The software is useful for teaching the principles of risk assessment in relation to food safety, and highlighting

factors contributing to food safety risk. It has also been used in ranking the risk of various product/pathogen

combinations.As with any such software the outputs are only as reliable as the data entered, and users are urged to remain aware

of the intended uses and limitations of the program. Please note that the Risk Ranger spreadsheet is not protected

and changes may have been made, either deliberately or inadvertently. If you are uncertain of the integrity of the

copy of the spreadsheet you are currently using, a new copy may be downloaded from

This version has been modified from the original described in the above publication by reducing the weight given

to Moderate, Mild and Minor hazard severity classifications (Question 1) by a factor of 10. This preserves the

risk rank scaling (0 - 100) and its original interpretation but better reflects the severity of fatal disease compared to

non-life threatening hazards. Question 3 has also been slightly modified to enable better discrimination of serving

frequency.

This is Version 2 of "Risk Ranger", software developed at the Australian Food Safety Centre of Excellence, to assist

understanding of the process of microbial food safety risk assessment.

Welcome.

The software has been peer-reviewed and has been published in the International Journal of Food Microbiology

(Ross, T. and Sumner, J.L. (2002). A simple, spreadsheet-based, food safety risk assessment tool. International

Journal of Food Microbiology , 77:39-53) which fully describes the logic behind the system as well as its limitations.

The software is useful for teaching the principles of risk assessment in relation to food safety, and highlighting

factors contributing to food safety risk. It has also been used in ranking the risk of various product/pathogen

combinations.As with any such software the outputs are only as reliable as the data entered, and users are urged to remain aware

of the intended uses and limitations of the program. Please note that the Risk Ranger spreadsheet is not protected

and changes may have been made, either deliberately or inadvertently. If you are uncertain of the integrity of the

copy of the spreadsheet you are currently using, a new copy may be downloaded from

This version has been modified from the original described in the above publication by reducing the weight given

to Moderate, Mild and Minor hazard severity classifications (Question 1) by a factor of 10. This preserves the

risk rank scaling (0 - 100) and its original interpretation but better reflects the severity of fatal disease compared to

non-life threatening hazards. Question 3 has also been slightly modified to enable better discrimination of serving

frequency.

This is Version 2 of "Risk Ranger", software developed at the Australian Food Safety Centre of Excellence, to assist

understanding of the process of microbial food safety risk assessment.

Welcome.

The software has been peer-reviewed and has been published in the International Journal of Food Microbiology

(Ross, T. and Sumner, J.L. (2002). A simple, spreadsheet-based, food safety risk assessment tool. International

Journal of Food Microbiology , 77:39-53) which fully describes the logic behind the system as well as its limitations.

The software is useful for teaching the principles of risk assessment in relation to food safety, and highlighting

factors contributing to food safety risk. It has also been used in ranking the risk of various product/pathogen

combinations.As with any such software the outputs are only as reliable as the data entered, and users are urged to remain aware

of the intended uses and limitations of the program. Please note that the Risk Ranger spreadsheet is not protected

and changes may have been made, either deliberately or inadvertently. If you are uncertain of the integrity of the

copy of the spreadsheet you are currently using, a new copy may be downloaded from

This version has been modified from the original described in the above publication by reducing the weight given

to Moderate, Mild and Minor hazard severity classifications (Question 1) by a factor of 10. This preserves the

risk rank scaling (0 - 100) and its original interpretation but better reflects the severity of fatal disease compared to

non-life threatening hazards. Question 3 has also been slightly modified to enable better discrimination of serving

frequency.

This is Version 2 of "Risk Ranger", software developed at the Australian Food Safety Centre of Excellence, to assist

understanding of the process of microbial food safety risk assessment.

Welcome.

The software has been peer-reviewed and has been published in the International Journal of Food Microbiology

(Ross, T. and Sumner, J.L. (2002). A simple, spreadsheet-based, food safety risk assessment tool. International

Journal of Food Microbiology , 77:39-53) which fully describes the logic behind the system as well as its limitations.

Thus, the chosen range extends over 17.56 orders of magnitude and, as a result, an

increment of six Risk Ranking units, corresponds approximately to a factor of 10

difference in the absolute risk estimate.

The Risk Ranking value is a simplified measure of relative risk. Because of the magnitude of differences in risk under situations and scenarios of

interest a logarithmic scale is used and, for convenience, a scale between 0 and 100

was chosen.We set the upper limit of the scale (100) as the worst imaginable scenario, i.e. where

every member of the population eats a meal that contains a lethal dose of the hazard

every day.

To set the lower end of the scale we arbitrarily chose a probability of mild food-borne

illness of less than or equal to one case per 10 billion people (greater than current

global population) per 100 years as a negligible risk. The risk in this situation is 2.75

x10-18 times that of the scenario to which the upper end of the scale corresponds.

Thus, the chosen range extends over 17.56 orders of magnitude and, as a result, an

increment of six Risk Ranking units, corresponds approximately to a factor of 10

difference in the absolute risk estimate.

The Risk Ranking value is a simplified measure of relative risk. Because of the magnitude of differences in risk under situations and scenarios of

interest a logarithmic scale is used and, for convenience, a scale between 0 and 100

was chosen.We set the upper limit of the scale (100) as the worst imaginable scenario, i.e. where

every member of the population eats a meal that contains a lethal dose of the hazard

every day.

To set the lower end of the scale we arbitrarily chose a probability of mild food-borne

illness of less than or equal to one case per 10 billion people (greater than current

global population) per 100 years as a negligible risk. The risk in this situation is 2.75

x10-18 times that of the scenario to which the upper end of the scale corresponds.

