TESTING NEWS - Avian flu (Bird flu)
There is a great deal of concern regarding avian or bird flu and its potential impact on world health. This concern has raised questions about what products provide the best protection against the disease. In compliance with ISO 17025, Nelson Laboratories, Inc., (NLI) does not endorse or recommend any product, nor does it make recommendations on how to protect against avian influenza, SARS, or other diseases. This is the responsibility of health care providers, government regulatory agencies, and ultimately, the consumer. Independence and lack of bias are issues that we at NLI take very seriously.
NLI also cannot release information regarding client studies; this would be a breach of confidentiality. We recommend if there is a specific question about a product that appears to have been tested at NLI, that you contact the company or individual presenting the information to you and request a copy of the full NLI final report. This report will detail the general test method, the organism(s) used, and the data generated by the study. It is the responsibility of the company to appropriately interpret the data and apply it to their product claim/label where necessary.
Nelson Laboratories, Inc., can test a variety of products including face masks, gowns, and gloves, for protection against harmful diseases. However, due to the related health risks, NLI does not include organisms such as avian influenza, HIV, hepatitis B, hepatitis C, etc., in their test matrices. The following information is a detailed description of the viral and bacterial penetration testing capabilities available at NLI and how they relate to the avian flu.
The following is information regarding Nelson Laboratories test capabilities for face masks. Face masks in particular, can be tested according to several different methods. The following is an explanation of the methods used at Nelson Laboratories:
Bacterial Filtration Efficiency (BFE)
ASTM F2101-01 "Standard Test Method for Evaluating the Bacterial Filtration Efficiency (BFE) of Medical Face Mask Materials, Using a Biological Aerosol of Staphylococcus aureus", and Military Specification MIL-STD 36954C- Section 1.4 of the standard states, "This test method evaluates medical face mask materials as an item of protective clothing but does not evaluate materials for regulatory approval as respirators. If respiratory protection for the wearer is needed, a NIOSH-certified respirator should be used. A Relatively high bacterial filtration efficiency measurement for a particular medical face mask material doesn't ensure that the wearer will be protected from biological aerosols since this test method primarily evaluates the performance of the composite materials used in the construction of the medical face mask and not its design, fit or facial sealing properties." The test method uses Staphylococcus aureus to challenge the face mask materials. The bacterial culture suspension is pumped through a 'Chicago' nebulizer at a controlled flow rate and fixed air pressure. The constant challenge delivery, at a fixed air pressure, formed aerosol droplets with a MPS of approximately 3.0µ. The aerosol droplets are generated in a glass aerosol chamber and drawn through a six-stage, viable particle, Andersen sampler for collection. The collection flow rate through the test sample and Andersen sampler is maintained at 28.3 Liters per minute (Lpm) (1 cubic foot per minute (CFM)). The delivery rate of the challenge also produces a consistent challenge level of 1700-2700 CFU on the test control plates.
Additional information about Nelson Laboratories Bacterial Filtration Efficiency capabilities can be found at by clicking here.
Viral Filtration Efficiency (VFE)
The VFE test procedure was adapted from the Military standard MIL-M-36954C and ASTM F2101. The challenge organism used in this procedure is the phiX174 bacteriophage, which is one of the smallest known viruses at 27 nm (0.027µ) in size, has no envelope, and has icosahedral morphology. The bacteriophage suspension is pumped through a Chicago nebulizer at a controlled flow rate and fixed air pressure. The constant challenge delivery formed aerosol droplets with a MPS of approximately 3.0µ. The droplets are collected in a glass aerosol chamber and drawn through a six stage, viable-particle, Andersen sampler. The flow rate through the test sample and Andersen sampler is maintained at 28.3 Liters per minute (Lpm) (1 cubic foot per minute (CFM)).
Additional information about Nelson Laboratories Viral Filtration Efficiency capabilities can be found at by clicking here.
BFE and VFE at Increased Challenge Level
The difference between these methods and the previous methods is the use of all glass impingers (AGIs) in the collection process which allows a higher concentration of challenge to be delivered to each test sample. Bacterial Filtration Efficiency (BFE) and Viral Filtration Efficiency (VFE) show the effectiveness of medical face mask material in preventing the passage of aerosolized bacteria or viruses; expressed in the percentage of a known quantity that does not pass the medical face mask material at a given aerosol flow rate. The percent BFE or VFE reported is for general filtration of aerosolized bacteria; the Mean Particle Size of the aerosol is ~ 3.0µ.
The ASTM F 2100-01 standard states, "This specification does not apply to respiratory protection. If respiratory protection for the wearer is needed, a NIOSH-certified respirator, meeting the requirements of 42 CFR Part 84, should be used." As stated previously this method is testing the effectiveness of the face mask materials and does not address design, performance or facial fit. Results of these tests give a good general indication of how well the face mask material will filter aerosols of ~3.0µ in size. In order to make claims against specific organisms there usually needs to be data to back up those claims, since we do not test using the Avian flu virus any claims against such should be discussed with the appropriate regulatory agency.
