BTRA

Microbiology Lab Testing

TEXTILE MICROBIOLOGY

The Bombay Textile Research Association [BTRA], a premiere institute for R & D in textiles, started its own Microbiology / Biotechnology division in the year 2003. It caters to routine and specialised work in the field of microbiology not only in the textile field but also in food, water and pharmaceutical fields.

Microbial biotechnology is one of the branches of applied science with diverse applications. The need to safeguard fabrics against microbial attack particularly in industrial usage has long been recognised. Since, each and every entity in this world is prone to attack by microorganisms at some point; textile is no exception to it. Microorganisms are present everywhere in soil, water and air and they need nutrition for the growth. Depending on the substrate available for growth of microorganisms, the durability and aesthetic value of material varies.

The microorganisms play a vital role in deterioration of any material, which is susceptible to attack. The routinely used textile material or which is coming in contact with the body is more prone to attack by microorganisms. This is because during perspiration or when in contact with the body the organisms present on the body gets transferred on to cloth or related material. If such textile material is non-resistant to attack by microorganisms then it can lead to deterioration and hence change in the physical properties. Such material is not only of poor quality but also can cause some skin irritation or allergies.

Hence, it is utmost important to incorporate some form of antimicrobial agent in the textile material to get good quality, longer durability and better aesthetic value. Many textile manufacturers and research laboratories are currently engaged in developing various anti-bacterial and anti-fungal finishes for textile products. The textile finish needs to have properties such as skin friendly and resistant to washings, for its effective usage along with its antibacterial or antifungal effect.

BTRA Microbiology / Biotechnology laboratory is well equipped with modern instruments and the entire basic infrastructure that are needed to carry out routine microbiological work.

The department caters to the testing requirement of many national and international parties for assessment of textile materials using latest AATCC, ASTM and IS standards for home textiles and other related textile products. It also carries out antifungal activity assessment of textile materials specially carpets, floor coverings and packaging materials. The department also deals with testing of efficacy of antimicrobial finishing applied on high performance textiles directly and after repeated laundry washes. Bioburden test on export quality fabrics is also carried out.

Besides testing activities, it involves in spreading awareness among the young and aspirant Microbiologists about textile microbiology and related research through its workshops and training programmes.

BTRA undertakes following type of tests [Table – 1] at Microbiology/Biotechnology Test Laboratory. Also, in Table-2, specimen test results are provided for antibacterial activity for towels tested at BTRA.

List of Tests carried out at BTRA Microbiology Test Services

  • Antibacterial activity assessment of textile materials –Parallel St reak Method [AATCC –147]
  • Antibacterial finishes on textile materials [AATCC –100]
  • Antifungal activity, assessment on textiles material, mildew and rot resistance of textiles [AATCC –30]
  • Standard practice for determining resistance of synthetic polymeric materials to fungi [ASTM G 21]
  • Determining the antimicrobial activity of immobilized antimicrobial agents under dynamic contact conditions [ASTM: E2149]
  • Testing for antibacterial activity and efficacy on textile products [JIS L 1902]
  • Bioburden testing of textiles,
  • Sterility testing of treated material
  • Microbial limit tests
  • Detection of mildew /rot proof ness [MIL-STD-810 F Method 508.5.1-12/01/2000]
  • Evaluation of bacterial filtration efficacy of medical textile [ASTM F 2101]
  • Method for testing cotton cordages for resistance to attack by microorganisms [IS 1386]
  • Method for testing cotton fabric for resistance to attack by microorganism [IS 1389]
  • Assessment of antimicrobial activity of carpets (Qualitative and quantitative) [AATCC 174]

Medical Textiles Testing

Bombay Textile Research Association (BTRA) has been in the forefront of Textile Research, Consultancy, Testing of Textiles and Training for more than five decades. During this period, BTRA has always been pioneer in all frontier areas of Textiles. Likewise, BTRA is the first Textile Laboratory to set up a modern Microbiological Test facility and get the facility accredited for ISO 17025-2005.

