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Comprehensive evaluation of temperatures within home refrigerators

January 2007
Food Protection Trends 27(3):16-21

Authors:

Sandria Godwin

Tennessee State University

Fur-Chi Chen

Tennessee State University

Edgar Chambers

Kansas State University

Richard Coppings

Jackson State Community College

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Microbial growth in many foods can be controlled by proper refrigeration. Thus, it is recommended that refrigerators be maintained at 40 o F (4.4°C) or below. However, no recent extensive studies have been reported that assess actual temperatures at which cold foods are stored over time within the home. The objective of this project was to evaluate the temperatures of refrigerators in 200 homes in the United States. Loggers were used to record temperatures each minute in several locations in each refrigerator. In some homes, a thermocouple was also placed in a commercially sealed hot dog and in a cup of yogurt. Data were analyzed using Excel and SPSS-PC. Mean temperatures were 35.5, 38.0 and 41.3ºF (1.9, 3.3 and 5.2°C) for the top shelf, bottom shelf and door, respectively, with 9, 25 and 61% of these areas having average temperatures above 40ºF (4.4°C). Over 66% of refrigerator door temperatures were above 40ºF (4.4°C) for more than eight hours per day. The temperature of the foods fluctuated less than the temperature of the surrounding air. Temperatures rose above the danger zone (above 40ºF or 4.4°C) for more than 2 hours a day for 33%, 45%, and 80% (top shelf, middle shelf, door, respectively) of refrigerators. Consumers need to check the temperature regularly and should be advised to store temperature-sensitive foods on the top shelf of the refrigerator when appropriate.

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Percentage of refrigerator compartments that exceeded 40°F (4.4°C) for specified lengths of time; N = 98, 187, and 197 for top shelf, bottom shelf, and door, respectively

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168 FOOD PROTECTION TRENDS | MARCH 2007

Food Protection Trends, Vol. 27, No. 3, Pages 168–173

2007, International Association for Food Protection

6200 Aurora Ave., Suite 200W, Des Moines, IA 50322-2864

*Author for correspondence: 615.963.5619; Fax: 615.963.5033

E-mail: sgodwin@tnstate.edu

A peer-reviewed article

ARTICLES

A Comprehensive Evaluation

of Temperatures within

Home Refrigerators

SANDRIA L. GODWIN,

1,2*

FUR-CHI CHEN,

EDGAR CHAMBERS IV,

RICHARD COPPINGS,

and DELORES CHAMBERS

Institute of Agricultural and Environmental Research, Tennessee State University, Nashville, TN 37209, USA;

Department of Family and Consumer Sciences, Tennessee State University, Nashville, TN 37209, USA; and

Sensory Analysis

Center, Department of Human Nutrition, Kansas State University, Manhattan, KS 66506, USA

SUMMARY

Microbial growth in many foods can be controlled by proper refrigeration. Thus, it is recommended

that refrigerators be maintained at 40

F (4.4°C) or below. However, no recent extensive studies have

been reported that assess actual temperatures at which cold foods are stored over time within the

home. The objective of this project was to evaluate the temperatures of refrigerators in 200 homes

in the United States. Loggers were used to record temperatures each minute in several locations in

each refrigerator. In some homes, a thermocouple was also placed in a commercially sealed hot dog

and in a cup of yogurt. Data were analyzed using Excel and SPSS-PC. Mean temperatures were 35.5,

38.0 and 41.3ºF (1.9, 3.3 and 5.2°C) for the top shelf, bottom shelf and door, respectively, with 9, 25

and 61% of these areas having average temperatures above 40ºF (4.4°C). Over 66% of refrigerator

door temperatures were above 40ºF (4.4°C) for more than eight hours per day. The temperature of

the foods ﬂuctuated less than the temperature of the surrounding air. Temperatures rose above the

danger zone (above 40ºF or 4.4°C) for more than 2 hours a day for 33%, 45%, and 80% (top shelf,

middle shelf, door, respectively) of refrigerators. Consumers need to check the temperature regularly

and should be advised to store temperature-sensitive foods on the top shelf of the refrigerator when

appropriate.