1 Hazard Severity

6

2

7

3

If "OTHER" enter "number

of days between a 100g 10

48

5

Population considered:

9

A. SUSCEPTIBILITY AND SEVERITY

How susceptible is the population of interest ?

B. PROBABILITY OF EXPOSURE TO FOOD

Frequency of Consumption

Size of Consuming Population

Proportion of Population Consuming the Product

19,500,000If "OTHER" please

specify:

6,500,000

Hazard Severity 0.001 0.00

How susceptble is 1

Frequency of contamination 0.1

Effect of Process 1.00E-03

Effect of Meal Preparation 1.00E-03

Potential for Recontamination 0.01

Effect of P/Process Control 1

Increase req. for a toxic dose 0.1

Consumption frequency of consumers 0.142465753

Proportion of Population Consuming the Product 2.50E-01

Size of Total Population 1.95E+07

11(fraction of population considered) 1

10

If "OTHER" enter a percentage

value between 0 (none) and 100 0.0001%

Effect of Processing 11

If "OTHER" enter a value that

indicates the extent of risk

increase 1.00E-03

If "OTHER" enter a percentage

value between 0 (none) and 100

(all)

9.00%

C. PROBABILITY OF FOOD CONTAINING AN INFECTIOUS DOSE

Probablity of Contamination of Raw Product per

Serving

How effective is the post-processing control

system?

Is there potential for recontamination after

processing ?

P morbid dose (general response) 0.000001

Total exposures to food per day 6.95E+05

P morbidity (normal) 0.69452055

P exposure/day 0.03561644

253.5

If "other", what is the increase

(multiplic-ative) needed to reach an

infectious dose ?

1.E+02

If "other", enter a value that indicates

the extent of risk increase 1.00E-03

total predicted illnesses/annum in

population of interest2.54E+02

C. PROBABILITY OF FOOD CONTAINING AN INFECTIOUS DOSE

What increase in the post-procssing contamination

level would cause infection or intoxication to the

average consumer?

Effect of preparation before eating

probability of illness per day per

consumer of interest

(Pinf x Pexp )

RISK ESTIMATES

1.42E-07

3.56E-11

0.000001

40

RISK RANKING

( 0 to 100)

total predicted illnesses/annum in

population of interest2.54E+02

"COMPARATIVE

RISK" in population of

interest######

"COMPARATIVE RISK"

in population of interest######

1. Hazard Severity

SEVERE hazard - causes death to most victims 1MODERATE hazard - requires medical intervention in most cases0.01MILD hazard - sometimes requires medical attention 0.001MINOR hazard - patient rarely seeks medical attention 0.0001

3 0.001

GENERAL - all members of the population 1

SLIGHT - e.g., infants, aged 5

VERY - e.g.,neonates, very young, diabetes, cancer, alcoholic etc 30

EXTREME - e.g., AIDS, transplants recipients, etc. 200

1 1

Rare (1 in a 1000) 0.001

Infrequent (1 per cent) 0.01

Sometimes (10 per cent) 0.1

Common (50 per cent) 0.5

All (100 per cent) 1

OTHER 0.0000500%

3 1.00E-01

4a. Effect of ProcessThe process RELIABLY ELIMINATES hazards 0

The process USUALLY (99% of cases) ELIMINATES hazards 0.01

The process SLIGHTLY (50% of cases) REDUCES hazards 0.5

The process has NO EFFECT on the hazards 1

The process INCREASES (10 x) the hazards 10

The process GREATLY INCREASES (1000 x ) the hazards 1000

OTHER 1.00E-03

7 0.001

4b. Effect of Preparation for MealMeal Preparation RELIABLY ELIMINATES hazards 0

Meal Preparation USUALLY ELIMINATES (99%) hazards 0.01

Meal Preparation SLIGHTLY REDUCES (50%) hazards 0.5

Meal Preparation has NO EFFECT on the hazards 1

OTHER 1.00E-03

5 1.00E-03

NO 0.00

YES - minor (1% frequency) 0.01

YES - major (50% frequency) 0.50

OTHER 0.09

2 0.01

2. How susceptible is the consumer ?

5. Is there potential for recontamination ?

6. How effective is the post-processing control system?

3. Frequency of Contamination

WELL CONTROLLED - reliable, effective, systems in place (no increase in pathogens)1

CONTROLLED - mostly reliable systems in place (3-fold increase) 3

NOT CONTROLLED - no systems, untrained staff (10 -fold increase) 10

GROSS ABUSE OCCURS - (e.g.1000-fold increase) 1000

NOT RELEVANT - level of risk agent does not change 1

5 1

WORST CASE 0

7. How much increase is required to

reach an infectious or toxic dose?none 1

slight (10 fold increase) 0.1

moderate (100-fold increase) 0.01

significant (10,000-fold increase) 0.0001

OTHER 1.E-02

2 0.1

daily 365

weekly 52 600000

monthly 12

a few times per year 3

OTHER 36.5

2 52

all (100%) 1

most (75%) 0.75

some (25%) 0.25

very few (5%) 0.05

3 0.25

Australia 19500000

ACT 321000

New South Wales 6595000 19500000

Northern Territory 198000

Queensland 3595000

South Australia 1547000

Tasmania 491000

Victoria 4847000 6500000

Western Australia 1905000

OTHER 6,500,000

1 19500000

based on Question 2 selection 1

From ABS 1998 stats, scaled up to 2000 estimates of total

population. Probably introduces some error, e.g. in Tas,

where popn is declining.

8. Frequency of Consumption

9. Proportion of Consuming Population

Size of Affected Population

10. Size of Consuming Population

From ABS 1998 stats, scaled up to 2000 estimates of total

population. Probably introduces some error, e.g. in Tas,

where popn is declining.