Grade "A" Pasteurized Milk Ordinance (2003
Revision)
Appendices E through G
Appendix E. Examples of 3-out-of-5 Compliance Enforcement Procedures
The
following Tables provide several useful examples in the application of the enforcement
system described in Section 6. While the illustrations given, relate only to
pasteurized milk bacterial counts and somatic cell counts of raw milk, the method
is applied, in like fashion, to the enforcement of established standards for
cooling temperature, coliform limits, etc. Pasteurized milk or milk product that
shows a positive phosphatase reaction and milk or milk product, in which the
presence of drug residue, pesticides or other adulterants is found, shall be
dealt with as indicated in Sections 2 and 6, respectively.
Table 11. Example of Enforcement Procedures for Pasteurized Milk Laboratory Examinations
Date |
Bacterial Count per mL |
Enforcement Action as Applied to a Standard of 20,000/mL |
1/05/03 |
6,000 |
No Action Required |
1/28/03 |
11,000 |
No Action Required |
2/11/03 |
12,000 |
No Action Required |
3/15/03 |
22,000 |
Violative; No Action
Required |
3/25/03 |
23,000 |
Violative; Written notice
to plant, 2 of last 4 counts exceed the standard. (This notice shall be in effect as long as 2 of the last 4 consecutive
samples exceed the standard). Additional
sample required within 21 days from the date of the notice, but not before
the lapse of three (3) days. |
4/02/03 |
9,000 |
No Action Required |
4/19/03 |
51,000 |
Violative (3 of last 5 counts exceed the standard); Required Regulatory Actions:
- Suspend plant permit; or
- Forego permit suspension, provided the milk or milk product(s) in violation
are not sold as Grade "A" product(s); or
- Impose monetary penalty in
lieu of permit suspension, provided the milk or milk product(s) in violation
are not sold as Grade "A" milk or milk product(s).
|
4/23/03 |
|
Issue temporary permit (if applicable) after plant inspection. Begin accelerated sampling schedule. |
4/25/03 |
11,000 |
No Action Required |
4/29/03 |
3,000 |
No Action Required |
5/4/03 |
22,000 |
Violative; No Action Required
NOTE: Samples collected prior to 4/23/03 are not used for subsequent
bacterial count enforcement purposes. |
5/9/03 |
5,000 |
Permit Fully Reinstated |
Table 12. Example of Enforcement Procedures for Raw Milk Laboratory Examinations
Date |
Confirmed Somatic Cell Counts per mL |
Enforcement Action as Applied to a Standard of 750,000 per mL |
7/10/03 |
500,000 |
No Action Required |
8/15/03 |
600,000 |
No Action Required |
10/1/03 |
800,000 |
Violative; No Action Required |
11/7/03 |
900,000 |
Violative; Written notice to producer, 2 of last 4
counts exceed the standard. (This
notice shall be in effect as long as 2 of the last 4 consecutive samples
exceed the standard). Additional
sample required within 21 days from the date of the notice, but not before
the lapse of three (3) days. |
11/14/03 |
1,200,000 |
Violative (3 of last 5 counts exceed the standard);
Required Regulatory Actions:
- Suspend producer permit; or
- Forego permit suspension, provided the milk in violation is not sold as Grade
"A"; or
- Impose monetary penalty in lieu of permit suspension, provided
the milk in violation is not sold or offered for sale as Grade "A " product. Except that
a milk producer may be assessed a monetary penalty in lieu of permit suspension
for violative counts provided: If the monetary penalty is due to a violation
of the somatic cell count standard, the Regulatory Agency shall verify that the
milk supply is within acceptable limits as prescribed in Section 7 of this Ordinance.
Samples shall then be taken at the rate of not more than two (2) per week on
separate days within a three (3) week period in order to determine compliance
with the appropriate standard as determined in accordance with Section 6 of this
Ordinance. (Refer to Section 3)
|
11/18/03 |
700,000 |
Issue temporary permit (if applicable) after
sampling indicates the milk is within the standards prescribed in Section 7.
Begin accelerated sampling schedule. |
11/20/03 |
800,000 |
Violative; No Action Required
NOTE: Samples collected prior to 11/18/03 are not used for subsequent somatic cell count enforcement purposes. |
11/24/03 |
700,000 |
No Action Required |
11/29/03 |
550,000 |
Permit Fully Reinstated |
Appendix F. Sanitization
I. METHODS OF SANITIZATION
CHEMICAL
Certain chemical
compounds are effective for the sanitization of milk containers, utensils and
equipment. These are contained in 21 CFR 178.1010 and shall be used in accordance
with label directions.
STEAM
When steam is used, each group of assembled
piping shall be treated separately by inserting the steam hose into the inlet
and maintaining steam flow from the outlet for at least five (5) minutes
after the temperature of the drainage at the outlet has reached 94°C (200°F).
The period of exposure required here is longer than that required for individual
cans, because of the heat lost through the large surface exposed to the air.