MARCH 2007 | FOOD PROTECTION TRENDS 169

INTRODUCTION

Data indicate that 25% of reported

foodborne illnesses are traced back to

food items that are consumed in the home

(13). However, little information is avail-

able to determine if any of these cases

are actually attributable to the domestic

environment and if, or to what extent, do-

mestic food handling practices contribute

to the problem. Although most outbreaks

are attributed to poor temperature control

of raw and cooked foods, many are asso-

ciated with cross contamination (14).

Regulatory agencies have also recog-

nized the importance of safe consumer

food-handling practices. A refrigerator is

recognized as one of the most important

pieces of equipment in the kitchen for

helping keep food safe. It helps maintain

the microbiological safety of the food

supply by inhibiting the growth of bacte-

ria that reproduce rapidly at temperatures

above 40°F (4.4°C). Consumers are told

to store their cold foods at 40°F (4.4°C)

or below (3, 5). However, some bacteria

such as Listeria monocytogenes, will continue

to thrive at cold temperatures and have

the potential to grow in the refrigerator

and subsequently cause serious illness and

possibly death. A recently released risk as-

sessment on Listeria in ready-to-eat foods

(6) noted that both refrigerator storage

temperature and duration of refrigerated

storage before consumption are impor-

tant factors in measuring the possible

public health impact to consumers from

foodborne listeriosis. The few studies that

have reported on cold storage of food in

homes have concluded that lack of ad-

equate practices for determining the tem-

perature of the refrigerator in the home

is a major problem (2, 4, 9). For example,

rather than using a thermometer, most

consumers rely on how cold the food

feels (8). Only 25% of consumers in one

study in the United States reported having

a thermometer in their refrigerator, and

most persons were unaware of the ideal

refrigerator temperature (12). In a study

conducted in Greece in which household

refrigerator temperature was assessed,

Sergelidis et al. (11) reported that 55% of

refrigerators had temperatures of 48°F

(8.9°C) or higher. Similarly, in a study of

elderly Britons, 70% had refrigerators that

were too warm for the safe storage of

food (10). In the most thorough study of

refrigerator temperatures, which was con-

ducted in the United Kingdom, James and

Evans (9) found that fewer than 2% of

refrigerators operated below 41

F (5.0°C)

at all times and that a third were consis-

tently over 41

F (5.0°C) Around 70% of

the refrigerators monitored were above

F (5.0°C) more than 50% of the time.

Data from a more recent study in New

Zealand show that 30% of refrigerators

were operating above 41°F (5.0°C) (7).

In spite of the need for compre-

hensive information on storage of cold

foods in the home environment, few

recent studies have been reported. No

studies have been found that investigated

actual temperatures at which cold foods

are stored within homes in the United

FIGURE 1. Distribution of mean temperatures for three locations in home refrigerators; N = 98, 187, and 197

for top shelf, bottom shelf, and door, respectively

170 FOOD PROTECTION TRENDS | MARCH 2007

States, variations of temperature within

different areas of the refrigerators, and

whether consumers are aware of cold

storage recommendations.

The objective of this project was to

evaluate the consistency and appropriate-

ness of temperatures for different loca-

tions within domestic refrigerators over

time. Temperature differences among

refrigerator areas and selected foods were

also assessed.

MATERIALS

AND METHODS

Temperatures from household re-

frigerators in routine use were collected

during visits to participants’ homes for

in-person interviews. The purpose of

the interview was to assess consumers’

knowledge and practices on handling and

storing refrigerated foods at home. Tem-

perature loggers (Precision Temperature

Data Logger, Spectrum 1000, accuracy +

0.1°F (0.05°C), were placed in 200 refrig-

erators in homes in Tennessee, Kansas,

and Florida. Generally, three loggers were

used, one placed on the bottom shelf of

the door panel, and the others in one or

more of four other locations, such as top

shelf, middle shelf, meat drawer, vegetable

bin, the site of each depending on the

model of the refrigerator. Items stored in

the refrigerators were kept in their origi-

nal arrangements. This report describes

results obtained from loggers placed on

the door panel and from those placed at

the back of the top and bottom shelves.

In some refrigerators, a thermocouple

also was placed in a commercially sealed

hot dog (111 refrigerators) or a cup of

yogurt (89 refrigerators), both of which

were provided by the researchers. These

foods, which are commonly found in re-

frigerators, represent solid and semi-solid

“ready-to-eat” foods of interest to food

safety researchers. Each logger recorded

the temperature every minute for at least

three consecutive days.

