TE-BC251 NIOSH Bioaerosol Cyclone

The TE-BC251 is a wearable, multi-stage bioaerosol cyclone developed by the National Institute for Occupational Safety and Health (NIOSH) and manufactured by Tisch Environmental. It is designed to collect airborne viruses, including influenza and SARS-CoV-2 (COVID-19), for use in occupational and environmental health studies.

This compact, low-cost sampler is built for rapid deployment in evolving public health situations. Its three-stage design separates bioaerosols into individual collection compartments, allowing size-fractionated sampling and accurate retrieval of material at multiple cut points.

At a flow rate of 3.5 L/min, the BC251 meets the ACGIH/ISO respirable aerosol separation criteria commonly used in health-related aerosol measurements. It has been successfully used to capture airborne influenza virus in healthcare settings and from the coughs and exhalations of infected patients, and it can be operated with standard personal air sampling pumps.

For field work, the cyclone can be paired with an optional backpack to carry both the sampler and pump, and an available tripod stand supports fixed-location testing.

What’s Included with Each Sampler

Each TE-BC251 sampler package includes:

• (1) BC251 Cyclone
• (1) Heavy-duty carrying case
• (2) Falcon™ 15 mL conical centrifuge tubes
• (2) Fisherbrand™ nonsterile threaded-end microcentrifuge tubes without caps
• (2) Fisherbrand™ colored screw caps
• (1) Jar of O-ring grease
• (10) TE-BC251-5 EPDM O-rings, 1/16" width, dash number 027
• (1) Filter cassette

Collection Efficiency (BC251 Two-Stage Cyclone)

Collection characteristics for the BC251 at several flow rates are summarized below. Cut-off sizes refer to the 50% collection efficiency point; sharpness values are expressed as geometric standard deviation.

Flow rate (L/min)	1st stage 50% cut-off size (µm)	1st stage sharpness (σg)	2nd stage 50% cut-off size (µm)	2nd stage sharpness (σg)
2	4.9	1.48	1.7	1.68
3.5	4.1	1.51	1.0	1.59
10	2.1	1.44	0.41	1.56

Selected Literature Using NIOSH Cyclone Bioaerosol Samplers

The TE-BC251 and related NIOSH cyclone samplers have been used in a wide range of peer-reviewed studies on airborne viruses, respiratory aerosols, and environmental sampling in healthcare and community settings. Examples include:

• Fennelly KP (2020). Particle sizes of infectious aerosols: implications for infection control. Lancet Respir Med 8(9): 914–924. PubMed
• Gralton J et al. (2013). Respiratory virus RNA in airborne and droplet particles. J Med Virol 85(12): 2151–2159. PubMed
• Leung NHL et al. (2020). Respiratory virus shedding in exhaled breath and face mask performance. Nat Med 26(5): 676–680. PubMed
• Lindsley WG et al. (2016). Viable influenza A virus in airborne particles from coughs vs exhalations. Influenza Other Respir Viruses 10(5): 404–413. PubMed
• Lindsley WG et al. (2012). Quantity and size distribution of cough-generated aerosol particles. J Occup Environ Hyg 9(7): 443–449. PubMed
• Milton DK et al. (2013). Influenza virus aerosols in exhaled breath and the effect of surgical masks. PLoS Pathog 9(3): e1003205. PubMed
• Pan M, Lednicky JA, Wu CY (2019). Collection and detection of airborne viruses. J Appl Microbiol 127(6): 1596–1611. PubMed
• Yan J et al. (2018). Infectious virus in exhaled breath of symptomatic influenza cases. Proc Natl Acad Sci USA 115(5): 1081–1086. PubMed
• Binder RA et al. (2020). Environmental and aerosolized SARS-CoV-2 in hospital settings. J Infect Dis 222(11): 1798–1806. PubMed
• Birgand G et al. (2020). Air contamination by SARS-CoV-2 in hospitals. JAMA Netw Open 3(12): e2033232. PubMed
• Dabisch P et al. (2021). Temperature, humidity and simulated sunlight effects on SARS-CoV-2 in aerosols. Aerosol Sci Technol 55(2): 142–153. DOI
• Edwards DA et al. (2021). Exhaled aerosol increases with COVID-19 infection, age and obesity. Proc Natl Acad Sci USA 118(8): e2021830118. PubMed
• Lane MA et al. (2021). Bioaerosol sampling for SARS-CoV-2 in a referral center. Clin Infect Dis. PubMed
• Lednicky JA et al. (2020). Viable SARS-CoV-2 in air of a hospital room with COVID-19 patients. Int J Infect Dis 100: 476–482. PubMed
• Lednicky JA et al. (2020). Collection of SARS-CoV-2 from air in a university clinic. Aerosol Air Qual Res 20(6): 1167–1171. DOI
• Lei H et al. (2020). Environmental contamination with SARS-CoV-2 from persistently infected patients. Influenza Other Respir Viruses 14(6): 688–699. PubMed
• Ong SWX et al. (2021). Lack of viable SARS-CoV-2 in PCR-positive air samples from hospital rooms. Infect Control Hosp Epidemiol. PubMed