20 replies to this topic

[hygienic]

Dear All ;

In our production area , such as Hot kitchen ,or cold kitchen there is a very good ventelation (AC) , the fresh cold Air coming to the said area via the Air wents , So I just want to be sure with regards the Air if it is free of Bacteria, Is there any microbiological test can be done to know exactly that Air free from Bacteria and no harm while breathing ,Can we test the Air by using a normal test (Petri dish includes the media of a coliform or staph or TPC ?
Please I want to clarify this

Regards
Hygienic

[Dr Ajay Shah]

There are low volume air samplers that you can hire or get a certified laboratory to conduct a test on your site for TVC using nutrient agar. The food microbiological laboratory can also guide as to which agar you can use.

I hope the following article is useful to you particularly the end of the Table on page 219 of the article:

http://www.ceers.org...2/n3/203004.pdf


Regards

Ajay

[SriramB]

Dear All ;

In our production area , such as Hot kitchen ,or cold kitchen there is a very good ventelation (AC) , the fresh cold Air coming to the said area via the Air wents , So I just want to be sure with regards the Air if it is free of Bacteria, Is there any microbiological test can be done to know exactly that Air free from Bacteria and no harm while breathing ,Can we test the Air by using a normal test (Petri dish includes the media of a coliform or staph or TPC ?
Please I want to clarify this

Regards
Hygienic

Hi ,

The short answer is that you can test your air quality using ' settle plates' (basically petri dishes with non - selective agar). This is a cheap and effective solution, but the data provided is not quantitative ( sometimes the plates can be over colonized if there is a bad patch..). but still this is a good method for low risk areas and to provide early warning signs etc.
'
But, for applications in kitchens etc, you probbaly should look at proper microbological sampler, which normally draws a set volume of air through a filter or as a laminar flow over a prepoured agar plate. The advantages are numerous, but you now have a repeatable process which you can use to analyse your air data quantitatively.

It is great you are looking at establishing the air quality in your factory, as the regulations and standard now seem to be requiring this as means of monitoring GMP.

p.s. There are numerous models available and suggest you contact your local suppliers.

Cheers,
SriramB

[faisal rafique]

Dear,

Air Sampler is good but it may be done by exposing nutrient agar petri dish for 5-10 min in target area.
Faisal Rafique

Edited by faisal rafique, 01 April 2011 - 09:13 AM.

[konmar]

Dear hygienic,

if the air goes throught 3 filters and your microbiological analysis of the prepared food are ok why you want to check the air microbes? But I remember (faidly) that in school they were demostrating one device for check the microbes of the air.

BR

[maricmargot]

Hi Hygienic,

I know tree two methods to check the quality of air.

1. first method is from a book written by Doctor Savu Veterinary and the methodology is:

- to put for each microorganism (TPC or Y&M) the Petri dishes open in zone where we want to take sample of air;
- the time for exposure is 10 minute for each type of microorganism;
- the Petri dishes must to have the special medium for each type of m.o (total plate count/yeast and moulds);
- we must to put 2 plate for each type of microorg in the same time
- the formula is:

N = A x 50

Where:

N –microorganism number per 1 cubic meter air
A - microorganism number per plate (what we see on the plate after incubation)
50 – is a factor number

For example: if you take the air in the same time 2 plate the result is:

Propose we find on the first plate of TPC 4 colony and on the second 10 colony TPC the calculation is:

4+10 = 14 colony for 2 plates take in the same time
14:2 = 7 colony per plate

N = 7 x 50 = 350 microorganism number per cubic meter of air

2. The second method is use by medical laboratory and use the formula for Omelianski

The methodology is:

- to put for each microorganism (TPC or Y&M) the Petri dishes open in zone where we want to take sample of air;
- the time for exposure is from 5 until 30 minute for each type of microorg;
- the number of the plate for each mo deepened from the size of the room, the air circulation, the personal circulation;
- the Petri dishes must to have the special medium for each type of m.o (total plate count/yeast and moulds);
- the formula is:

N = 10000 x A/S x K

Where:

N –microorganism number per 1 cubic meter air

A - Microorganism number per plate (what we see on the plate after incubation)

10000 – factor
S – Plate surface ( 9 or 12 mm)
K – Exposure time

3. The third method is with same apparatus and the calculation is Feller formula. I(We will find on the google)

The ISO have a standard form 2009 for air: ISO 16000-18 Indoor air - Part 18: Detection and enumeration of moulds - Sampling by impaction Mould spores are widely distributed in the outdoor environment and, therefore, occur in varying concentrations also indoors.