Temperature data were downloaded

for each refrigerator and evaluated by use

of Excel and SPSS-PC. Analysis included

calculations of means and standard

deviations for temperatures measured

by loggers placed on top and bottom

shelves and doors; minimum, maximum,

and range of temperatures, and frequency

distributions of numbers of refrigerators

and amount of time per day that those

refrigerators exceeded 40°F (4.4°C).

Although most scientists report

temperatures in Celsius, the tempera-

ture data in this paper are present-

ed not only in °C

for the scientific

community but also in °F, because

the Fahrenheit scale is familiar to Ameri-

can consumers and because refrigerator

temperature recommendations made in

such programs as FightBAC

are speci-

ed in °F.

FIGURE 2. Percentage of refrigerator compartments that exceeded 40°F (4.4°C) for speciﬁed lengths of time; N = 98, 187,

and 197 for top shelf, bottom shelf, and door, respectively

MARCH 2007 | FOOD PROTECTION TRENDS 171

RESULTS AND DISCUSSION

Figure 1 shows the distribution of

mean temperatures recorded in three

locations within home refrigerators. The

mean temperature was at or below the

currently recommended 40°F (4.4°C ) in

91% of the top shelves but in only 79% of

bottom shelves and 45% of refrigerator

doors. None of the mean temperatures

of the top shelves within each refrigera-

tor exceeded 45°F (7.2°C), the maximum

temperature that may have been recom-

mended when some of the refrigerators

in the study were manufactured, whereas

3.7 and 12.7 percent of bottom shelves

and doors, respectively, exceeded 45°F

(7.2°C). Overall temperatures (mean

± standard deviation) for top shelves,

bottom shelves, and doors were 35.5

± 3.96, 38.0 ± 3.98 and 41.3 ± 3.85°F

(1.9 ± 2.2, 3.3 ± 2.2 and 5.2 ± 2.1°C),

respectively. Nearly half of the top-shelf

areas, 46.9%, had mean temperatures of

35°F (1.7°C) or less, while 22.9% of bot-

tom shelves and only 4.6% of refrigerator

doors averaged 35°F (1.7°C) or less. Thus,

as expected, because the cold air enters

in the area close to the top shelf in most

refrigerators, this area was the coldest for

most of the refrigerators. Temperatures

fluctuated as much as 26°F (14.4°C)

within an area during the study. The

mean temperature fluctuation for

the top shelves was 10.1 ± 4.1°F

(5.6 ± 2.3°C), a range that was sig-

nificantly greater than the range for

the bottom shelves and refrigerator doors,

(6.7 ± 1.98 and 7.0 ± 2.81°F, or 3.7 ± 1.1

and 3.9 ± 1.6°C, respectively), again prob-

ably because this is where the cold air en-

ters the unit. However, it should be noted

that because the temperature uctuates

greatly, the time at which the consumer

checks the temperature could be critical

in determining whether the food is being

kept cold enough or not, and whether

adjustments to the temperature or repairs

to the refrigerator are warranted.

The length of time each refrigerator

compartment exceeded 40°F (4.4°C) is

displayed in Fig. 2. The air around the top

shelf was the coldest for almost all refrig-

erators. The temperature never exceeded

40°F (4.4°C) for 40% of them, in contrast

to 33.7% of bottom shelves and only

9% of the doors. Thus, the consistently

high temperature of the door is a major

concern. When the temperature of the air

exceeded 40°F (4.4°C), it was for shorter

periods each day, from 1–20 min up to 2–4

h, for the top shelves than for the other

areas. Only 2.4% of top shelves continu-

ously exceeded 40

F (4.4°C). In contrast,

FIGURE 3. Distribution of mean temperatures for hot dogs and yogurt in home refrigerators; N = 111, and 89 for hot dogs

and yogurt, respectively

172 FOOD PROTECTION TRENDS | MARCH 2007

a greater proportion of refrigerator

doors exceeded 40°F (4.4°C) in each of

the longer intervals, beginning with the

4–8 h period. Over one third (39.3%)

of doors and 11.1% of bottom shelves

were continuously above recommended

refrigerator temperature.

Since the temperature of the food,

not of the air, is probably the most impor-

tant factor in temperature control, we also

recorded temperature in thermocouples

placed in hot dogs and yogurt cups.