Covers must be in place during treatment.
HOT WATER
Hot water may be
used by pumping it through the inlet, if the temperature at the outlet
end of the assembly is maintained to at least 77°C (170°F) for at
least five (5) minutes.
II. EVAPORATING, DRYING AND DRY PRODUCT EQUIPMENT CLEANING
CLEANING
- Cleaning or Evaporators and Condensers: Some evaporators are designed
so that the milk or milk product is exposed to large surface areas for a long
period
of time at temperatures conducive to the growth of microorganisms.
Pipelines and/or equipment designed for automated mechanical cleaning of evaporators
should meet the following requirements:
- A pH recording device should
be installed in the return solution line to record the pH and time, which
the line or equipment is exposed during the cleaning and sanitizing operation.
- These pH recording charts should be identified, dated, and retained for
three (3) months.
- During each official inspection the Regulatory
Agency should examine and initial the pH recording charts to verify the
time of exposure to the cleaning solutions and their pH.
The following are suggested procedures for cleaning and sanitizing evaporators and condensers:
The surface area inside an evaporator is extremely large. Not only is there
a large separator chamber and vapor lines but steam chests may also have
as many as 500 to 1400 heating tubes from three (3) to fifteen (15) meters (ten (10)
to fifty (50) feet) long. The total surface area may be 4,000 to 35,000
square feet, which may require large volumes for recirculation. This surface area
must be cleaned and sanitized carefully or it will contaminate the milk
or milk product. The operating temperatures in an evaporator are very close
to the growing temperatures of thermoduric and certain mesophilic types of
bacteria. The first effect may operate at 60°C (140°F) to 77°C (170°F),
the second effect at 52°C (125°F) to 63°C (145°F), and the third effect at 38°C (100°F) to
49°C (120°F). The product being evaporated is often recirculated in the
last effect several times until the right concentration is reached, which may give
bacteria ample time to grow. A clean evaporator operates more efficiently.
It is necessary to clean the evaporators after long periods of operations because burned-on
material reduces heat transfer and efficiency. A point is reached where
it will be more economical to stop and clean up than to continue to operate.
Evaporators need cleaning for sanitary reasons as well as for efficient operation.
Tube chests and heating plates must be cleaned to get good heat transfer.
If vapor lines are not cleaned, it is possible to get a back surge of vapor when
the vacuum is released. This can carry soil back into the milk or milk
product thus lowering the quality. This soil may drop into the thermo-compression
unit, block passage of vapors and actually prevent good operation. Compounds
for cleaning are usually divided into two (2) main groups:
- The alkaline cleaners usually contain caustic with water conditioners, synthetic
detergents and foam depressants added to enhance cleaning action. The purpose
of the alkaline cleaner is to digest the bulk of the soil. The alkaline
solutions are usually run first at concentrations ranging from one percent (1%) to
three percent (3%) at temperatures of 83°C (180°F) to 88°C (190°F) for
thirty (30) to sixty (60) minutes.
- Acid cleaners are usually food grade with synthetic
detergents and inhibitors to prevent attack on metal surfaces. The purpose
of acid cleaners is to remove mineral films, alkali cleaner residues, and
shine the inside surfaces. Acid solutions are usually used last at concentrations
of 0.2
percent (0.2%) to 0.5 percent (0.5%) at 60°C (140°F) to 71°C (160°F).
In all cases cleaners and cleaning instructions should be followed as recommended by
the manufacturer of the cleaning compound. It is also necessary to follow
the recommendations and instructions of evaporator manufacturers. The evaporators operating
with compressed ammonia require special cleaning precautions.
Cleaning Methods: There are three (3) basic methods of cleaning evaporators:
- Boil-out;
- Circulation;
- Spray cleaning; or
- A combination of the three methods.
- The boil-out method is the oldest, but
it is still very effective. It is accomplished by rolling or boiling the
cleaning solution under partial vacuum. Heat is applied by the evaporator
and just enough vacuum is used to roll the solution. Cleaning solutions
are elevated
to the dome and upper parts by opening and closing the vacuum breaker.
Hand-brushing of some areas is often necessary following boil-out because
it is difficult
to thoroughly clean the upper surfaces with this method.
- Circulation cleaning is a newer method of cleaning. The cleaning solution
actually follows the milk or milk product path. The solution is circulated
by returning
it back to the starting point. Heat is applied by a pre-heater, tube chest,
or steam jet, sometimes called a boil-out nozzle. This method is not adaptable
to all types of evaporators and it is usually necessary to add spray cleaning
devices to thoroughly clean separators and the bottom tube sheet in steam
chests.
- Spray cleaning is the newest method of cleaning evaporators. Cleaning
solutions are pumped through spray devices and distributed over the surfaces,
which
are contacted by the milk or milk product. Heat is applied by a pre-heater,
a surge tank, or on the run with live steam. When properly designed and
operated spray cleaning systems are used, cleaning problems are at a minimum.