Whatever may be the products, the efficacy and suitability of these products need to be evaluated. Laboratory evaluation, before the products are put to use, become an essential pre-requisite. This evaluation can be accomplished by testing the products behaviour against various microbiological organisms. Most of these products are used as infection control or barrier materials. It is absolutely necessary that the products be evaluated for the resistance to the microbes. At BTRA, we conduct various tests for the Textiles to evaluate their characteristics in terms of their resistance to the common microbes.

Whatever may be the products, the efficacy and suitability of these products need to be evaluated. Laboratory evaluation, before the products are put to use, become an essential pre-requisite. This evaluation can be accomplished by testing the products behaviour against various microbiological organisms. Most of these products are used as infection control or barrier materials. It is absolutely necessary that the products be evaluated for the resistance to the microbes. At BTRA, we conduct various tests for the Textiles to evaluate their characteristics in terms of their resistance to the common microbes.

TESTS CONDUCTED AT

Standard Test Number Details of Test Conducted

AATCC 147*

Antibacterial activity assessment of textile materials: Parallel Streak Method

This is a qualitative test to detect antibacterial activity of diffusible antimicrobial agents on treated textile materials. This is a widely used method for initial screening of bacteriostatic activity shown by different antimicrobial agents applied on textile materials.

AATCC 100*

Assessment of Antibacterial Finishes on Textiles Materials

AATCC 100 antimicrobial test method is a quantitative method for the evaluation of the degree of antibacterial activity of antibacterial finishes on textile material.
Microorganisms used are: Staphylococcus aureus and Klebsiella pneumoniae. Other microorganisms can also used upon request.

AATCC 30 Test 2*

Antifungal activity, assessment on textile materials: Mildew and Rot resistance of Textile materials Test-II – Agar Plate, Chaetomium globosum

This test is used for evaluating rot resistance of cellulose containing textile materials that will not come in contact with soil.

AATCC 30 Test 3*

Antifungal activity, assessment on textile materials: Mildew and Rot resistance of Textile materials Test-III – Agar Plate, Aspergillus niger

This test evaluates the growth of Aspergillus niger on textile specimens. The textile specimens are kept on the surface of an inoculated agar plate and incubation is carried out for 7 days.

AATCC 30 Test 4

Antifungal activity, assessment on textiles materials: Mildew and Rot Resistance of Textile materials Test –IV – Humidity Jar, Mixed spore suspension

The test determines the fungistatic effectiveness of treatments intended to control mildew and non-pathogenic fungal growth on articles or surfaces composed of textile materials intended for outdoor and above ground level use and which are usually water-proofed.

AATCC 174*

Antimicrobial Activity Assessment of New Carpets
AATCC 174 Part-1: A qualitative antibacterial assessment.

  1. AATCC 174 Part-2: A quantitative antibacterial assessment.
  2. AATCC 174 Part-3: A quantitative antifungal assessment.
This test method is designed to determine the antimicrobial activity of new carpet materials and consists of three procedures as mentioned above.

AATCC 90

Antibacterial Activity of Fabrics, Detection of: Agar Plate Method

This test method is used for the detection of bacteriostatic activity of fabrics using Agar Plate Method which depends on diffusion of the antibacterial agent through agar.

JIS L 1902*

Test for antibacterial activity and efficacy on Textile Products

This test method is a quantitative method (Absorption Method) for testing antibacterial property of fabrics.
It is designed to evaluate the Antibacterial activity of fabrics treated with antibacterial finish to prevent microbial growth and to kill microorganisms over a specific contact period.

JIS Z 2801

Antimicrobial products - Test for antimicrobial activity and efficacy for plastics and other antimicrobial coated hard surfaces. (Film Contact Test Method)

The JIS Z2801 method is quantitative test method to determine the antimicrobial efficacy and activity of hard surfaces of Plastics, Metals, Glass, ceramic, rubber, silicone and other non absorbent materials.