Lower mean temperatures were recorded

in a greater percentage of commercially

sealed hotdogs than of yogurt containers,

as shown in Fig. 3. The mean temperature

was 36.3°F (2.4°C) for hot dogs and

37.1°F (2.8°C) for the yogurt. The hot

dog averaged 0.2°F (0.1°C) colder, and the

yogurt 0.7°F (0.4°C) colder, than the sur-

rounding air. Therefore, the hot dogs and

yogurt had mean temperatures slightly less

than those recorded from temperature

sensors placed in the same refrigerator in

the same area, indicating that these foods

maintained the low temperature better.

Air temperature within a refrigerator

would be expected to change rapidly as

the door is opened, foods are added or

taken out, cold or warm air enters, or the

defrost cycle occurs.

Only 18 of the 200 refrigerators

evaluated in this study (9%) contained a

refrigerator thermometer when we arrived

in the home. Of additional concern was

the fact that for those homes where a ther-

mometer was present in the refrigerator,

the respondents reported that they rarely

or never checked it.

Thus, circumstances do appear to

exist in many homes that could lead to

increased microbial growth in refriger-

ated foods, and consequently lead to a

higher risk of consumers contracting a

foodborne illness. A large percentage

of refrigerators in the current study

were not maintaining the recommended

temperature of 40°F (4.4°C) or below

continuously. The top shelf had the lowest

mean temperature, probably because the

cold air inlet is located in this area in most

refrigerators. The door was too warm in

the majority of refrigerators and stayed

that way a large percentage of the time;

indeed, nearly 40% of refrigerator doors

were above 40

F (4.4°C) all of the time.

Thus, foods that are potentially hazard-

ous, such as milk and eggs, should not be

stored on the door, which is of concern

because many refrigerators have compart-

ments on the door especially designed for

storage of these foods. Consumers should

be educated to place highly perishable

foods in the main compartment of the

refrigerator and use the refrigerator door

only for items that do not spoil readily,

such as condiments (mustard, ketchup,

etc.), highly salted foods such as pickles

or olives, and cold beverages.

All refrigerators should be equipped

with a thermometer that should be

checked regularly, which is not the cur-

rent situation, since few consumers have

refrigerator thermometers (only 9% in

the current study). This gure of 9%

is much lower than gures reported by

other researchers, who asked consumers

if they had a thermometer in their refrig-

erator (1). There is a clear need to inform

consumers of the value of refrigerator

thermometers and to encourage their

correct use.

An additional problem arises in

that refrigerator thermometers are of

little value if not properly used. When

asked, 33% of consumers with refrigera-

tor thermometers replied that they had

not checked them within the last week

(8). We recommend that the refrigerator

thermometer be checked frequently, be-

cause the large uctuation in refrigerator

temperatures reported herein suggests

that infrequent checks would not reliably

indicate overall temperature maintenance.

Observing the temperature initially in

the morning would provide insight into

the ability of the refrigerator to main-

tain proper temperature. Checking the

thermometer temperature at different

times during the day following periods

of normal use would give consumers in-

formation regarding if and how often the

temperature in their refrigerator exceeds

40°F (4.4°C). We further recommend that

the thermometer be placed on the door,

since this is nearly always the warmest part

of a domestic refrigerator and thus would

provide the best indication as to whether

the entire refrigerator is cold enough.

In our previous study, a signicant

proportion (45%) of consumers reported

that they had changed the temperature

setting within their refrigerator in the

past six months, suggesting an aware-

ness of the need to maintain an adequate

temperature (8). The decision to change

the temperature setting, however, usu-

ally was based on intuition; consumers

judged refrigerator temperature most

commonly by assessing the temperature

of cold beverages. Clearly, these methods

are unreliable. Such decisions should be

based on observations from a refrigerator

thermometer.

Consumers need to realize the im-

portance of maintaining cold foods at the

recommended temperature in the home

to reduce the risk of foodborne illness.

Moreover, it is imperative that consum-

ers recognize that the responsibility for

controlling food temperature in the home

rests on them. Regulatory agencies such

as the Food and Drug Administration, US

Department of Agriculture, and health

departments can not help guarantee the

safety of foods once these have been

purchased. Consumers need to adhere to

agency recommendations for handling

and storing foods to best avoid food-

borne illness. Researchers and educators

need to provide instruction to consum-

ers to ensure that they are aware of and

understand current recommendations.

