Data Sheet

Oil Aerosol Reagents

ATI offers the highest quality, industry-standard oil reagents for use in conjunction with oil aerosol generators. Our reagents are used for in situ leakage testing and production quality control efficiency testing of high-efficiency air filters. ATI oil aerosol reagent products are suitable for government, nuclear, and FDA-regulated testing applications.


PAO-4 Reagent

Four-centistoke PAO (Chemical Abstract System ID 6864 9-12-7) reagents offer a U.S. Food & Drug Administration-approved alternative to DOP in FDA-regulated filter leakage testing applications. PAO is approved by the U.S. Army Surgeon General and is used by the United States military as a substitute for DOP in their filter and mask testing processes.

Ondina X 420 (EMEA Only)

Ondina X 420 is the latest version of Ondina, manufactured by Shell. Its CAS (Chemical Abstract System) Number is 1262661-88-0. The earlier Ondina EL version was listed in ISO 14644-3:2005 as one of the typical substances used to generate test aerosols, and X 420 continues to be widely used for in-situ testing of HEPA filters.


PAO-4 Ondina X 420 (EMEA)
CAS # 68037-01-4 or 68649-12-7 1262661-88-0
Boiling Point >316 ̊C (601 ̊F) >280 ̊C (536 ̊F)
Relative Density 0.819 @ 15.5 ̊C (60 ̊F) 0.816 @ 15 ̊C (59 ̊F)
Vapor Pressure <0.013 kPa @ 20 ̊C <0.5 Pa @ 20 ̊C
Vapor Density N/A >1
Solubility in Water Insoluble Insoluble
Appearance Colorless liquid Colorless liquid
Odor N/A Slight hydrocarbon
Melting Point / Freezing Point < -20 ̊C (-4 ̊F) N/A
pH N/A N/A
Flash Point 222 ̊C (432 ̊F) 225 ̊C (437 ̊F)
Method Used Cleveland Open Cup Cleveland Open Cup
Upper/Lower Flammability Limits UEL: N/A; LEL: N/A UEL: Typical 10% (V); LEL: Typical 1% (V)
Auto-Ignition Temp 343 ̊C (649 ̊F) > 320 ̊C (608 ̊F)
Available Sizes 1-gallon and 5-gallon containers 2-liter and 20-liter containers