Spray
cleaning offers many advantages over boil-out or circulation methods of
cleaning. Less water and less cleaning solution is required. This not only
results
in a saving of water, heat and cleaners, but more concentrated cleaning
solutions can be used giving faster, more effective cleaning. Heat for the
rinse water
and cleaning solutions is applied externally, preventing additional burn-on
in tube chests. As the evaporator is not under vacuum, less heat is required
to
keep the solution hot, resulting in a saving of fuel. Higher temperatures
can be used to improve cleaning efficiency. There are some disadvantages
to spray cleaning.
Spray devices cost extra money because they are specifically designed for
almost every operation. Spray devices must be properly placed and designed
to
cover the top of the dome in the separator, the tangential inlets, the
vapor lines, sight glasses, and steam chest tubes. Spray cleaning may require
additional stainless steel lines to convey the solution at the necessary
volumes.
Larger pumps are also required to pump the necessary volume of cleaning
solution. Even with these disadvantages, the advantages of savings in heat,
water, cleaning compound and time outweigh the disadvantages.
- Sometimes there are advantages in using combined systems of cleaning.
It may be possible to boil-out the steam chests and spray the separators.
Sometimes it is possible to circulate
the steam chests and spray clean the separators or other portions of the
unit. Quite often the combined systems, especially the circulation in the
spray system, will work best on certain types of evaporators.
- One of the biggest factors affecting the method of cleaning used is the
type of evaporator. In a falling film type evaporator, circulation cleaning
can be used to clean the tube chests and spray cleaning can be utilized
to clean the
evaporator chambers. When using a plate-type evaporator, circulation cleaning
is best. In an internal type tube chest, a boil-out system for the tubes
and spray cleaning
of the separator works very well. With an external chest type evaporator,
the entire unit can be spray cleaned. If it is a compressed ammonia operated
evaporator,
spray cleaning works well. Sanitizing should be done to eliminate any microorganisms,
which may have survived the cleaning regimen. Sanitizing can best be accomplished
by using chemical sanitizers. Heat may be used if all surfaces are heated
to 83°C (180°F) or higher. Since there is a tremendous investment in stainless
steel evaporators, it is necessary to use cleaning and sanitizing products,
which do not corrode stainless steel. Chemical sanitizers can be applied
through the spray equipment or they can be applied with fogging guns.
- High-Pressure Pump and High-Pressure Lines: The high-pressure pump and
high-pressure line to the dryer nozzles may be cleaned as a separate circuit by connecting
the line to the nozzle back to the drop tank and this tank connecting to
the inlet of the high-pressure pump. The regular milk or milk product atomizing nozzles
should be removed before cleaning is to be done.
Another method of cleaning the high-pressure pump and lines is to include this pump and high-
pressure lines in the circuit when wet cleaning some types of spray dryers. In either
case a solution of one to three percent (1-3%) caustic heated to 72°C (160°F)
should be circulated for at least thirty (30) minutes. A solution of inhibited
acid should be pumped through the atomizing system as a daily procedure
to remove the milkstone from the high-pressure pump and high-pressure line.
A solution of inhibited acid should be recirculated a minimum of ten (10)
to fifteen (15) minutes and followed by a rinse with potable water.
It is also recommended that the high-pressure pump head be disassembled
as a daily procedure immediately following the final rinse and the parts
be placed
on a table or rack for air drying. When the pump is disassembled the parts
are to be checked to see if they are clean, and to see if any maintenance
is required to remove pits. Seats are also checked at this time. Since
a high-
pressure pump is subjected daily to extreme heavy duty, the valves and
seats are recommended to be ground periodically to maintain uniform pressure
on the
atomizing nozzles. Prior to use, the entire system should be sanitized.
- Wet Cleaning of Dryers: There are several methods of wet cleaning dryers:
- The first method is hand-brushing. The cleaning personnel go into the
dryer with buckets of cleaning solution and brush all surfaces of the
dryer. The unit is then rinsed with a hose.
- Cleaning can also be done with hand-operated
spray guns . These spray guns are pressure pumps, which operate at high
pressures in low volumes. In many cases, box-type dryers can be completely
cleaned with the addition of a seven (7)-foot extension on these pressure
guns.
By using high-pressure spray guns and cleaning compounds with a high synthetic
detergent content, it is possible to remove very difficult soil.
- The third method of wet cleaning is by spray cleaning with various types
of stationary or rotating spray devices. They usually operate at a high
volume of low pressure
in the range of 69 kPa (10 psi) to 138 kPa (20 psi). Constant spray coverage
can be obtained when spray devices are properly designed. Usually several
spray
devices are required because of the many chambers, collectors, and down
pipes within these units. Less time is required to do a complete job with
spray cleaning.
The systems are installed so that cleaning lines are easily connected to
the spray devices and an effective return system. Spray cleaning time is
much shorter than hand cleaning time, especially in large units. Spray
cleaning eliminates the entry of cleaning personnel into the drying units.