Furthermore, we believe that it would be

helpful if manufacturers were required to

install thermometers in all refrigerators

and include instructions for their proper

use, as well as information on the safe

storage of refrigerated foods.

ACKNOWLEDGMENTS

This material is based on work

supported by Food and Drug Admin-

istration under cooperative agreement

FD-U-001950, and US Department of

Agriculture under Project TENX-0402-

FSHNT23.

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Background: Food-borne pathogens are one of the most important problems in less developed and developed countries. Commercial refrigerators are a potential source of fungal contamination that causes food spoilage, food-borne intestinal infectious diseases or mycotoxin diseases. Objectives: The purpose of this study was to determine the distribution of psychotropic fungi in food storage refrigerators (n = 50) with temperatures above and below 0ºC at selected restaurants (n = 25) located in the city of Ahvaz, Iran. Methods: Samples were collected from the surfaces of the refrigerators by using sterile swab sticks pre-moistened with sterile distilled water, and then each collected sample was plated out on Sabouraud dextrose agar medium. Finally, all fungi were counted and identified based on macroscopic and microscopic characteristics. Results: According to our results, 100% of the sample refrigerators showed fungal contamination. Cladosporium sp. (42.34%) and Mucor sp. (0.06%) had the highest and the lowest frequency of fungi recovered from our research, respectively. Furthermore, the P value calculated indicated a significant correlation between refrigerators above 0ºC and refrigerators below 0ºC (P < 0.00001). Conclusions: The presence of fungi in commercial refrigerators could be an indicator of a potential source of food spoilage and food-borne diseases. Therefore increased education, and proper packaging and refrigerator management are recommended since regular cleaning of these refrigerators is important in order to prevent food-borne diseases and other health risks.

Concerns and solutions for raw milk from vending machines

Article

Jul 2019

The sale of raw milk from vending machines is allowed in several European Countries. Since unpasteurized milk could harbor foodborne pathogens, the boiling treatment is highly recommended before consumption. In this study, the effect of storage temperatures, generally recorded in domestic refrigerators, as well as the effect of domestic boiling and industrial microwaving on the microbiological, and nutritional quality of raw bovine milk from vending machines was evaluated. Results highlighted that some microbial groups increased during the storage at 8°C. Noticeable, Listeria spp., even if initially present in low amounts, reached levels that would be a cause of concerns. Based on these results, the effects of domestic boiling and microwaving on the survival of L. innocua intentionally added was evaluated, as well as the nutritional features of treated milk. Both treatments were able to eliminate L. innocua, but only microwaving preserved the nutritional quality of milk. This study presents the application of microwaving as an alternative treatment to enhance the quality of raw bovine milk. Domestic storage conditions (especially refrigeration temperatures and time) produce a strong decay in the microbiological quality of the product and Listeria levels might become a real concern. In addition, boiling treatment, imposed by law prior to milk consumption, produces a further depletion of the nutritional quality, producing a strong decay in thermolabile compounds. A suitable solution for heat treatment of raw milk from vending machines could be represented by microwaving at 780 W for 1.35 min. This datum could serve for setting a specific program in domestic microwave ovens for sanitization of raw milk in home environments.

Effect of antimicrobial treatments applied individually and in combination on the growth of Listeria monocytogenes in Queso Fresco at 3 different temperatures

Article

Jul 2022

Queso fresco (QF), a fresh soft cheese, is one of the most popular Hispanic cheeses in the United States and is frequently associated with Listeria monocytogenes outbreaks. Listeria monocytogenes can grow and thrive at room temperature as well as refrigeration temperatures. A combination of antimicrobial agents provides a larger spectrum of listeriostatic and listeriocidal activity resulting in a more effective approach toward the control of L. monocytogenes. In this study, we evaluated the efficacy of 3 Food and Drug Administration-approved generally recognized as safe (GRAS) antimicrobials, nisin (NIS), lauric arginate ethyl ester (LAE), and ε-polylysine (EPL), and the endolysin PlyP100 individually and in combination for control of L. monocytogenes in QF at 4°C, 7°C, and 10°C. Additionally, growth curves of L. monocytogenes were obtained in BHI broth and QF at these temperatures. In order for an antimicrobial to be considered a postlethality treatment for L. monocytogenes, it should not allow an increase of more than 2-log over the product's shelf life. Three treatments, PlyP100, PlyP100 + NIS, and EPL + LAE, effectively kept the pathogen below the 2 log growth threshold at 4°C. However, at 7°C and 10°C, none of the antimicrobial treatments could inhibit L. monocytogenes growth (i.e., <2 log). Overall, our results suggest the importance of considering the effect of cold storage temperatures above 4°C on the antilisterial efficacy of antimicrobial treatments in QF.