This is the abstract of standard:

Growth of moulds in indoor environments, however, should be considered a hygienic problem because epidemiological studies have revealed that dampness and/or mould growth in homes and health problems affecting the occupants are closely related. Standardized methods for sampling, detection and enumeration of moulds including standards for sampling strategies are important for comparative assessment of mould problems indoors. During sampling the particles in the air stream impact on the agar surface - due to their inertia - when the air flows bend to bypass the solid surface. Airborne moulds are thereby collected directly on the agar plates which are situated accordingly. Slit samplers or sieve samplers can be used and are available commercially). After sampling the mould spores are cultivated and counted. This procedure is described in DIN ISO 16000-17

All the best,
maricmargot

[hygienic]

Hi Hygienic,

I know tree two methods to check the quality of air.

1. first method is from a book written by Doctor Savu Veterinary and the methodology is:

- to put for each microorganism (TPC or Y&M) the Petri dishes open in zone where we want to take sample of air;
- the time for exposure is 10 minute for each type of microorganism;
- the Petri dishes must to have the special medium for each type of m.o (total plate count/yeast and moulds);
- we must to put 2 plate for each type of microorg in the same time
- the formula is:

N = A x 50

Where:

N –microorganism number per 1 cubic meter air
A - microorganism number per plate (what we see on the plate after incubation)
50 – is a factor number

For example: if you take the air in the same time 2 plate the result is:

Propose we find on the first plate of TPC 4 colony and on the second 10 colony TPC the calculation is:

4+10 = 14 colony for 2 plates take in the same time
14:2 = 7 colony per plate

N = 7 x 50 = 350 microorganism number per cubic meter of air

2. The second method is use by medical laboratory and use the formula for Omelianski

The methodology is:

- to put for each microorganism (TPC or Y&M) the Petri dishes open in zone where we want to take sample of air;
- the time for exposure is from 5 until 30 minute for each type of microorg;
- the number of the plate for each mo deepened from the size of the room, the air circulation, the personal circulation;
- the Petri dishes must to have the special medium for each type of m.o (total plate count/yeast and moulds);
- the formula is:

N = 10000 x A/S x K

Where:

N –microorganism number per 1 cubic meter air

A - Microorganism number per plate (what we see on the plate after incubation)

10000 – factor
S – Plate surface ( 9 or 12 mm)
K – Exposure time

3. The third method is with same apparatus and the calculation is Feller formula. I(We will find on the google)

The ISO have a standard form 2009 for air: ISO 16000-18 Indoor air - Part 18: Detection and enumeration of moulds - Sampling by impaction Mould spores are widely distributed in the outdoor environment and, therefore, occur in varying concentrations also indoors.

This is the abstract of standard:

Growth of moulds in indoor environments, however, should be considered a hygienic problem because epidemiological studies have revealed that dampness and/or mould growth in homes and health problems affecting the occupants are closely related. Standardized methods for sampling, detection and enumeration of moulds including standards for sampling strategies are important for comparative assessment of mould problems indoors. During sampling the particles in the air stream impact on the agar surface - due to their inertia - when the air flows bend to bypass the solid surface. Airborne moulds are thereby collected directly on the agar plates which are situated accordingly. Slit samplers or sieve samplers can be used and are available commercially). After sampling the mould spores are cultivated and counted. This procedure is described in DIN ISO 16000-17

All the best,
maricmargot

Dear Maricmagot;

Many thanks for your effort you and other members posted in this topic , I will follow method No 2 ,but Do you know the best media used for detection of Yeast & Molds ? Thanks again really helpful .


Regards
Hygienic

[s kumar]

thx for the information. Are these procedures available on links so that I can use the procedure and keep the data for validation?

[Gourav]

Thanks for sharing the method.
Can you please share the standard also. What is max aloowed limit of no of beacteria/Y & M / per unit volume of air

Thanks

[AS NUR]

I know one device to do Air Quality Test for MIcro,MAS (Merck Air Sampler) from Merck. May Be other supplier have different Brand.

rgds

AS Nur

[hygienic]

Thanks for sharing the method.
Can you please share the standard also. What is max aloowed limit of no of beacteria/Y & M / per unit volume of air

Thanks

Dear;

I got the standard while I was asking about the procedure , its 500 /cfu for both TPC and Y/M exposure time 15 minutes

Regards

Edited by hygienic, 13 May 2011 - 02:41 PM.

[srose]

Happy New Year to all IFSQN members.

 

Does anyone know the reference for the standard '500 /cfu for both TPC and Y/M exposure time 15 minutes' provided by hygenic in the post above? I know the post is a bit dated but I am searching for a Y&M standard for indoor air quality in a food processing facility that has a wet process.