Silo or vertical
type dryers are often 6.2 meters (20 ft.) to 30.4 meters (100 ft.) high
and it is difficult and dangerous to clean by hand or by hand operated
units. Spray cleaning eliminates the flavor contamination when switching
to other milk or milk
products. If an ungraded milk or milk product is run through the dryer,
it is necessary to thoroughly clean before running a Grade "A " milk or milk
product. There are disadvantages to spray cleaning. The spray devices must
be properly placed and designed to do the complete cleaning job. They must be removable so
as not to affect the air currents during operation. However, the advantages
of safety plus cleaning time and consistently complete cleaning outweigh
the disadvantages. A typical spray cleaning cycle might operate as follows:
- (1) The various spray heads are placed in the dryer and securely fastened into
place. The rinse water is pumped through the spray device and allowed to run down the side-walls
of the drying units. Cleaning compounds which are mild alkaline or chlorinated
cleaners are prepared at 0.3 to 1 percent (0.3-1%)concentration, heated
to 71°C (160°F) to 83°C (180°F), and circulated for forty-five (45) minutes
to one (1) hour. The unit is given a final rinse and is thoroughly dried.
Occasionally acid type cleaners are used to control mineral films. Sanitizing
with chemical sanitizers is a controversial subject. Sanitizing can be done with heat
but it may be difficult to heat all surfaces to 83°C (180°F). Heating to
83°F (180°F) for ten (10) minutes does not kill spore formers. However, they are killed
with many chemical sanitizers. Even if heat is used, it is recommended
that chemical sanitizers be occasionally used. By pumping the sanitizer
solution to the high-pressure pump or by fogging with high pressure, it is possible
to completely cover the milk or milk product-contact surface. Actually,
the unit must be thoroughly dried before operation. Chlorine sanitizers
may cause corrosion. Obviously, these compounds should be used with care. If chlorine
is left on the dryer and heat is applied, the chlorine droplets will become
hot and concentrate and cause pitting. When chlorinated cleaners are used,
a dryer surface can be effectively cleaned and at least partially sanitized
and the solution can be completely rinsed. Acid-synthetic detergent type
sanitizers have been developed, which are effective on spore formers. These
compounds are germicidal, effective in hard water and stable in hot or cold solutions.
They have an advantage in that they are noncorrosive to dairy metal.
- (2) It is not necessary to wet clean dryers on a daily basis. However, a schedule
should be set up so cleaning is done periodically. As long as a dryer is
operating continuously, it is not necessary to clean it from an efficiency
standpoint. Some types of dryers require very little cleaning, maybe once each month;
others require dry cleaning on a more frequent basis. It is necessary to
clean and sanitize dryers if they are going to remain idle any appreciable length
of time. Bacteria may grow in dryers, which remain idle. Dryers must be
spray cleaned if they are improperly operated, causing burn-on in the drying
chamber. Whenever fires develop inside the drying unit or when burn-on
occurs, it is necessary to thoroughly clean at least the drying chambers. Quality is
the key to the dry milk industry. There should be a program of cleaning
and sanitizing of both evaporators and dryers. Better quality milk and milk products are
produced in evaporators and dryers when thoroughly cleaned and sanitized
on a regular basis.
- Dry Cleaning: It is very difficult to discuss proper
cleaning procedures without also discussing proper operating procedures,
especially
the start-up and shutdown of the dryer. Assuming the dryer has been properly
started and operated throughout the run or drying cycle, the first step
in a successful cleaning operation is shutting the dryer down properly.
The type
of energy supplying heat to the dryer chamber, i.e., steam or gas, alters
the proper shutdown technique. The correct procedure in shutting down a
steam heated dryer is as follows:
- Shut off the main steam valve at the proper time.
- Maintain the proper dryer outlet temperature for drying by gradually reducing
the output of the high-pressure pump until the residual heat of the steam
coil is dissipated to a point where it does not maintain proper temperature
or until the milk or milk product being pumped by the high-pressure pump
does not maintain a satisfactory spray pattern.
- Keep the dry milk product
removal system and conveying system in operation.
- Keep the air intake
and exhaust fans on the dryer in operation until the main chamber is sufficiently
cooled to provide a comfortable atmosphere for the cleaning personnel.
On a gas-fired spray dryer, the burner assembly has very little or no residual
heat capacity. Therefore, the shutdown is more rapid. The correct procedure
for shutting down a gas-fired dryer is as follows:
- Shut off the gas supply to the burner.
- Immediately shut off the high-pressure pump.
- Same procedure as steam heated dryer.