Blueberry supply chain: Critical steps impacting fruit quality and application of a boosted regression tree model to predict weight loss

Article

Sep 2021
POSTHARVEST BIOL TEC

Blueberries have increased in popularity in recent years due to their nutritional benefits and sensory characteristics. However, to preserve quality and extend shelf-life, they need to be maintained at refrigerated temperatures and high relative humidity, conditions that are not routinely met along the supply chain. Poor temperature management leads to quality deterioration, increasing waste/losses along the supply chain. This study examined the impact of each step along the supply chain on the physichochemical quality and shelf-life of blueberries, identifying the most critical steps from field to consumption. The following steps were identified as critical in the blueberry supply chain: shipping to distribution centre (DC) (72 h at 5 °C), store display (48 h at 15 °C), and consumer (48 h at 20 °C). Given the economic importance of weight loss and its link to fruit quality and shelf-life, a boosted regression tree (BRT) model was built to predict weight loss using the post-harvest environmental conditions of a simulated supply chain applying different temperature-time scenarios. The model explained 84 % of the variance on the test set and highlighted the interactions of supply chain conditions on weight loss.

Food safety knowledge and practice among elderly people living at home

Article

Full-text available

Dec 1998

To assess the food storage knowledge and practice of elderly people living at home. Three phase survey data collection: face to face interviews; dietary diaries with a food frequency questionnaire; and follow up interviews. Urban Nottingham. 809 elderly people (aged 65+) randomly selected from general practitioner lists. Respondent's refrigerator temperature; knowledge of freezer star rating; understanding of "use by" and "sell by" dates; reported ability to read food product safety labels. From a weighted total of 645 refrigerators measured, 451 (70%) were too warm for the safe storage of food (> or = 6 degrees Celsius). Only 41% of respondents (n = 279) knew the star rating of their freezer. Within a smaller sub-sample knowledge of the "use by" and "sell by" dates was good, but 45% of these respondents reported difficulty reading food labels. The storage of foods at inappropriate temperatures was not independent of socioeconomic or demographic status, and tended to be more likely among the poorer and those not living alone. Food storage practices among the majority of elderly people interviewed in this study do not meet recommended safety standards to minimise the risk of food poisoning.

Study Finds Consumer Food Safety Knowledge Lacking

Article

Jan 2005

Proper cooling of foods is known to reduce spoilage and help prevent food-borne illnesses. Nonetheless, little is known about consumers' awareness of guidelines regarding appropriate refrigeration of food or their actual refrigeration practices. Focus groups of consumers of common ethnic backgrounds were designed to evaluate food safety knowledge and home refrigeration practices. Differences were found among ethnic and age groups regarding knowledge of proper refrigeration practices and general food safety, as well as common refrigeration practices. Most participants did not know proper refrigerator temperatures, and none used refrigerator thermometers. The most common sources of food safety information were relatives and extension educators. Eight focus groups of common ethnicity were conducted involving a total of 53 persons. Ethnic groupings included Hispanic, African American, and Caucasian. Comparisons of responses from the eight groups provided insights into consumer practices by ethnic group, whereas the opinions of minority individuals might be overshadowed in focus groups of mixed ethnicity. Although misconceptions were apparent, participants offered many suggestions for avoiding food-borne illnesses (Table 1). They were less certain when the questions focused on refrigeration and cooling practices. Few participants knew the correct refrigerator temperature, and none had a refrigerator thermometer. Most judged the refrigerator temperature from everyday experience (e.g., "I feel the milk to see if it is cold"). It was commonly thought that the dial setting needed to be changed in the summer for food to stay cold.

