5 replies to this topic

[EEsterling]

Greetings,

I am glad to have found this forum because I have had some difficulty finding clear answers for with some grey areas of food safety. I appreciate the opportunity to ask some questions of you experts.

Background: I am an registered dietitian with a ServSafe certification which I think provides rudimentary food safety knowledge, but no where near the extent demonstrated on this forum. My specific concern is with a food program in the US called Meals on Wheels where we bring home delivered food to the homes of the elderly. There are some areas which I know we need to address to provide safer food to avoid time-temperature abuse. But I am hoping to get some input on some grey areas to help prioritize the issues we address.

The life of food from our point of view is: a) foods are prepared at a caterer; chilled and plated and refrigerated overnight. The plating is not special packaging such as reduced oxygen. b) delivered in chillers to several sites of our organization. c) delivered by our staff to individual homes. Our temperature problems begin from the time the food reaches our sites until it reaches the homes of consumers.

At this time my question is "Potentially Hazardous Food (PHF) or not?"

The 2009 US Food Code defines PHF (aka Time/Temperature Control for Safety Food):

Animal food that is raw or heat-treated; a plant food that is heat treated or consists of raw seed sprouts, cut melons, cut leafy greens, cut tomatoes or mixtures of cut tomatoes that are not modified in a way so that they are unable to support pathogenic microorganism growth or toxin formation, or garlic-in-oil mixtures that are not modified in a way so that they are unable to support pathogenic microorganism growth or toxin formation.

There are also tables of pH and water activity.

Food of Concern #1: Canned fruit which is removed from the can and individually cupped.

My thought: for the canned fruits we use (peaches, apricots, fruit cup, pears, pineapple), non-PHF because they are not heat treated and the pH is generally below 4.2.

Food of Concern #2: Frozen vegetables (generally carrot coins, green beans, corn, lima beans, peas, broccoli, and spinach) which are parboiled, then plated and chilled, delivered to consumer homes chilled to be heated by the consumer.

My thought from ServSafe training was non-PHF. However, I now question that because of the US Food Code statement "plant food that is heat treated." I think this means all of our cooked vegetables must be considered PHF (unless they are very low pH, but I don't see any that are). On the other hand, I have a hard time being equally concerned with green beans as I am with meatloaf.

Finally, I interpret the "cut leafy greens, cut tomatoes" clause as meaning fresh cut leafy greens and fresh cut tomatoes. Are commercially processed spinach or diced tomatoes included in that explicit clause per the US Food Code, or am I correct in inserting "fresh cut" and therefore they are not automatically part in the PHF category? In other words, I consider salads and tomato slices to be PHF, but I am not sure about frozen spinach and canned diced tomatoes.

Thank you so much for your responses.

[Charles.C]

Dear EESterling,

Interesting post.

I'm not in the (loc./fed legislative) USA so these thoughts should be regarded as speculative.

The subject of PHF is obviously complex (your quoted extract seems to be only a very, very, small part of the relevant content in Food Code 2009 ).

Some idea of the geographical complexity here -

http://www.fda.gov/F...s/ucm094143.htm
(dd 2001 but apparently "updated" to 2011 )

To illustrate some idea of the USA complexity people can see pgs 15 et seq and 317 et seq of attachment below.

 us fda Food code 2009.pdf   2.3MB   49 downloads

and -

http://www.fda.gov/F...s/ucm111167.htm

http://www.fda.gov/F...s/ucm094141.htm

aw values are relevant. Offhand, as currently described in yr post, i suspect all yr examples other than the (packaged) canned food are (via Food Code 2009 et al) PHF (or potentially PHF) for various reasons.

Rds / Charles.C

added - this Australian analysis is also very useful / readable IMO -

 new south wales - potentially-hazardous-foods.pdf   143.27KB   52 downloads

added (2) -

these 4 items/viewpoints may further assist with #1 and (maybe) #2 (though it should be noted that no specific aw data is discussed)

http://www.foodsafet.../FAQcannedfruit

http://en.allexperts...anned-foods.htm

 potentially hazardous foods - menu & recipes.doc   210.5KB   32 downloads

 pack_safe_lunch_294.pdf   39.14KB   25 downloads
("However, once the package is opened, the foods become potentially hazardous and should be eaten or refrigerated promptly.")

[EEsterling]

Thank you so much for your response Charles.

Especially:
http://www.foodsafet.../FAQcannedfruit
Which directly addresses my canned fruit question, happily with the same conclusion I came to.

Also, on the same web site, people learning about PHF might enjoy the "Potentially Hazardous Food or Not" activity in the first slide presentation on this page:
http://www.foodsafet...r/managers.html

Based on several of the sources that you linked to, I am now convinced that I need to treat all cooked vegetables and all greens and cut tomatoes (cooked or not, regardless of who cut them where or under what circumstances) need to be treated as time-temperature sensitive PHF.