- After the above procedures have
been accomplished, shut down the intake fan. Let the exhaust fan and vibrators
or
shakers continue to operate, along with the milk and milk product removal
system. The exhaust fan should be severely dampered so that it induces
only a small
air-flow. A small auxiliary fan is sometimes used in lieu of the dampered
exhaust fan. The use of either fan serves a twofold purpose: First, it
is helpful to
put the drying system under a slight negative pressure to reduce the tendency
for milk or milk product to drift out of the system into the milk plant
through open doors, etc. Secondly, it is vital to prevent thermal currents
from creating a reverse air-flow through the drying system, which tends to deposit milk
or milk product on the heating surfaces and plenum duct. Milk or milk product
deposits on steam coils reduce their heating ability, create sediment and
conceivably bacterial problem areas. If the dryer is gas fired, there is a further
hazard of fire. It is important; therefore, that the closure or covers
supplied by the manufacturer be placed on the inlet air duct system simultaneous with
the shutdown of the fan. After any prime milk or milk product has been
removed from the drying system, the system is ready for cleaning. The cleaning
personnel should be supplied each day with a freshly laundered set of coveralls,
white
cap, white face mask, and clean rubbers or boot covers (canvas or single-service
plastic). Prior to donning the above uniform, the procedure is to remove
the spray nozzles and pipes as these are normally cleaned with the liquid
dryer feed equipment. With clean uniforms, proper brushes and preferably vacuum
cleaning equipment, the cleaning personnel enter the main dessicator chamber
and start the cleaning process as far upstream as possible from the milk or milk
product removal or pneumatic conveyor system:
- (1) The first portion
cleaned is the collector system. This is done by inserting a brush into
the cloth tubes
and brushing the length of the tube. Again, this can be done more satisfactorily
by utilizing the special vacuum tools designed and available for this service.
- (2) Remove the dust covers and brush or vacuum out the nozzle ports.
- (3) Manually brush or vacuum the ceiling and walls of the drying chamber.
- (4)
Sweep or vacuum clean the floor of the dryer, placing milk or milk product
in a container.
NOTE:
Do not remove this milk or milk product by way of the milk and milk product
removal system.
- (5) Inspect the dryer for any inadvertent wet spraying
or nozzle drippings that may have occurred during the drying cycle. Should
either of these have occurred, the application of a minimum amount of water
and effort will be required to remove the clinging material. Any moisture
introduced must be removed before operation begins because of its effect
upon smooth milk
or milk product flow and because it would establish a more favorable environment
for bacterial growth if it were allowed to remain.
- (6) Check the collector
for loose or torn bags and any other mechanical checks necessary before
leaving the dryer.
- (7) Close the dryer securely and check the switches
to make sure they are in the proper starting positions. At frequent intervals,
not
over a two (2) week period, the operator should clean and inspect the heated
air intakes of the dryer, assuming that the dryer is properly operated
during this time. However, should a malfunction occur where the dryer operator
does
not follow the procedures outlined for proper shutdown, it may require
an inspection and cleaning at closer intervals. Frequent inspection will
eliminate a source of sediment contamination.
- (8) On start up after dry cleaning of the
cloth collector dryer, the first two (2) bags of milk or milk product shall
be discarded.
This will allow for the removal of any milk or milk product remaining in
the tubes and system after shutdown.
AUXILIARY DRY PRODUCT EQUIPMENT
- Sifters: In general, there are two (2)types of dry product sifters in use
by the dry milk industry. These are the shaker type and the rotary or gyrating
type. Both are designed to operate at various capacities either manually
bagging or packaging from their outlet or designed for automatic packaging equipment.
For the general guidance of sifter manufacturers and the dry milk industry,
the following screen size openings may be considered as recommended openings
to result in satisfactory screening of the listed dry milk product:
Table 13. SIEVE SIZES AND DESIGNATIONS
PRODUCT |
SIEVE DESIGNATION 223.1 |
MAXIMUM SIEVE OPENING (APPROS) |
mm |
inch |
Nonfat dry milk |
#25 |
0.707 |
0.027 |
Dry whole and dry buttermilk |
#16 |
1.19 |
0.047 |
It is recognized that larger
screen size openings may be necessary for sifting certain special dry milk
products, such as "instant" products, and for classification
of dry milk products into different particle sizes.
Openings referred
to above are based on general experience as to what constitutes satisfactory
screening
to remove dry milk product lumps or potential dry milk product contamination,
and also on the ability of most currently used sifters to successfully
sift
dry milk products through such size openings, without excessive loss of
fine dry milk product into the "reject material" outlet. Other
factors also affect loss, such as:
- Percent of "open area" in
the screen used;
- Uneven flow rates to the sifter;
- Ratio of screening surface to dryer capacity;
- Amount and kind of mechanical
energy applied to the screening surface;
- Sifter design and construction;
and
- Nature of dry product being sifted.
Screen opening dimensions may
be obtained by any desired combination of wire thickness and number of
wires per
inch. For instance, if the screening surface is made of stainless steel
woven wire, the 0.707 mm (0.027 inch) opening might be obtained by using
24 X 24
mesh market grade screen cloth made of wire 0.399 mm (0.014 inch) thick
(about 45 percent (45%) open area) or by using 30 X 30 bolting cloth screen
made of
wire 0.185 mm (0.0065 inch) (about 65 percent (65%) open area) or by many
other mesh-wire thickness combinations. These combinations allow a wide
choice to
obtain a desired balance between screen strength and percent open area.
