Chapter 7

Establish Critical Limits

Objective

In this module, you will learn: How to define critical limits How to set critical limits for a CCP How to find sources of critical limit

information How to determine the relationship between

critical limits and operating limits

Principle 3

Establish critical limits

Critical Limit

A maximum and/or minimum value to which a biological, chemical or physical parameter must be controlled at a CCP to prevent, eliminate or reduce to an acceptable level the occurrence of a food-safety hazard

Examples of Critical Limits

Hazard CCP Critical Limitbacterial pasteurizer ≥161oF for ≥15

pathogens seconds

(biological) for elimination of

pathogens from milk

Examples of Critical Limits

Hazard CCP Critical Limitbacterial drying drying schedule:

pathogens oven oven temperature: 200oF

(biological) drying time: 120 min.

air flow rate: 2 ft3/min.

product thickness: 0.5 inches

(to achieve aw 0.85 to control

pathogens in dried foods)

Examples of Critical Limits

Hazard CCP Critical Limitbacterial acidification Batch schedule:pathogens product weight: 100 lbs.(biological) soak time: 8 hours

acetic acid concentration: 3.5% volume: 50

gallons(to achieve maximum pH of

4.6 to control Clostridium botulinum in pickled

foods)

Sources of Information on Critical Limits

General Source Examplesscientific publications journal articles, food science texts,

microbiology texts

regulatory guidelines state and local guidelines, tolerances and action levels; USDA guidelines, tolerances and action levels; FDA

guidelines, tolerances and action levels

Sources of Information on Critical Limits

General Source ExamplesFDA FDA Fish and Fisheries Products

Hazards and Controls Guidance Manual (referenced in Chapter 13)

Sources of Information on Critical Limits

General Source Examplesexperts NACMCF (National Advisory

Committee on Microbiological Criteria for Foods), thermal process

authorities; consultants, food scientists/ microbiologists, equipment manufacturers, sanitarians, university extension, trade associations

experimental studies In-house experiments; contract labs

Options for Controlling Hazards

Often a variety of options exist for controlling a particular hazard

The selection of the best control option and critical limit is often driven by practicality and experience

Monitoring for Pathogens at a Cook StepOption No. 1: Monitoring for Pathogens

Hazard– presence of pathogens (microbiological)

CCP– fryer

Critical Limit– no pathogens detected

(Not typically the best option)

Monitoring for Pathogens at a Cook Step Option No. 2: Monitoring Internal Temperature

Hazard– presence of pathogens (microbiological)

CCP– fryer

Critical Limit– minimum internal temperature of 150oF for 1

minute

Monitoring for Pathogens at a Cook Step Option No. 3: Monitoring Factors That Affect Internal Temp.

Hazard– presence of pathogens (microbiological)

CCP– fryer

Critical Limits– minimum fryer oil temperature of 350oF

– maximum patty thickness of 1/4 inch

– minimum cook time in the oil of 1 minute

Operating Limits Criteria that are more stringent than critical limits

and that are used by an operator to reduce the risk of a deviation

Operating limits may be selected for various reasons:– For quality reasons

– To avoid exceeding a critical limit

– To account for normal variability

Process Adjustment

An action taken by the firm to bring the process back within operating limits

Operating Limit/Process Adjustment Example

Figure 1

175

180

185

190

195

200

205

Time

Cooker Temperature

Lot 1

Process Adjustment Needed

Operating Limit

Critical LimitDe

gre

es F

Corrective ActionRequired

Operating Limit/Process Adjustment Example

Figure 2

175

180

185

190

195

200

205

Time

Cooker Temperature

Corrective ActionRequired

Lot 1

Process Adjustment Needed

Operating Limit

Critical Limit

Lot 2 Lot 3 Lot 4 Lot 5

De

gre

es F

Establishment of Critical Limits

Critical Control Point Critical LimitsCCP Cooker Cook at 212oF for 3

minutes

CCP - Weigh/Pack/Label All product containing sulfiting agent must

declare presence

HACCP Plan Form: Critical Limits

1.CCP

2.Hazard

3.CriticalLimits

What How Frequency Who

Monitoring

4. 5. 6. 9.Verification

8.CorrectiveAction(s)

10.Records

7.

HACCP Plan Form: Cooked Shrimp

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