28 replies to this topic

[NicoD]

Hello everyone, this is my first post here, thank you very much in advance :)

 

I would be grateful if you could help me to interpret some data.

I'll write in bullet points and numbered lists to be more clear.

 

Food production facility, dry pet foods (mainly oven dried beef, chicken, and potatoes treats).

CCP1: water activity less than 0.55 to 0.60 (depends by the products), so very dry products.

 

The main difficulty for me to interpret the results from the external lab is that when they delivered the swab kit it wasn't the classic 25 or 100 cm2 frame with cotton swabs.

We had a sterile impregnated sponge to pass over the hands, or the surfaces, or to shoot with compressed air (to test the air).

 

So, in the results, I don't have an actual CFU/cm2 but CFU/swab. ????

 

1) Hands swabs

Swabbed the sponge on supposedly clean gloves DURING production:

• Finished products, while packaging

• While checking the CCP1 on finished products

 

Results:

 

Gloves while packaging:

 

Employee 1:

Aerobic Colony Count 1200 CFU/swab

Coliform (Petrifilm) <10 CFU/swab

E. coli (Petrifilm) <10 CFU/swab

 

Employee 2 (same order as above):

790 CFU/swab

<10 CFU/swab

<10 CFU/swab

 

 

Gloves while measuring the CCP1:

 

Aerobic Colony Count 1600 CFU/swab

Coliform (Petrifilm) 160 CFU/swab

E. coli (Petrifilm) <10 CFU/swab

 

 

Compressed air:

Several samples from different rooms.

They are all very similar, in this range:

 

Aerobic Colony Count <10 CFU/swab (only 1 sample had 25 CFU/swab... how about this one too?)

Coliform (Petrifilm) <10 CFU/swab

E. coli (Petrifilm) <10 CFU/swab

 

 

Tap water (in this case it's easier, it's per mL):

Aerobic Colony Count HGMF 60 CFU/mL

Coliform HGMF <1 CFU/mL

E. coli HGMF <1 CFU/mL

 

 

 

What do you think about these results?

 

Thank you very much, I really appreciate your help, especially for the mistery of the hands without actual measured area.

 

[Charles.C]

Hi drywood,

 

IMHO, the data is unfortunately meaningless for reference purposes  unless there is an agreed prodedure for what constitutes a "swab".

 

I have seen count / "swab" used as a limiting (unit) requirement but the associated area was simultaneously defined.

 

PS - Welcome to the Forum ! 

[NicoD]

Thank you very much Charles :)

 

Ah I'm Nico, nice to meet you (I'm going to change nickname right now).

 

Yes that's what I was thinking.

 

In your opinion, in order to just have some "data" to reason with at our SQF audit next week, since I completely swabbed the hand, aseptically, palm, top, fingers, fingertips, around fingers, etc... (with gloves)... How about if I make an online research to see an approx. average human hand surface area and use that?

 

Or, I can have the same employee with same type of glove submerging the hand until the level I swabbed in measured volume of water, see the difference, and convert the water volume increased in cm2 somehow... any suggestion to make this "conversion"?

 

Finally, let's pretend I will get an estimated swabbed area, how am I going to use the swab data?

 

For example, if the sponge swabbed 200 cm2 of gloved hand.... how would I convert from CFU/swab to CFU/cm2?

 

Can I just consider the sponge like a normal cotton swab, so I will just have to divide the CFU over 200?

 

Finally, how about water and air compressed?

 

Sorry for all these questions, thank you very much!

 

N.

[NicoD]

I can't change id anymore, I had already changed before and I'm allowed only 1 every 365 days

[NicoD]

Ok so, I was thinking:

 

Most probably the lab submerged the sponge in a buffer, shaked, and then poured the plates from the bottle. So I simply considered the sponge like a cotton swab.

 

I found a study about the average surface area of human hands in a group of 65 Koreans:

 

 

Lee, J. Y., Choi, J. W., & Kim, H. (2007). Determination of hand surface area by sex and body shape using alginate. Journal of Physiological Anthropology, 26(4), 475-483.

 

On purpose I selected the smallest hand: 297 cm2 of a female in the Lean females group. Even though our employee is a slightly overweight person, and for sure has bigger hands than the small lean korean one.

I did this on purpose just in case, in order to obtain the highest reading possible in terms of CFU/cm2

 

I divided the CFU/swab results by 297 cm2.

 

Here are the results:

 

Employee 1:

Aerobic Colony Count:

1200 CFU/swab

1200 CFU / 297 cm² = 4.0 CFU/ cm²

 

Coliform:

<10 CFU/swab

<10 CFU / 297 cm² = <0.03 CFU/ cm²

 

E. coli:

<10 CFU/swab

<10 CFU / 297 cm² = <0.03 CFU/ cm²

 

 

^{Employee 2:}

Aerobic Colony Count:

790 CFU/swab

790 CFU / 297 cm² = 2.7 CFU/ cm² (Accepted limit: 100 CFU/cm²)

 

Coliform:

<10 CFU/swab

<10 CFU / 297 cm² = <0.03 CFU/ cm² (Accepted limit: absent/cm²)

 

E. coli:

<10 CFU/swab

<10 CFU / 297 cm² = <0.03 CFU/ cm² (Accepted limit: absent/cm²)

 

 

I think these are pretty good readings...

