Organic • Triclosan

• Polyhexamethylene biguanide (PHMB)

Inorganic• Silver, copper, zinc

• oxidants

SILVER

Claims that silver will kill over 650 types of pathogenic organisms

• Anti-odour• Anti-static

• Temperature regulating

• Underwear, sportswear, military textiles, protective clothing, medical textiles

Anti-microbial (bioactive) Textiles

Market

Global – 600,000 tonnes

EU – 150,000 tonnes

(2005)

Major End Use Applications

35% Bedding

30% Medical

25% Hosiery, socks and underwear

10% Sportswear

BIOCIDE PRODUCERS

Aegis

Agion Technologies

Arch Chemicals

Halosource

Microban

Milliken

Sanitized

ANTIMICROBIAL FIBRES

Noble Biomaterials

Amicor

Toray

Trevira

Klopmann

Carrington