What are particle sizes presented in millimeters?

The size of contaminants and particles are usually described in microns, a metric unit of measure where one micron is one-millionth of a meter. There are 25,400 microns in one inch. The eye can see particles to about 40 microns.
The size of some contaminants and particles are indicated in the table below.

Particle	Particle Size (microns)
one inch	25,400
dot (.)	615
Eye of a Needle	1,230
Glass Wool	1000
Mist	70 - 350
Fertilizer	10 - 1000
Pollens	10 - 1000
Textile Fibers	10 - 1000
Fiberglass Insulation	1 - 1000
Human Hair	40 - 300
Human Hair	60 - 600
Hair	5 - 200
Cement Dust	3 - 100
Mold Spores	10 - 30
Starches	3 - 100
Red Blood Cells	5 - 10
Mold	3 - 12
Mustard	6 - 10
Antiperspirant	6 - 10
Textile Dust	6 - 20
Gelatin	5 - 90
Spores	3 - 40
Combustion-related Carbon Monoxide from motor vehicles, wood burning, open burning, industrial processes	up to 2.5
Fly Ash	1 - 1000
Coal Dust	1 - 100
Iron Dust	4 - 20
Smoke from Synthetic Materials	1 - 50
Lead Dust	2
Talcum Dust	0.5 - 50
Asbestos	0.7 - 90
Calcium Zink Dust	0.7 - 20
Paint Pigments	0.1 - 5
Metallurgical Dust	0.1 - 1000
Metallurgical Fumes	0.1 - 1000
Humidifier	0.9 - 3
Copier Toner	0.5 - 15
Liquid Droplets	0.5 - 5
Anthrax	1 - 5
Yeast Cells	1 - 50
Carbon Black Dust	0.2 - 10
Atmospheric Dust	0.001 - 40
Bacteria	0.3 - 60
Bromine	0.1 - 0.7
Lead	0.1 - 0.7
Radioactive Fallout	0.1 - 10
Rosin Smoke	0.01 - 1
Combustion	0.01 - 0.1
Smoke from Natural Materials	0.01 - 0.1
Oil Smoke	0.03 - 1
Tobacco Smoke	0.01 - 4
Viruses	0.005 - 0.3
Typical Atmospheric Dust	0.001 to 30
Pesticides & Herbicides	0.001
Carbon Dioxide	0.00065
Oxygen	0.0005
• one micron is one-millionth of a meter