particle counter @ maker annex, children's museum of houston

PARTICLE COUNTER @ CMOH Friday, April 4, 2014

www.sentryair.com

We visited the Maker Annex to…

…collect particle counts when Brent was 3D printing. We wanted to check on the performance of our previously installed air filtration equipment. We blogged about the visit.

NOTE: This was not a formal, controlled test in any sense of the word.

About particle size….

Particle size is measured in relationship to a meter. A micrometer, also referred to as a micron, is 1/1,000,000 of a meter; expressed as mm and µm. Particles too-small for the micron scale, sometimes called ultra-fine particles [UFP], are measured using the nano scale or nanometers. A single nanometer is 1/1,000,000,000 of a meter, expressed as nm. 3D printers produce particles in both scales.

Block diagram of measurement locations [asterisks]

3D printer

Sentry Air Model 300

airflow

Ambient air, in room, near idle printer 82,800

particles 0.3 µm or larger, per sq ft

HEPA Carbon

Laser cutter

Inside printer in operation 190,800

particles 0.3 µm or larger, per sq ft Filtered air exhaust,

outside fume extractor,

0 particles 0.3 µm

or larger, per sq ft

* *

Model 300 air volume: 350 CFM High 50 CFM Low

*

82,800 particles per cubic foot a few inches from the 3D printer’s exterior before the printer heated up.

82,800 190,800

190,800 particles per cubic foot inside the 3D printer cabinet while it was printing, fume extractor turned off.

Particle counter readings

0 particles per cubic foot, outside fume extractor, at the filtered air exhaust.

“HEPA filtration has been shown to be effective in capturing nanoscale particles and should be considered in situations where emissions may be regular, where processes are repeated, and where higher quantities are used in a way that may lead to emissions.”

page 58 NIOSH CIB 65

About HEPA filtration….

Ultrafine particle emissions from desktop 3D printers, by Brent Stephens, Parham Azimi, Zeineb El Orcha, Tiffanie Ramos Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, IL, USA, National Institute of Applied Sciences (INSA de Lyon), Lyon, France http://bit.ly/11RTixO Nanotoxicology: An Emerging Discipline Evolving from Studies of Ultrafine Particles, Environ Health Perspect. 2005 July; 113(7): 823–839, by Günter Oberdörster, Eva Oberdörster, and Jan Oberdörster http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257642/ CURRENT INTELLIGENCE BULLETIN 65 ,DEPARTMENT OF HEALTH AND HUMAN SERVICES, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Occupational Exposure to Carbon Nanotubes and Nanofibers http://www.cdc.gov/niosh/docs/2013-145/pdfs/2013-145.pdf

Sentry Air provides this information as courtesy to the Children’s Museum of Houston. We are not industrial hygienists. If you have concerns about air quality in the Maker Annex, we always recommend you discuss them with a certified Industrial Hygienist.