 

Thanks

[fgjuadi]

I don't know where that figure came from, but here are a couple current links  -

 

This one lists no limits and has very little information on micro (sorry!), but it will tell you all about IAQ sampling and parameters

 

http://www.fss.txsta...AQ_Handbook.pdf

 

This one lists limits in terms of OSHA and employee exposure, which is really the only data I could find out there  - https://www.osha.gov.../otm_iii_2.html

1. Airborne Microorganisms. The ACGIH⁵ recommends a pre-assessment of the extent of microbial contamination prior to initiation of air sampling. Airborne microbials sampling equipment is available from the HRT if sampling is necessary.
   
   Before biological sampling, several precautions must be taken including making arrangements for preparing culture media for sampling, specialized shipping procedures, and making arrangements for analysis by a laboratory familiar with the handling and processing of biological samples. Contact the Directorate of Technical Support for information about laboratories experienced in the analysis of microbial samples and with knowledge of the health effects.
   
   Legionella pneumophila is often present in hot water tanks, washing systems, and pools of stagnant water, but health effects are not observed until the contaminants become aerosolized within the building confinements.
   
   The identification of predominant taxa, or at least fungi, is recommended in addition to determining the number of colony-forming units/m³ of air (cfu/m³). During growing seasons, outdoor fungus-spore levels can range from 1,000 to 100,000 cfu/m³ of air.
   
   Contamination indicators:⁹
   Levels in excess of the above do not necessarily imply that the conditions are unsafe or hazardous. The type and concentrations of the airborne microorganisms will determine the hazard to employees.
   • 1,000 viable colony-forming units in a cubic meter of air
   • 1,000,000 fungi per gram of dust or material
   • 100,000 bacteria or fungi per milliliter of stagnant water or slime

 

Seems like almost all of the journal articles for IQA in food (there are a lot of them for flour mills, breweries, etc) cite this guy - http://ibe.sagepub.c...17/2/155.short - but I don't have a subscription or access to the entire PDF.

[Charles.C]

Dear srose,

 

AFAIK, there are no global standards for TPC/Y&M in food manufacturing environments.

Suggested TPC standards are typically based on methods using either (a) impaction or (b) sedimentation, eg settle plates. A lot of the food-related development came via milk industry. A lot of the terminology is via cleanroom applications like Pharmaceutical manufacturing, aseptic food processing/packaging

 

For settle plates, suggested limits are usually quoted in units of viable particles/plate area/exposure time.

One set of  TPC air data standards due to APHA (Compendium of methods for the microbiological examination of food,2001) gives  values for settle plates of  12,900/64,600/323,000 Avg.no.viable particles/metre2/week for NASA classes 100/10,000/100,000 respectively. The class selected depends on the (risk) application, eg aseptic area /  external areas to aseptic environment, etc.

Limits for Yeast and Mould are AFAIK intuitive, based primarily on observed measurements.

For TPC and Y&M, see sheet Sh1 in the excel document in this link –

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

The APHA value mentioned in above link is similar to the settle plate value quoted above for class 100,000.

 

Rgds / Charles.C

 

PS - the 15min exposure you mentioned is a commonly used (arbitrary) time but other durations are also used. It depends. But as to the mysterious 500/cfu (unit ??) only hygienic (may) know the  answer.

[Vinit]

Happy New Year to all IFSQN members.

 

Does anyone know the reference for the standard '500 /cfu for both TPC and Y/M exposure time 15 minutes' provided by hygenic in the post above? I know the post is a bit dated but I am searching for a Y&M standard for indoor air quality in a food processing facility that has a wet process.

 

Thanks

 

Dear srose,

 

AFAIK, there are no global standards for TPC/Y&M in food manufacturing environments.

Suggested TPC standards are typically based on methods using either (a) impaction or (b) sedimentation, eg settle plates. A lot of the food-related development came via milk industry. A lot of the terminology is via cleanroom applications like Pharmaceutical manufacturing, aseptic food processing/packaging

 

For settle plates, suggested limits are usually quoted in units of viable particles/plate area/exposure time.

One set of  TPC air data standards due to APHA (Compendium of methods for the microbiological examination of food,2001) gives  values for settle plates of  12,900/64,600/323,000 Avg.no.viable particles/metre2/week for NASA classes 100/10,000/100,000 respectively. The class selected depends on the (risk) application, eg aseptic area /  external areas to aseptic environment, etc.

Limits for Yeast and Mould are AFAIK intuitive, based primarily on observed measurements.

For TPC and Y&M, see sheet Sh1 in the excel document in this link –

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

The APHA value mentioned in above link is similar to the settle plate value quoted above for class 100,000.

 

Rgds / Charles.C

 

PS - the 15min exposure you mentioned is a commonly used (arbitrary) time but other durations are also used. It depends. But as to the mysterious 500/cfu (unit ??) only hygienic (may) know the  answer.

