Sulfur dioxide [SO2]: control of vapors in a lab setting

Our products are tested

We regularly test our products to measure their effectiveness at capturing specific hazardous substances so they cannot be inhaled.

These tests are called chemical efficiency tests.

The testing process and the test results are described  in an industrial hygiene report.

In the description of the testing process, we describe the location of sampling points and list the steps taken to challenge the air purification unit and the filters in it.

We courier the testing samples to a third-party, certified Industrial Hygiene Laboratory to analyze the samples and report what they find back to us.

Then we post the technical test process and the test results on our website and share them with our customers.

Our most recent efficiency test: SO2 vapors in a lab setting

In May, we blogged about the hazards associated with sulfur dioxide [also  called sulphur dioxide and SO2] which is encountered in many industrial settings. 

Recently, we completed an efficiency test of our Model SS-330-DCH, a thirty-inch wide ductless containment hood, configured with a standard carbon pre-filter and a speciality-blended 10-pound, activated carbon filter.The filter was treated to attract acid gases, like SO2 vapors, to it via a process known as chemisorption, which prevents the vapors from  dispersing into the broader area.


Test results

Lab analysis found that the tested configuration was 99.89% efficient at preventing SO2 vapors from escaping the hood.

The complete report is here:

All our efficiency tests can be found by clicking on our website’s Test Data tab.

If SO2 is in your workplace

Currently, PELs [permissible exposure limits] proffered by OSHA and NIOSH differ.

OSHA knows their existing regulated PELs are out of date and offers new, recommended PELs for some chemical exposures.

The following table is excerpted from OSHA’s Annotated Table Z-1.

If SO2 is part of your work environment, we urge you to investigate this new information from OSHA.

Want to talk about your acid gas process?

For information on acid gas filtration options for your chemical process, give us a call at 1.800.799.4609, email us at, or fill out this online form to have a Sentry Air Systems Applications Specialist contact you to discuss your process.