If materials other than stainless steel are used to construct the screening
surface,
similar combinations may be employed to achieve the desired opening size.
Recommendations for Cleaning Dry Milk Product Sifters:
- Dry Cleaning Program:
The procedures set forth below should be followed:
- (1) Completely dismantle
and thoroughly vacuum or dry brush-clean all dry milk or milk product-contact
surfaces of the dry milk sifter. Reassemble as soon as finished and make
every effort to keep all parts dry.
- (2) Check the sifter screen(s) for broken or displaced wires (threads) and for other openings around the
frame of the screen, which might permit the passage of un-sifted dry milk product. Other
parts of the sifter, including ball trays and balls, if used, should also
be inspected for condition. Any necessary repair or replacement should
be made
as soon as possible.
- (3) Flexible rubber or cloth connectors at the
inlet and outlets of the sifter should be thoroughly cleaned daily following
the procedures as recommended for the sifter. At this time, connectors should
be closely examined for holes, cracks, or other damage.
NOTE: To
facilitate removal for cleaning, the use of easily removable, fastening
devices are recommended.
- (4) Thoroughly vacuum or dry brush-clean all external parts of the sifter,
including the sifter frame and drive mechanism.
- Wet Cleaning
Program: The procedures set forth below should be followed:
- (1) Completely dismantle
as cited in a.(1) above; remove all loose dry milk product; then rinse
all parts with clear
water; and follow by a thorough hand-brushing of all parts, using a general
purpose dairy cleaner. Rinse thoroughly to remove all evidence of cleaning
solution or soil. It is recommended that hot water at 77°C (170°F) or above
be used for rinsing in order to sanitize the equipment and to aid the subsequent
drying.
- (2) Allow all parts to air dry completely prior to reassembly.
- (3) The wet wash should be done as frequently as necessary and should be done
after each use, if the sifter is not being used on a daily basis.
- (4) After cleaning, drying and reassembly, the dry milk product outlet should
be protected from contamination.
- General Recommendations:
- (1) Vacuum cleaning
is preferred to brush-cleaning or cleaning with air under pressure as it
decreases
the dust drift problem to other areas of the milk plant.
- (2) Brushes
or vacuum cleaner fittings, used for cleaning dry milk product-contact
surfaces,
should not be used for cleaning non-dry milk product-contact surfaces or
for other uses, which might result in contamination. Such brushes and special
fitting
should be stored in an enclosed cabinet when not in use. For protection
and housekeeping considerations, such cabinets preferably should be of
non-wood
construction and should have open mesh metal shelving.
NOTE: For
additional details refer to 3-A Sanitary Standards for Sifters for Dry
Milk and Dry Milk
Products, Serial 26-.
- Storage/Shipping Bins: The use of portable
bins, totes, super sacks, or other portable storage/shipping containers
shall comply with the construction requirements of Item 11p and the cleaning
and sanitizing requirements of Item 12p of this Ordinance.
If interior bracing and ladders are used in milk plant storage bins, they shall be
constructed f smooth rounded metal, and be installed sufficiently far from the walls
to prevent harborages. Dry milk product entrance and discharge openings
connected to the attending conveying equipment shall be dust-tight and shall be easily
accessible for cleaning. Vents to the exterior shall be equipped with readily
removable air filters of adequate capacity or readily removable covers.
If air is to be introduced into the dry milk product zone, only filtered
air shall be used, and it shall comply with the applicable standards of Appendix
H. Auxiliary agitators or any other interior devices, if used, shall be
designed to be smooth, crevice-free, and readily cleanable. The exterior surface of the bin should
be smooth, hard finished, and readily cleanable. Hinges on covers, if used,
shall be the take-apart type. Covers or doors shall be provided to enclose
the dry milk product zone when dry milk product is not being dumped. These
shall be so constructed that dirt or dust on the top will not slide or
fall into the bin when the cover is open. Access openings shall be provided
on all in-milk plant bins. Such openings should not be less than 45.7 centimeters
(18 inches) in its smallest dimension. Covers shall be constructed without
raised internal reinforcements and should be hinged and equipped with a
quick opening device. The gaskets for such openings shall be made of solid
material that is non-toxic, nonabsorbent, smooth, and unaffected by the dry milk
product. Storage/shipping bins in continuous use either in the milk plant
or in transporting dry milk products from one (1) milk plant to another should be cleaned
according to manufacturer's recommendations when necessary. They may be
cleaned by either approved dry cleaning methods or wet cleaned.
- Packaging and Packages: Packaging equipment for dry milk products will vary greatly as
to their design depending upon whether the packages being filled are drums, bins or bags.
