Compressed Air coming into contact with Class II Medical Device

[Cheeky on tour]

Hi,

We are making a sterile class IIa product but the manu site blow air onto the product to open the packaging. I am unable to find out where and what filter size I should insist they have fitted to their machine? It is not manufactured in a cleanroom but a controlled area.

New to this but keen as mustard

 

[somashekar]

Re: Compressed air coming into contact with medical device

When the activity is happening in a controlled area, which is not a cleanroom to any classification, what is controlled in the area about the air quality is an unanswered question.
When this same air is being blown (by the packaging machine to open up the packaging pouch to let the product inside the pouch prior to sealing ... I guess) you may not be creating any adverse effect
If you know your air quality in terms of bioburden and particulate matter count, and your validation of sterilization and if it is meeting your requirement, the system seems to be under control.
Please let us know if the air being blown is from a separate pneumatic line from outside the manufacturing area. Here, the moisture content of the air can be a big culprit.

 

[MIREGMGR]

I agree with Somashekar's comment. Compressed air systems easily can have high bioburden. Was the pre-sterilization bioburden evaluation as part of your sterilization process validation done after the operation in question?

Compressed air system bioburden contributions also can change rapidly because of the usual presence of moisture, traces of lubricating oil as a carbon source, elevated oxygen levels, and seed-bacterial presence on dust in the feed air to the compressor. A knowledgable microbiological auditor might challenge your sterilization validation based on this, because it would be impossible to show that the pre-sterilization bioburden evaluation was of a stable condition, and was representative of worst case.

 

[SteveK]

When considering "medical air" an old copy of NFPA 99 I have indicates filters:

"Be sized for 100 percent of the system peak calculated demand at design conditions and be rated for a minimum of 98 percent efficiency at 1 micron or greater."

It also indicates that 'instrument air supply' filters:

"Be rated for a minimum of 98 percent efficiency at 0.01micron."

I don't know if this helps.

Steve

 

[MIREGMGR]

The problem with that kind of filter spec is, what really matters is not the filter specs but the bio-status of the throughput-air.

So, you'll have to write a rationale for what that bio-status must be per the filter, or has been tested to be.

This chart http://www.filterair.info/literature/Files%2FBacteriaFungusVirusChart.pdf provides relevant information. A 0.01um filter (i.e. "instrument grade") thus might be regarded as blocking passage of most organisms, assuming provision of a pre-filter to keep water, oil mist and significant particles out of the final filter.

But, what does "98% efficiency" actually mean? Obviously a filter that passes two percent of incident organisms is next to useless.

And, can such a filter be used in a high-burst-flow application such as pouch inflation? And, how frequently would such a filter have to be changed?

 

[mlee97]

Instead of relying on filtration of the air, why don't you sterilize it before blowing with a heating system? Perhaps you could use a heated pneumatic cylinder to puff the bags.

 

[MIREGMGR]

I'd think a microbiology auditor might have difficult-to-answer questions about how you validated such an approach, unless you develop the process to conform to ISO 20857:2010, the standard for dry heat sterilization.

The rapid method under that standard calls for heating the substance to be sterilized to 190C, then holding it at that temperature for six minutes. The validation would have to show that the air was assuredly well mixed so that all of it would reach or exceed that temperature for that time, every time the process was used.

 

[mlee97]

I'm totally stepping out of my field of expertise, but using Gay-Lussac's Gas Law calculator, one can easily cross the 190 c, evenly and instantly, with the piston pressure release cooling the output so as not to scorch the bags. I would think that hitting higher pressures and temperatures would be recognized as sufficient in a gov't spec. somewhere.

 

[Ronen E]

There's an additional aspect that hasn't been discussed here yet. The use of compressed air blasts is likely to introduce static charges to the packaging materials, and thus cause attraction of all sorts of particles from the (un?)controlled environment. This would render the compressed air sterility / cleanliness practically irrelevant.

Cheers,
Ronen.

 

[dgriffith]

There's an additional aspect that hasn't been discussed here yet. The use of compressed air blasts is likely to introduce static charges to the packaging materials, and thus cause attraction of all sorts of particles from the (un?)controlled environment. This would render the compressed air sterility / cleanliness practically irrelevant.

Cheers,
Ronen.

The blow-down air in our ESD safe work area is treated and ESD safe for circuit boards/surface mount component applications. I'm sure a similar method could be used to treat the clean air at the nozzle.