 

Do you think the method used in translating the results is acceptable?

 

I remember I swabbed the whole hand surface (palm, top, between fingers, etc...).

 

Or should I further divide the swabbed area by 2, pretending I missed half of the spots of the hand, and obtaining a result even higher, in order to satisfy our auditor?

 

Thanks

[Charles.C]

Thank you very much Charles :)

 

Ah I'm Nico, nice to meet you (I'm going to change nickname right now).

 

Yes that's what I was thinking.

 

In your opinion, in order to just have some "data" to reason with at our SQF audit next week, since I completely swabbed the hand, aseptically, palm, top, fingers, fingertips, around fingers, etc... (with gloves)... How about if I make an online research to see an approx. average human hand surface area and use that?

Yes, the surface area of an average hand should work. You could probably just measure  estimate a few workers' hands also and take an average. (Ideally the data should be correlated to the person swabbed of course).

 

Or, I can have the same employee with same type of glove submerging the hand until the level I swabbed in measured volume of water, see the difference, and convert the water volume increased in cm2 somehow... any suggestion to make this "conversion"?

 

Finally, let's pretend I will get an estimated swabbed area, how am I going to use the swab data?

 

For example, if the sponge swabbed 200 cm2 of gloved hand.... how would I convert from CFU/swab to CFU/cm2?

Calculate (CFU/swab) / 200 >> cfu/cm2

 

Can I just consider the sponge like a normal cotton swab, so I will just have to divide the CFU over 200?

 

Finally, how about water and air compressed?

See below

 

Sorry for all these questions, thank you very much!

 

N.

Hi Nico,

 

ACC/Coliform/E.coli Limits for surfaces may vary with product/process/location etc, have a look at the Excel sheet in this post -

 

http://www.ifsqn.com...ces/#entry60958

 

the various Coliform/E.coli  "<" data numbers you have usually means not detected.

 

A typical hand figure is < 100/cm2 but it  "all depends". If max 100/cm2 yr results look quite good (and similarly data for Coliform/E.coli although some critics might expect a lower detection level to have been used, eg <1 /cm2). Perhaps you have a clean team/environment (looks like RTE production).

 

I don't quite understand what the data for air/water are referring to ? Air - Swabs of what ? Water - direct sample of the liquid ?

 

afaik SQF for compressed air are typically concerned with counts on 'settle" plates and filtration performance.

 

PS - sorry, our posts overlapped.

I doubt that yr SQF auditor will be particularly "picky" about hand area accuracy if the figure looks adequately low.

[NicoD]

Great, thanks so much Charles! I appreciate your help.

 

As you can see in the post I posted probably right while you were posting yours, I retrieved reliable data about hand surface.

 

For the air compressed, I literally (and aseptically) shot compressed air with the air gun over the sponge for 10 seconds.

 

Probably, I could get the specs of the air compressor in terms of air volume / second.

 

For example, if it is 100 cm3 of air / second, I can divide the results obtained (CFU/swab) by 10 (10 seconds) and I can know the CFU/cm3 of compressed air.

 

Does it make sense?

 

The problem is finding an accepted standard!!!

 

But the important is that our previous reading of compressed air was 150 CFU and 190 CFU (/swab) in 2 air compressors.

Then we installed new filters in the compressors and now we are <10.

This should show to the auditor that the corrective action worked.

 

 

The water was collected in a lab predisposed sterile bottle (with dry media already inside, I think either PO4 or peptone) and sent to the lab.

[Charles.C]

Great, thanks so much Charles! I appreciate your help.

 

As you can see in the post I posted probably right while you were posting yours, I retrieved reliable data about hand surface.

 

For the air compressed, I literally (and aseptically) shot compressed air with the air gun over the sponge for 10 seconds.

Unfortunately, IMEX there is a standardized procedure for this using specific instruments. Factories often have to use labs with the tools.

 

Probably, I could get the specs of the air compressor in terms of air volume / second.

 

For example, if it is 100 cm3 of air / second, I can divide the results obtained (CFU/swab) by 10 (10 seconds) and I can know the CFU/cm3 of compressed air.

 

Does it make sense?

yr procedure may not be auditorially acceptable.

 

The problem is finding an accepted standard!!!

See link below although the situation is as equally subjective as for hand swabbing

 

But the important is that our previous reading of compressed air was 150 CFU and 190 CFU (/swab) in 2 air compressors.