Whatever equipment is used, it should be designed so as to protect the
dry milk product from contamination from outside sources and from air during the packaging
operation. All connections of conveying equipment to packaging devices
should have dust-tight connections. All conveyors, ducts, belts and screws used in connection
with packaging equipment should be provided with a dust collector system,
capable of eliminating any visible dust. All dry milk product hoppers, when used,
should be provided with covers to properly protect the dry milk product
from contamination. Hand-filling should not be permitted except for periods of adjustment of
automatic weighing devices.
Appendix G. Chemical and Bacteriological Tests
I. PRIVATE WATER SUPPLIES AND RECIRCULATED WATER- BACTERIOLOGICAL
Reference: Section 7, Items 8r, 19r, 7p and 17p.
Application: To private water supplies,
used by dairy farms, milk plants, receiving stations, transfer stations and
milk tank truck cleaning facilities, and to recirculated cooling water, used
in milk plants, receiving stations and dairy farms.
Frequency: Initially; after repair, modification or disinfection of the private water supplies
of dairy farms, milk plants, receiving stations, transfer stations and
milk tank truck cleaning facilities, and thereafter; semiannually for all milk plants,
receiving stations, transfer stations and milk tank truck cleaning facilities
water supplies and at least every three (3) years on dairy farms. Recirculated
cooling water in milk plants, receiving stations and on dairy farms shall
be tested semiannually.
Criteria: A Most Probable Number (MPN) of coliform
organisms of less than 1.1 per 100 mL, when ten (10) replicate tubes containing
10 mL, or when five (5) replicate tubes containing 20 mL are tested using
the multiple tube fermentation technique, or less than 1 per 100 mL by
the membrane filter technique, or less than 1.1 per 100 mL when using an MMO-MUG technique.
(The MMO-MUG technique is not acceptable for recirculated cooling water).
100 ± 2.5 ml water will be used for this analysis. Any sample producing a bacteriological
result of Too Numerous To Count (TNTC) - greater than two hundred (200)
total bacteriological colonies per 100 mL by the membrane filter technique;
or confluent growth by the multiple tube fermentation, MPN technique, without
coliform present, shall have a subsequent heterotrophic plate count of less than five hundred
(500) colonies per mL in order to be deemed satisfactory. Findings shall
be reported as present or less than 1 per 100 mL, absent for coliform organisms.
Apparatus, Method, and Procedure: Tests performed shall conform with the current edition
of SMEWW or with FDA approved, EPA promulgated methods for the examination
of water and waste water.
Corrective Action: When the laboratory report
on the sample is unsatisfactory, the water supply in question shall again
be physically inspected and necessary corrections made until subsequent
samples are bacteriologically satisfactory.
II. PATEURIZATION EFFICIENCY - FIELD PHOSPHATE TEST
Reference: Section 6.
Frequency: When any laboratory phosphatase test is
positive, or any doubt arises as to the adequacy of pasteurization due to noncompliance
with equipment, or requirements of Item 16p.
Criteria: Less than one (1) microgram per milliliter by Scharer Rapid Method or equivalent by other means.
(Refer to the SMEDP)
Apparatus: Field phosphatase test kit (obtainable from
Applied Research Institute, 40 Brighton Ave., Perth Amboy, NJ 08861), standards,
extra test tubes, stoppers or other approved phosphatase equipment.
Methods: The test is based on the detection of the phosphatase enzyme, a constituent
that is inactivated by pasteurization at 63°C (145°F) for thirty (30)
minutes or 72°C (161°F) for fifteen (15) seconds. When pasteurization
is faulty, some phosphatase remains and is detected through its action on phosphoricphenyl
esters, releasing phenol, which is measured quantitatively by the addition
of dibromo-or dichloro-quinonechlorimide to form an indophenol blue color.
Procedure: Refer to the SMEDP for details on phosphatase tests.
Corrective Action: Whenever a phosphatase test is positive, the cause shall be determined. Where
the cause is improper pasteurization, it shall be corrected and any milk or
milk products involved shall not be offered for sale.
III.EVAPORATING, DRYING AND DRY PRODUCT EQUIPMENT CLEANING
The presence of an appreciable quantity of phosphatase in milk and cream after
heat treatment has been traditionally regarded as evidence of inadequate pasteurization.
However, with the advent of modern HTST methods, evidence has been accumulating
that under certain conditions, the relationship between inadequate pasteurization
and the presence of phosphatase does not hold.
A number of investigators
who have studied HTST pasteurizing methods have concluded that while a negative
test can be obtained immediately after pasteurization, the same sample may
yield a positive test after a short period of storage, particularly if the
product is not continuously or adequately refrigerated. This phenomenon has
come to be known as reactivation.
Reactivation may occur in HTST pasteurized
products, after storage at temperatures as low as 10°C (50°F), although
34°C (93°F) is optimum. Products of high fat content generally produce
relatively more reactivable phosphatase.
Reactivation is greatest in products
pasteurized at about 110°C (230°F) but may occur in products pasteurized
at much higher temperatures and as low as 73°C (163°F).
It has been noted that an increase in holding time during pasteurization will reduce reactivation.