Household Food Preparers' Food-Safety Knowledge and Practices Following Widely Publicized Outbreaks of Foodborne Illness

Article

Sep 1997

There has been extensive media coverage of the Pacific Northwest outbreak of foodborne illness caused by Escherichia coli O157:H7 in 1993 and continuing smaller incidences of both E. coli and salmonella transmission by food. An increase in consumer awareness and knowledge of microbial food safety was expected as a result. A telephone survey of Oregon food preparers (using a random-digit-dialing household sample) in December 1995 and January 1996 revealed that knowledge about foodborne illness was greater than in previous studies. Of the 100 respondents, 88% named appropriate foods as being at high risk for food poisoning. Salmonella contamination was recognized as a problem in food by 99%, E. coli by 100%, but campylobacter by only 7%. Major foods which have been associated with salmonella were named correctly by 90% and with E. coli by 87%. Although raw or rare meats or fish were rarely eaten or ordered by respondents, hamburgers were frequently requested to be cooked to "medium" doneness. Many said they would thoroughly cook food contaminated with bacteria to make it safe to eat (56% for salmonella and 59% for E. coli) but 40% responded that the foods either couldn't be made safe to eat or that they didn't know of a way. Respondents in general could not identify specific groups of people especially at risk for foodborne illness. Educational efforts should focus on risk groups and ways that consumers can prevent foodborne illness.

Food safety knowledge and practices of consumers in the USA

Article

Jul 2007
Int J Consum Stud

Julie A Albrecht

Use of safe food handling practices in the home could reduce the number of foodborne illnesses. The objective of this project was to obtain baseline data on the safe food handling knowledge and practices of consumers to aid in the development of effective educational programmes. A food handling questionnaire was developed and completed by 426 Nebraskan respondents. Knowledge and practice questions were based on the most important contributory factors in reported foodborne illness outbreaks. Knowledge scores (correct responses) ranged from 2 to 29 with a mean of 20 ± 4. When compared with the knowledge score, the respondents' education level, where they lived and their sex were statistically significant. Almost all (96%) of the respondents stated that they practised safe food handling when persons were infected. Approximately half of the respondents indicated that they practised safe food handling when handling contaminated raw foods and using foods from unsafe sources. About 45% of the respondents inappropriately left foods at room temperature. One-third of the survey respondents improperly held hot foods. Cross-contamination was a concept understood by 75% of the respondents. Results indicate that food safety education should be targeted on specific groups who are less knowledgeable about safe food handling practices. Results also indicate that a number of respondents knew proper food handling concepts but did not put those concepts into practice. Therefore, increasing the adoption of safe food handling practices by consumers should become an important aspect for educators in food safety educational programmes.

Consumer handling of chilled foods: Temperature performance

Article

Dec 1992
INT J REFRIG

Chilled foods are stored for periods of between a few hours and many days in domestic refrigerators. However, there are little published data on the temperature performance of domestic refrigerators within the home. A survey has been taken in 252 households in the UK and some of the results are presented in this paper. The refrigerators investigated in the survey were found to have an overall mean temperature of approximately 6°C, which ranged from 11.4 to −0.9°C. Temperature ranges over the whole refrigerator varied from 4.5 to 30.5°C with 3.7% of the total being warmer than 20°C. On average 29.9% of refrigerators operated below 5°C and 66.7% operated below 7°C. Few refrigerators (7.3%) ran, on average, above 9°C. No refrigerator characteristic (apart from type) could be related to temperatures or temperature distribution in the refrigerators investigated.RésuméLes aliments réfrigérés sont entreposés dans les réfrigérateurs domestiques, pour des périodes allant de quelques heures à plusieurs jours. Cependant, peu de données ont été publiées sur la performance des réfrigérateurs domestiques en matière de température, au domicile des consommateurs. Une enquête a été effectuée auprès de 252 ménages au Royaume Uni, et on présente quelques résultats dans cet article. Les réfrigérateurs considérés dans l'enquête avaient une température globale moyenne d'approximativement 6 deg C (elle variait de 11,4 à −0,9 deg C). Les plages de température globale allaient de 4,5 à 30,5 deg C, mais pour 3,7% des réfrigérateurs, la température était supérieure à 20 deg C. En moyenne, 29,9% des réfrigérateurs fonctionnaient à une température inférieure à 5 deg C, et 66,7% à une température inférieure à 7 deg C. Peu de réfrigérateurs (7,3%) fonctionnaient à une température supérieure à 9 deg C. Aucune caractéristique des réfrigérateurs, mis à part leur type, ne pouvait avoir une incidence sur les températures ou sur la distribution de température, dans les réfrigérateurs étudies.

