Off-gas testing

Off-gas testing is done on assemblies going into sensitive particle detection equipment.  It is critical that these assemblies do not emit any gases or vapours from the assembly process that would corrupt the analysis done by the machine.

For greater understanding visualize a similar liquid – water in a swimming pool.  Imagine dropping a sugar cube into a body of water the size of 3 Olympic size swimming pools. That is the level of sensitivity required for off-gas testing


Macfab’s off-gas testing is isolated within our ISO 7 cleanroom

Even with that barrier in place, our company policy is very strict on fragrance coming into the manufacturing space.  If a person were to wear perfume, cologne, or a scented deodorant into the manufacturing floor, the off-gas test might be contaminated, which is a risk we protect against.

Off-gassing can be caused by several reasons:

  • Physical evaporation of volatile’s trapped inside the polymer volume. For example. evaporation of residual solvents or adhesives
  • Evaporation of the solvents from the external surface of the part such as drying of paint or varnish
  • Slow chemical reactions inside a silicone sealant curing

When is Off-Gas Testing Required?

This testing requirement can be found in many industries. Parts going into medical and pharmaceutical machinery need this level of validation. Macfab does this testing to ensure the parts once installed in the machinery will not contaminate people or products. Security and defense products that utilize gas-spectrometry to determine the safety of packages cannot afford to have gases venting from seals generate false positives. We inspect assemblies to verify any seals or gaskets are not emitting gasses. For space components, NASA maintains a standard (NASA-STD-6001) to make sure gasses do not accumulate within a spacecraft.

How is Off-Gas Testing Done?

Macfab offers tests from a few hours to a couple of days. The tests are performed at normal or elevated temperatures. Relative humidity of the test air in contact with the sample can be varied from 0% to ambient, and up to 80% RH. Gases and vapors emitted from the sample can be tested as “total vapors” or individually. If the chemical composition of the emitted vapor is unknown, we can identify the individual vapors.

Component Sizes

Macfab’s off-gas testing chambers can accommodate a large range of parts. Most sub-assemblies receiving off-gas testing are small and easily fit into the chamber. With Macfab’s fabrication work including panels and structures for satellites, Macfab can test enclosures the size of a shoebox comfortably.

Macfab’s engineers and quality experts are prepared to review your application’s requirements and work on determining validation tests. We look forward to discussing this highly critical testing procedure for your parts with your experts.