ISO 20645*

Textile fabrics – Determination of antibacterial activity – Agar Diffusion Plate Test

This test is a qualitative method to determine the effect of diffusible antibacterial finishes applied to woven, knitted and other flat textiles.

ISO 20743*

Textiles – Determination of antibacterial activity of antibacterial finished products

This test method is a quantitative determination (Absorption Method) of the antibacterial activity of antibacterial finished textile products.

ASTM E 2149*

Determination of the Antimicrobial Activity of Immobilized Antimicrobial Agents Under Dynamic Contact Conditions

The ASTM E2149 test method is designed to evaluate the antimicrobial activity of non-leaching antimicrobials treated specimens under dynamic contact conditions. This test method ensures good contact between the bacteria and the treated specimen by constant agitation of the test specimen in a challenge suspension during the test period.

ASTM G 21

Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi

This test method determines the effect of fungi on the properties of synthetic polymeric materials in the form of molded and fabricated articles, tubes, rods, sheets and film materials.

In-house Test Method

Evaluation of Bacterial Filtration Efficiency of Medical textiles

This test method is a quantitative method to measure the bacterial filtration efficiency (BFE) of medical face masks materials employing a ratio of the upstream bacterial challenge to downstream residual concentration.

IS 1622 & IS 5403*

Microbiological Examination of Water*

  • Total bacterial count (IS 1622) - Total bacterial count of water is estimated by performing standard plate count method, which is a direct measurement of the viable aerobic and facultative anaerobic bacteria.
  • Detection of coliforms (IS 1622) - Coliforms are detected in water by MPN Method.
  • Detection of E.coli (IS 1622) - E. coli are detected using Brilliant Green Bile Lactose Broth
  • Total fungal count (IS 5403) - Total Fungal count of water is estimated by determining viable yeast and mold count.

IS 1389

Methods for testing cotton fabrics for resistance to attack by microorganism by Humidity Chamber Method

The humidity chamber method is intended for determining qualitatively the susceptibility of the fabric to the growth of microorganisms associated with attack on cellulose.

ISO 11737 – Part I

Determination of a population of microorganisms on products

This test standard provides guidance for the enumeration and microbial characterization of the population of viable microorganisms on or in a medical device, component, raw material or package.

Bacteriological Analytical Manual

Aerobic Plate count & Yeast and Mold count

Aerobic plate count & Yeast and mold count is intended to indicate the level of total bacterial and fungal count respectively in a product.

ASTM E 2471

Standard Test Method for Using Seeded-Agar for the Screening Assessment of Antimicrobial Activity In Carpets

This test method qualitatively evaluates the presence of antibacterial and antifungal activity in or on carpets. ASTM E 2471 is used to assess the durability of the antimicrobial treatments on new carpets, and on those repeatedly shampooed or exposed to in-use conditions.

ASTM C 1338

Standard Test Method for Determining Fungi Resistance of Insulation Materials and Facings

This test method determines the relative ability of an insulation and its facing to support or resist fungal growth under conditions favorable for their development.

ASTM D 2020
Method A

Standard Test Methods for Mildew (Fungus) Resistance of Paper and Paperboard

This method covers the qualitative determination of mildew (fungus) resistance of paper and paperboard, particularly which have been given a fungus resistant treatment.

ASTM D 2574

Standard Test Method for Resistance of Emulsion Paints in the Container to Attack by Microorganisms

This test method covers the determination of the relative resistance of treated emulsion paints to attack in the container by organisms.

ISO 22196

Measurement of antibacterial activity on plastic surfaces

This test method is used for evaluating the antibacterial activity of treated plastic products.

ASTM D 4956

Standard Specification for Retro-reflective Sheeting for Traffic Control

Fungus resistance of retro-reflective sheeting can be tested as per this method.

* = Tests are under NABL scope