Consumer Food Handling in the Home: A Review of Food Safety Studies

Article

Feb 2003

Epidemiological data from Europe, North America, Australia, and New Zealand indicate that a substantial proportion of foodborne disease is attributable to improper food preparation practices in consumers' homes. International concern about consumer food safety has prompted considerable research to evaluate domestic food-handling practices. The majority of consumer food safety studies in the last decade have been conducted in the United Kingdom and Northern Ireland (48%) and in the United States (42%). Surveys (questionnaires and interviews), the most frequent means of data collection, were used in 75% of the reviewed studies. Focus groups and observational studies have also been used. One consumer food safety study examined the relationship between pathogenic microbial contamination from raw chicken and observed food-handling behaviors, and the results of this study indicated extensive Campylobacter cross-contamination during food preparation sessions. Limited information about consumers' attitudes and intentions with regard to safe food-handling behaviors has been obtained, although a substantial amount of information about consumer knowledge and self-reported practices is available. Observation studies suggest that substantial numbers of consumers frequently implement unsafe food-handling practices. Knowledge, attitudes, intentions, and self-reported practices did not correspond to observed behaviors, suggesting that observational studies provide a more realistic indication of the food hygiene actions actually used in domestic food preparation. An improvement in consumer food-handling behavior is likely to reduce the risk and incidence of foodborne disease. The need for the development and implementation of food safety education strategies to improve specific food safety behaviors is reviewed in this paper.

Article

Jul 2006

Government agencies have recently emphasized the importance of food safety. Reducing the risk of foodborne illnesses within the home requires American consumers to put government refrigeration and freezer recommendations into practice; however, little research has been conducted regarding the use of proper refrigeration and freezer storage practices by consumers. A random sample survey was conducted to examine attitudes and practices of proper refrigeration and storage techniques of consumers in Peoria County, Illinois, and to determine whether gender, age, education, and income level have an effect on these variables. Eighty-one of 500 random sample surveys mailed were returned between 10 January and 15 February 2005. The majority of the participants were female (56, 69.1%), were 50 to 59 years old (18, 22.2%), had a bachelor's degree (33, 40.7%), and had a reported total household income of 60,000 dollars or greater (39, 91.4%). Average attitudinal scores indicated that participants thought it was important to take proper steps to prevent foodborne illnesses in the home; however, 68.8% of participants scored poorly on the practice portion of the survey. Only 12.3% of participants stated that they had a thermometer in their freezer, and 24.7% had one in their refrigerator. Eighty-four percent of respondents did not store eggs correctly in the refrigerator. No significant relationships (P < 0.05) were found within this sample population. These results suggest that further evaluation of consumer practices and attitudes is needed to better understand consumers so that they can be effectively educated about the prevention of foodborne illnesses at home.

Center for Food Safety and Applied Nutrition Foodborne illness: What consumers need to know

Dec 2001

Drug Food
Administration

Food and Drug Administration. Center for Food Safety and Applied Nutrition. 2001. Foodborne illness: What consumers need to know. Available at http://www.foodsafety. gov/~dms/fsefborn.html. Accessed November 1, 2006.

Center for Food Safety and Applied Nutrition Food Safety Inspection Service Centers for Disease Control Quantitative assessment of relative risk to public health from foodborne Listeria monocytogenes among selected categories of ready-to-eat foods

Dec 2003

Drug Food
Administration

Food and Drug Administration. Center for Food Safety and Applied Nutrition. Food Safety Inspection Service. Centers for Disease Control. 2003. Quantitative assessment of relative risk to public health from foodborne Listeria monocytogenes among selected categories of ready-to-eat foods. Available at http://www.foodsafety.gov/~dms/ lmr2-toc.html. Accessed November 1, 2006.

ADA) and ConAgra Foods Foundation Home food safety refrigeration survey Available at: http://www.homefoodsafety.org

Jan 2001

American Dietetic Association

American Dietetic Association (ADA) and ConAgra Foods Foundation. 2001. Home food safety refrigeration survey. Available at: http://www.homefoodsafety.org/ pages/media/releases/apr6_2001_ key.jsp. Accessed November 1, 2006.