Then we installed new filters in the compressors and now we are <10.

This should show to the auditor that the corrective action worked.

 

 

The water was collected in a lab predisposed sterile bottle (with dry media already inside, I think either PO4 or peptone) and sent to the lab.

 

Hi Nico,

 

There are several long discussions over SQf's requirements for compressed air (CA) on this forum. Not a simple topic.

 

See the excel sheet in post linked below plus the surrounding thread discussion.

 

http://www.ifsqn.com...ent/#entry81054

 

For RTE products, the expectation is likely to be more demanding than non-RTE, see the thread sub-linked in post 2(Snookie) of the above thread.

 

The water data will probably be evaluated against Canadian limits. The Coliform/E.coli results look OK.  No idea for plate count.

 

Based on various reported CA experiences on this forum, It is not entirely obvious what the SQF auditors routinely expect so perhaps yr swabbing procedure for CA will work for you. hope so.

[NicoD]

Great, thank you very much Charles!

 

Your works are excellent and very useful!!

 

The only thing I couldn't find is:

 

"the thread sub-linked in post 2 of the above thread."

[Charles.C]

Great, thank you very much Charles!

 

Your works are excellent and very useful!!

 

The only thing I couldn't find is:

 

"the thread sub-linked in post 2 of the above thread."

 

Hi Nico,

 

Sorry, was wrong link in post 8 of present thread. Now corrected.

 

(should point to post 8 in new thread with an excel sheet + several attachments, etc at bottom of post).

[NicoD]

It's okay.

On the contrary, thanks again!!!

Wow useful resources.

The only thing is the RTE topic

 

"the thread sub-linked in post 2 of the above thread."

 

I still can't find it. I only found a lot of GREAT resources about compressed air, but not the RTE topic you mentioned.

 

Thanks again

[Charles.C]

It's okay.

On the contrary, thanks again!!!

Wow useful resources.

The only thing is the RTE topic

 

"the thread sub-linked in post 2 of the above thread."

 

I still can't find it. I only found a lot of GREAT resources about compressed air, but not the RTE topic you mentioned.

 

Thanks again

 

Hi Nico,

 

Sorry, my poor English.

 

I was suggesting to look at that thread since it discusses in detail the (SQF) necessity (or not) of installing ultra-high (sterile)  filtration systems.

SQF Guidance seems to like sterile air filters for all situations, some other references evaluate/recommend on a risk basis (also, from memory, permitted by SQF) which generates a whole range of filter efficiencies/equipment. The latter approach has RTE foods / direct air impact scenarios at the top end. (In fact some manufacturers seem to use SQF to justify installing ultra-high Grade filters while others note the possibility of overkill).

 

How upset SQF auditors are if they actually do encounter any non-sterile filter set-ups remains unclear.

[NicoD]

Great, don't worry :)

Thank you very much, I really appreciate your comprehensive advices!!!

[Simon]

I can't change id anymore, I had already changed before and I'm allowed only 1 every 365 days

 

I can change your username to Nico if you like, let me know.

 

Regards,

Simon

[NicoD]

Great! Thank you very much Simon, I would appreciate that :)

[w.weber]

Hello,

please have in mind, whether you are diluting / soaking the sponge in a solution. We are using swabs, putting into 10ml of solution and from this 10ml we are using 1ml for the plate. So if you are detecting 120 CFU in this 1 ml, it means you have had about 1200 cfu in ths soaking solution. This value can be divided by the surface afterwards to get correct numbers. 

Because usually not the full solution amount is used for preparation of the plates.

 

Yours

Werner

[NicoD]

Thank you very much Werner!

I appreciate your advice.

We send the sponge to the external lab. It's the lab kit actually. So it's up to them to calculate the dilutions.

 

UPDATE for everyone:

• We used the average surface area of a human hand, since I swabbed the whole hand surface

• We've got 97% and 100% for the SQF and Costco audits respectively

 

UPDATE for Simon:

Thank you very much for changing the username!!! :)

 

Have a great day everyone!

[elisa05]

Hai! how to set the acceptable limit? is there any standard on it?? 

[Charles.C]

Hai! how to set the acceptable limit? is there any standard on it?? 

 

Hi Elisa,

 

Try the link in Post 6 above. (food contact surfaces)

[elisa05]

Hi Elisa,

 

Try the link in Post 6 above. (food contact surfaces)

Hai, sorry is there any standard to refer to? 

[Charles.C]

Hai, sorry is there any standard to refer to? 

 

If you mean a Global Standard - No.

[elisa05]

If you mean a Global Standard - No.

If so, how can we know the acceptable limit? 

[Charles.C]

If so, how can we know the acceptable limit? 

Post 19.

[elisa05]

Post 19.

Hai Charles, i new in forum. What you mean by post 19? Sorry. 

[Charles.C]

Hai Charles, i new in forum. What you mean by post 19? Sorry. 

 

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