The addition of magnesium chloride to HTST processed milk or cream, after pasteurization
but before storage, accelerates reactivation. The difference in activity between
an adequately pasteurized sample, stored with and without magnesium, and an
inadequately pasteurized sample, stored with and without magnesium, forms the
basis of a test for differentiating reactivated from residual, inadequately
pasteurized, phosphatase.
IV. DETECTION OF PESTICIDES IN MILK
Any Regulatory Agency that has adopted this Ordinance should operate under
a control program that will insure that milk supplies are free from pesticide
contamination, in conformance with Section 2.
Pesticide compounds gain access
to milk by various routes. Insecticide contamination may result from any of
the following:
- Application to the lactating animals;
- Inhalation
of toxic vapors, by the animals, following application of insecticides to
their environment;
- Ingestion of residues in feed and water; and
- Accidental
contamination of milk, feed and utensils. Herbicide contamination may result
from residues on the lactating animals feed and in their water supply and/or
rodenticides may be present in milk as a result of accidental contamination.
At the present time, chlorinated hydrocarbon pesticides are the chief concern.
While there are other pest control compounds that are more toxic than the chlorinated
hydrocarbons, many of the agents in this latter group tend to accumulate in
the body fat of both lactating animals and human beings, and are secreted in
the milk of contaminated lactating animals. The accumulation of these toxic
agents in persons continually consuming contaminated milk may reach hazardous
concentrations.
Advances in residue analysis have resulted in a radical
decrease in the use of paper chromatographic screening procedures for milk,
because of its rather limited sensitivity. Regulatory Agencies can now routinely
detect residues as low as 0.01 ppm of many of the chlorinated organic pesticides.
Satisfactory screening procedures should, therefore, attain this level of sensitivity,
which usually necessitates the use of gas chromatography or thin layer chromatography.
General screening procedures of the latter two (2) types are described and discussed
in Volume 1 of the Pesticide Analytical Manual (PAM) published by FDA.
The need for closer scrutiny of milk supplies for pesticide residues has stimulated
considerable research in detection technology. The Regulatory Agency entering
upon a surveillance program should carefully check the available equipment
in relation to its adaptability to the indicated need.
While a schedule
of testing comparable to that for microorganisms, four (4) tests of individual
producer's milk during any consecutive six (6) months, would be desirable,
broad-spectrum procedures are too time consuming to render such a schedule
feasible. As a more practical approach, the following procedure is suggested:
- Test one (1) load of milk from each milk tank truck route, every six
(6) months, by a broad spectrum method and trace positive samples; or
- Test each producer's
milk four (4) times every six (6) months for the most common chlorinated
hydrocarbon pesticides, by available instrumental methodology.
NOTE: The above
testing disciplines may be applied conveniently to can milk supplies. Where
Procedure 1 is used, samples of commingled milk from known sources are drawn
from receiving station storage tanks. Sampling for Procedure 2 may be done
directly from the weigh tank.
V. DETECTION OF DRUG RESIDUES IN MILK
The problem of drug residues in milk is associated with their use in the treatment
of mastitis and other diseases. Failure to withhold milk from the market for
a sufficient length of time after treatment may result in the presence of drug
residues in milk. Such milk is undesirable for two (2) reasons:
- It comes from an unhealthy lactating animal; and
- It is adulterated.
The
allergenic properties of certain drugs in common use make their presence
in milk potentially hazardous to consumers. Also, substantial losses of byproducts
may be sustained by the milk industry each year because of the inhibitory
effects
of drug residues on the culturing process. Drug residues should be tested
for, using tests provided for in Section 6 of this Ordinance. These tests
are specified
in memoranda from the FDA. (Refer to the latest edition of M-a-85, M-a-86,
and the 2400 series forms for each specific test method.)
NOTE: Bacillus
stearothermophilus disk assay analysis performed to fulfill the provisions
of Section 7 of this Ordinance must be capable of detecting at least four
(4) of six (6) Beta lactam drugs at or below FDA reference levels. A zone
equal
to or greater than 16mm will be considered positive when the Bacillus stearothermophilus
disk assay is used, provided the 5ppb Beta lactam control zone is 16-20mm.
(Refer to the most recent FDA 2400 series form(s) for details related to
this analysis.)
VI. ANALYSIS OF MILK AND MILK PRODUCTS FOR VITAMIN A AND D3 CONTENT
Reference:
Section 6.
Frequency: Annually for each product type, or when any doubt
arises as to the adequacy of vitamin fortification. (Refer to Appendix O.)
Methods: Vitamin testing shall be performed using test methods acceptable to FDA and
other official methodologies that give statistically equivalent results to
the FDA methods.
REFERENCES
Official Methods of Analysis of AOAC INTERNATIONAL, 17th Edition, 2000.
Pesticide Analytical Manual, (PAM) available
from the U. S. Food and Drug Administration, Center for Food Safety and Applied
Nutrition, HFS-335, 5100 Paint Branch Parkway, College Park, MD 20740-3835.