NIOSH certification
The procedure for a NIOSH N95 certification is available at the following website address: http://www.cdc.gov/niosh/npptl/resources/certpgmspt/default.html.
For NIOSH N95 rating, the first step in the process is to pre-qualify your product. Nelson labs can help with this pre-qualification. We follow the procedures outlined in 42 CFR part 84 and in conjunction with the NIOSH approved procedures RCT-APR-STP-0057, 0058, 0059, 007, 003. The following tests are required for pre-qualification: 1) filtration efficiency, 2) inhalation resistance, 3) exhalation resistance, and 4) exhalation valve leak (when applicable).
1) For filtration efficiency, twenty respirators are conditioned for 25 hours at 85% RH and 38ðC. After conditioning, filters are put into a test system that passes a neutralized NaCl aerosol through the sample at 85 L/min. This aerosol has a particle size distribution with a count median diameter of 0.075± 0.02µ, a mass median diameter of 0.26µ, and a geometric standard deviation not exceeding 1.86µ as determined by the manufacturer with a scanning mobility particle sizer (SMPS). Masks are loaded with the NaCl until 200 mg contacts the filter. The maximum filter penetration that can occur to maintain a N95 rating is =5% (=95 % efficiency).
2 & 3) For airflow resistance two tests are performed, exhalation resistance and inhalation resistance. We determine the initial breathability of three masks, in both directions of exhalation and inhalation (42 CFR Part 84.180). Measurements are made with a 6 inch slant manometer. Initial Inhalation resistance cannot exceed 35 mm water and initial exhalation resistance 25 mm water.
4) For exhalation valve leak, three valves are removed from respirators and the leakage across the valve determined according to 42 CFR Part 84.182. Measurements are made with a digital soap film flowmeter and leakage cannot exceed 30 mL/min.
If each of the samples meets the N95 criteria, then you can send the test reports and an additional twenty nine respirators to NIOSH for official certification.
The Sodium Chloride (NaCl) aerosol challenge test is a more penetrating test than the BFE and VFE test. That means that the filtration efficiency results are lower than the BFE/VFE results. The particle size is ~ .26µ compared to 3.0µ for the BFE/VFE. NIOSH requires prequalification of any samples submitted to them for certification. For the Avian flu virus the CDC recommends, "for those that will come in contact with the virus or infected patients to use a fit-tested respirator, at least as protective as a National Institute of Occupational Safety and Health (NIOSH)-approved N-95 filtering facepiece (i.e., disposable) respirator."
Additional information about Nelson Laboratories NIOSH pre-qualification capabilities can be found by clicking here.
Surgical Gowns and Glove Testing
Nelson Laboratories also tests the barrier properties of surgical gowns, drapes and gloves. See more information on our testing capabilities at by clicking here. The procedures outlined above are the test capabilities that Nelson Laboratories can offer for viral and bacterial barrier testing. The results can give you an indicator of how your product might react to a harmful or infectious virus. If further information is needed on the test capabilities of Nelson Laboratories, please contact a member of our sales department at 800-826-2088 ext. 9300 or email sales@nelsonlabs.com.
Additional information about Avian flu can be found in the right hand column "Avian flu White Paper" written by Nelson Laboratories, Inc.
FDA PROVIDES ADVICE ON USE OF PROTECTIVE DEVICES IN CASE OF PANDEMIC FLU
The FDA recently published a notice providing advice for using personal protective equipment, such as masks and gloves, in case of a pandemic flu outbreak.
The notice lays out what protective equipment includes, an explanation of how it prevents the spread of infection, how to determine if the devices are cleared by the FDA, along with other advice.
According to the notice, devices such as surgical masks, medical gloves and surgical gowns will help prevent the spread of infection by acting as a barrier between infectious materials and the skin, mouth, nose or eyes. The notice also provides a website for consumers to use to determine if a particular device has been cleared by the FDA.
Furthermore, the notice answers such questions as: "Can I reuse personal protective equipment?;" "Is there any advantage to wearing double masks, double gloves, or double gowns to help prevent the spread of flu?;" and "If personal protective equipment is manufactured in an area affected by bird flu (avian influenza), is it safe to use?"
www.fda.gov/cdrh/emergency/flu_qa.html
U.S. Dept. of Labor, OSHA - Guidance for Protecting Workers Against Avian Flu
http://www.osha.gov/dsg/guidance/avian-flu.html
National Institute of Allergy and Infectious Diseases (National Institute of Health, NIH) - Focus on the Flu
http://www3.niaid.nih.gov/news/focuson/flu/default.htm
Virology.net - Taxonomy, Genus Influenza A (Orthomyxoviridae)
http://www.virology.net/Big_Virology/BVRNAortho.html
U.S. Centers for Disease Control and Prevention (CDC) - Avian Influenza (Bird Flu)
World Health Organization (WHO) - Avian influenza frequently asked questions
http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/index.html