Table 1-1
Introduction
As more retail food operations across the U.S. and throughout the world
compete to feed consumers, it becomes essential that uniform hazard analysis
and control guidelines for producing, buying, and selling food products
be developed. These guidelines must be based on science and validated
in actual operation. At this time, consumers in the U.S. are doing
less food preparation themselves and are dining out and/or are relying
on retail food outlets for ready-prepared items. Food operations,
as defined in this document, include: food markets where food is
sold to be prepared in the home; food preparation and foodservice establishments
that include restaurants, institutional foodservice units, street vending
operations, hotel and lodging operations, military commissaries; and even
the home, which is actually a miniature foodservice unit.
Food science and technology have improved the understanding of the potential
microbiological, chemical, and physical hazards in foods. This knowledge
can be used to determine the criteria necessary to assure that food products
and commodities meet consumer safety expectations with an acceptable risk
at the raw material level, the distributor level, and the consumer level.
International trade and tourism will be enhanced throughout the world when
there is a clearer understanding between the producer, retailer/supplier,
and the buyer of food concerning the potential hazards in food and the
level of risk associated with consuming a food.
Beginning with Codex Alimentarius (32) and the International Commission
on Microbiological Specifications for Food (ICMSF), and continuing with
the National Advisory Committee on Microbiological Criteria for Foods (135),
there has been a movement for many years for more complete safety specifications
for foods in local, national and international trade. The result
is the current emphasis on Hazard Analysis and Critical Control Points
(HACCP) in food production facilities and retail food operations.
However, people have lost sight of the fact that HACCP is only a part of
a company's food production quality management program. A company
cannot accomplish process hazard control until it has process quality control.
Hazards and critical control points can be easily identified. However,
it is a separate issue to actually operate so that there is a very low
chance of process deviation and low risk of a hazardous item being produced.
Critical Concern: without
control, there is life-threatening risk.
Major Concern: a threat
that must be controlled but is not life threatening and requires no government
intervention.
Minor Concern: no threat
to the consumer (normally quality and cleanliness issues).
For example, spoilage bacteria, even at more than 50,000,000 per gram,
are of no known safety concern. Coliform bacteria include both spoilage
and pathogenic microorganisms. Therefore, a coliform count of 1,000
CFU per gram is of minor concern until specified levels of specific pathogens
in the coliform group are established. Only pathogens and pathogenic
substances ingested above threshold levels can cause illness, disease,
and death. Properly controlled levels of salt, sugar, and MSG are
of no concern. Floors, walls, ceilings, and many other items grouped
under Good Manufacturing Practices (31) are really minor concern.
Of minor concern is also the presence of 1,000 Staphylococcus aureus
cells, Bacillus cereus spores, or Clostridium perfringens spores
per gram of food. These organisms are not hazardous until they reach
100,000 vegetative cells per gram. A hazard of critical concern,
on the other hand, is a dose of 1 or more Escherichia coli O157:H7,
100
Salmonella spp., or 500 Campylobacter jejuni in a portion
of hamburger or chicken. It is essential that food be prepared by
a cook who is trained to reduce potential hazards to a safe level.
Even healthy people can become ill if they consume food containing these
pathogens at high enough levels.
Some people develop natural immunity. People who live in an environment
with greater levels of pathogenic agents have a greater tolerance. The
example is farmers who acquire a natural immunity and elevated resistance
to some illnesses after being exposed to many of these pathogens while
working on their farms. It is the job of the cook to make food safe
by washing the food, such as raw fruits and vegetables and by pasteurizing
raw food with the application of heat. During preparation, care must
be taken to prevent cross-contamination of any ready-to-eat foods when
raw foods are handled. (Raw foods include fruits and vegetables as well
as meat, fish, and poultry products.)
Food-related Illness
and Death in the United States
While cooks can control most pathogenic agents in food most of the time,
there are still an enormous number of illnesses and deaths that occur each
year in the U. S because of foodborne agents. More than 200 known
diseases are transmitted through food [Bryan (202); Mead et al. (203)].
The causes of foodborne illness and disease include viruses, bacteria,
parasites, toxins, metals, and prions, and the symptoms of foodborne illness
vary from mild gastroenteritis to life-threatening neurologic, hepatic,
and renal disorders.
Table 1-1
A 1999 Centers for Disease
Control and Prevention report (203) estimated cases of illness and deaths
for the general population in the U.S. due to known causes. (See
Table 1-1.)
By examining Table 1-1,
it can be seen that not all of these pasthogens are transferred by food.
They are sometimes spread by water, person-to-person contact, or
other means. Also note that 67% of the estimated 13.8 million foodborne
illnesses of known etiology are viral (Norwalk-like viruses).
The authors of the 1999
CDC report (203) applied another analysis, taking into account under-reporting
factors, to arrive at an estimate that predicts a much larger annual illness
incidence of 76 million (mostly diarrheal illnesses of 1-to-2-day duration),
325,000 hospitalizations, and 5,000 deaths. This estimate is based
on the authors' further speculation that 80% of the illnesses that occur
annually are due to "unidentified etiological agents".
The CDC report (203) did
not estimate causes of illness or injury due to chemicals, toxins, or hard
foreign objects in food. Predicted annual occurrences cited in Table
1-2 are those estimated by Todd (186).
Government Microbiological
Standards for Raw and Pasteurized Food
The Code of Federal Regulations
[9 CFR §301.2 C] (30) has been interpreted by the United States Department
of Agriculture and the Food and Drug Administration to mean that if a sample
of a processed food is found to be contaminated with E. coli
O157:H7,
Salmonella
spp., or Listeria monocytogenes, the food is deemed unfit for human
consumption. Sample size is variable, often negative in 25 grams,
but the products' microbial standard is not enforced in retail operations,
because retail inspectors seldom check. In retail food operations,
the presence of L. monocytogenes is likely on fresh produce, meat,
fish, and poultry, as well as on floors and in floor drains. It has
been estimated by Farber (48) that raw food (e.g., coleslaw) can contain
100 to 10,000 CFU/g of L. monocytogenes. Meat products will
have low levels of
E. coli O157:H7 and Salmonella spp., and
poultry is often found to be contaminated with Campylobacter jejuni
and Salmonella spp.
Need for International
Safe and Hazardous Level Guidelines
At the present time, there
are few worldwide food safety guidelines for upper or lower control limits
of potential hazards in foods, or the process limits. This document
proposes limits. When standards do exist, they may be inappropriate
(e.g., specification of the numbers of coliforms in milk and in shellfish
waters), or they may be unattainable (e.g., a zero level of both Salmonella
spp. and L. monocytogenes in food). There is no zero level
in food safety. There is a point at which measurements cannot be
made with any degree of statistical reliability, and this point is frequently
taken as "zero." For example, processed food is assumed to be safe
from salmonellae contamination if there are no detectable salmonellae in
a sample using the method of analysis described by the Bacteriological
Analytical Manual (54). However, as laboratory methods improve, standards
for safe levels of pathogenic material in food may be established.
When safety standards or guidelines are developed for microbiological,
chemical, and physical hazards in food, the standards or guidelines must
be based on the risk of causing injury or illness to consumers, not what
the processing industry is capable of achieving, or what scientific technology
is capable of measuring.
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A)
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Contents
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