 

Hi..

 

Work area, level table with ample surface in room that is clean, well-lighted (100 foot-candles at working surface) and well-ventilated, and reasonably free of dust and drafts. The microbial density of air in working area, measured in fallout pour plates taken during plating, should not exceed 15 colonies/plate during 15 min exposure.

 

Pls see the below link by FDA

 

http://www.fda.gov/F...s/ucm063346.htm

[Charles.C]

 

Hi..

 

Work area, level table with ample surface in room that is clean, well-lighted (100 foot-candles at working surface) and well-ventilated, and reasonably free of dust and drafts. The microbial density of air in working area, measured in fallout pour plates taken during plating, should not exceed 15 colonies/plate during 15 min exposure.

 

Pls see the below link by FDA

 

http://www.fda.gov/F...s/ucm063346.htm

 

 

Hi Vinit,

 

Thks for the post but I'm a little puzzled by yr link which seems to be a plate count procedure for foods and cosmetics ?.

 

Yr quoted limit of 15cfu/plate/15min is interesting, Can you inform the source?

 

Assuming a 9cm diameter plate, value above calculates to ca.160 cfu./cm2/week as compared to APHA's recommended level of 30. However  the source paper of excel sheet1 link shows that measured values varied in range 10-95 depending on product/sampling location, ie probably need to establish baselines.

.

[biosyn]

I am also confused and would like to see a worked set of examples for the Omeliansky formula examples.  Petri plates are 9cm in diameter, Settling plate method is used to collect samples exposed to the air for 45minutes, Visual inspection to count colonies (raw count). Please show sample formula workings used to complete the table.

 

1.

SAMPLE

ACTUAL RAW COUNT IN A 9CM DIAMETER PETRI PLATE SAMPLED FOR 45MINUTES

CFU/M³

2.

Outdoor Control #1

20

 

3.

TV/Sunroom

10

 

4.

Kitchen

14

 

5.

Pantry

2

 

6.

Laundry

36

 

7.

Lounge

9

 

[Charles.C]

Hi biosyn,

 

Is this yr homework ?

 

Omeliansky’s formula:

 

N=5a x 10^4 /(bt)

 

where N is CFU/m3 ,

 a is the number of colonies per Petri dish for the time t,

 b is the Petri dish surface area (cm2 ),

 t  is  the  exposure  time  (min).

 

With yr data (radius 4.5cm / 45min) the formula gives –

 

N = 17.5a (cfu/m3)

 

Yr data for “a”  is 20, 10, 14, 2, 36, 9

 

So  N = 350, 35, 245, 35, 630, 157.5

 

(The last one should perhaps be "rounded" down )

[_Ryan_]

Dear srose,

 

AFAIK, there are no global standards for TPC/Y&M in food manufacturing environments.

Suggested TPC standards are typically based on methods using either (a) impaction or (b) sedimentation, eg settle plates. A lot of the food-related development came via milk industry. A lot of the terminology is via cleanroom applications like Pharmaceutical manufacturing, aseptic food processing/packaging

 

For settle plates, suggested limits are usually quoted in units of viable particles/plate area/exposure time.

One set of  TPC air data standards due to APHA (Compendium of methods for the microbiological examination of food,2001) gives  values for settle plates of  12,900/64,600/323,000 Avg.no.viable particles/metre2/week for NASA classes 100/10,000/100,000 respectively. The class selected depends on the (risk) application, eg aseptic area /  external areas to aseptic environment, etc.

Limits for Yeast and Mould are AFAIK intuitive, based primarily on observed measurements.

For TPC and Y&M, see sheet Sh1 in the excel document in this link –

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

The APHA value mentioned in above link is similar to the settle plate value quoted above for class 100,000.

 

Rgds / Charles.C

 

PS - the 15min exposure you mentioned is a commonly used (arbitrary) time but other durations are also used. It depends. But as to the mysterious 500/cfu (unit ??) only hygienic (may) know the  answer.

If I have 25 CFU on 90mm plate with an hour exposure time, how do I should express final report with regarding to 30 CFU. cm-2. week-1 maximum acceptable level  (APHA standards)?

[Raj123]

Hai everyone

 

 

What are the standards for total count for settle plate method if we carried out at un classified area or storage area?

[Eranga Thilina Jayashantha]

If I have 25 CFU on 90mm plate with an hour exposure time, how do I should express final report with regarding to 30 CFU. cm-2. week-1 maximum acceptable level  (APHA standards)?

 you can calculate as below;

 

25 cfu/(64 cm2)*24 h * 7 days = 66 cfu/cm2/week