MERV RATING CHART
Standard 52.5 Minimum 
Efficiency Reporting 
Dust Spot 
Typical Controlled 
Typical Applications and 
Value
Efficiency
Arrestance
Contaminant
Limitations
Typical Air Filter/Cleaner Type
>99.999% eff. On .10-.20 pm 
20
n/a
n/a
< 0.30 pm particle size
Cleanrooms
Particles
> 99.999% eff. On .30 pm 
19
n/a
n/a
Virus (unattached)
Radioactive Materials
Particles
>99.99% eff. On .30 pm 
18
n/a
n/a
Carbon Dust
Pharmaceutical Man.
Particulates
17
n/a
n/a
All Combustion smoke
Carcinogenetic Materials
>99.97% eff. On .30 pm Particles
16
n/a
n/a
.30-1.0 pm Particle Size
General Surgery
Bag Filter- Nonsupported 
15
>95%
n/a
All Bacteria
Hospital Inpatient Care
microfine fiberglass or 
synthetic media, 12-36 in. deep, 6-
14
90-95%
>98%
Most Tobacco Smoke
Smoking Lounges
12 pockets
Box Filter- Rigid Style Cartridge 
Filters 6 to 12" deep m ay use 
13
89-90%
>98%
Proplet Nuceli (Sneeze)
Superior Commercial Buildings lofted or paper media.
12
70-75%
>95%
1.0-3.0 pm Particle Size
Superior Residential
Bag Filter- Nonsupported 
Legionella
microfine fiberglass or 
synthetic media, 12-36 in. deep, 6-
11
60-65%
>95%
Humidifier Dust
Better Commercial Buildings
12 pockets
Lead Dust
Box Filter- Rigid Style Cartridge 
Filters 6 to 12" deep m ay use 
10
50-55%
>95%
Milled Flour
lofted or paper media.
Auto Emissions
Hospital Laboratories
9
40-45%
>90%
Welding Fumes
Pleated Filters- Disposable, 
8
30-35%
>90%
3.0-10.0 pm Particle Size
Commercial Buildings
extended surface area, thick with 
cotton-polyester blend media, 
Mold Spores
cardboard frame
7
25-30%
>90%
Hair Spray
Better Residential
Cartridge Filters- Graded density 
viscous coated cube or pocket 
Fabric Protector
filters, synthetic media
6
<20%
85-90%
Dusting Aids
Industrial Workplace
Throwaway- Disposable  
Cement Dust
synthetic panel filter.
5
<20%
80-85%
Pudding Mix
Paint Booth Inlet
Throwaway- Disposable 
4
<20%
75-80%
>10.0 pm Particle Size
Minimal Filtration
fiberglass or synthetic panel filter.
Pollen
3
<20%
70-75%
Dust Mites
Residential
Washable- Aluminum Mesh
Sanding Dust
2
<20%
65-70%
Spray Paint Dust
Electrostatic- Self charging 
Textile Fibers
Window A/C Units
woven panel filter.
1
<20%
<65%
Carpet Fibers

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