Thanks again.
-Eric

[Charles.C]

Dear EEsterling,

Thks for pointing out the extra link. Very nice presentation although, probably inevitably, I noticed one example, “cake”, where the non-phf tag is debated elsewhere (numerical aw values/types of cream).

This whole (phf) area is obviously a bit of a minefield. Maybe the reason that some areas, eg EC, seem to hv avoided it.

Another interesting corollary is whether all “non- phf" are (in HACCP terminology) not (significantly?) hazardous, or, perhaps equivalently, “low risk”. It depends on the definitions again of course.

I quite liked this discussion of some possible (and significant) limitations of their own definition in the Australian Safe Foods Standard (2001) (partially re-appearing in the (2008) NSW pdf attached previously).

Potentially hazardous food means food that has to be kept at certain temperatures to minimise the growth of any pathogenic micro-organisms that may be present in thefood or to prevent the formation of toxins in the food.
‘Potentially hazardous food’ must meet certain temperature requirements. Thisdefinition clarifies that the only food that must comply with these temperaturerequirements is food that must be kept at these temperatures to minimise the growth of food-borne pathogens.

What food is potentially hazardous?

For the purposes of Standard 3.2.2, food that meets both of the following criteria is considered potentially hazardous:
• the food may contain a pathogen that needs to multiply in order to cause illness;
And
• the food will support the growth of this pathogen.

Food that must be kept under temperature control to prevent toxins forming as a result of bacterial decomposition is also considered potentially hazardous. For example, certain species of fish need to be rapidly chilled shortly after capture to minimise the formation of histamine. This toxin is formed when certain species of bacteria are allowed to multiply and break down the flesh of the fish. However, minimising the growth of the bacteria that causes this spoilage can prevent the toxin from forming. The food is potentially hazardous only because the food has the potential to cause illness. The food is likely to become unsafe if it is not kept under temperature control.

The following foods are examples of foods that are normally potentially hazardous:
• raw and cooked meat or foods containing raw or cooked meat, for example casseroles, curries, lasagne and meat pies;
• dairy products and foods containing dairy products, for example milk, custard and
dairy-based desserts;
• seafood (excluding live seafood) and foods containing seafood;
• processed fruits and vegetables, for example salads and unpasteurised juices;
• cooked rice and pasta;
• processed foods containing eggs, beans, nuts or other protein-rich food, for example quiche and soya bean products; and
• foods that contain any of the above foods, for example sandwiches and quiches.

Note that some of the above types of food will not be potentially hazardous because they have been manufactured to ensure they are not potentially hazardous. However, they will still require refrigeration for food quality reasons. If it is uncertain whether a manufactured food is potentially hazardous, advice should be sought from the manufacturer.

What food is not potentially hazardous?

Many foods do not rely on temperature control for safety because they have been processed to ensure that pathogens are not present in the food or the food is not able to support the growth of food-borne pathogens. These foods are not considered potentially hazardous. Food manufacturers usually achieve food safety by one of the following methods:
• destroying any pathogens that may be present in the food and then packaging the food in a hermetically sealed container so that the food cannot be contaminated, for example canned and bottled food;
• creating an environment in the food that does not support the growth of food-borne pathogens. This is usually done by making the food too acidic for pathogen growth, reducing the available water in the food by drying the food and/or adding salt and sugar, using food additives that inhibit bacterial growth, or a combination of these things, for example dried fruit, salted dried meats and fermented dried
meats; or
• destroying or reducing the number of pathogens in the food and creating an environment that will minimise or prevent the growth of any pathogens that are still present and could multiply in the food, for example yoghurts, cheeses, spreads, sauces, dried pasta, pasteurised juices, breads, dried milk and dried
custard powder.

Although the above foods are not considered potentially hazardous, they may become potentially hazardous when the food is opened or altered in some way. For example, a canned beef stew should be considered potentially hazardous once it is opened and custard powder should be considered potentially hazardous when it is reconstituted.

Many raw unprocessed or semi-processed foods are also not potentially hazardous because they either do not support the growth of food-borne pathogens or do not contain food-borne pathogens. Examples of foods that do not support the growth of food-borne pathogens are raw whole fruits and vegetables, uncooked rice, flour and sugar. Examples of foods that would not normally contain food-borne pathogens are nuts in the shell and whole uncracked hens’ eggs.

Food-borne pathogens that do not need to multiply or do not need to multiply to large numbers in food to cause illness

This standard requires potentially hazardous food to be kept under temperature control to minimise the growth of food-borne pathogens. However, not all food-borne pathogens need to multiply in food to cause illness. Examples of pathogens that cause illness when in low numbers are viruses (for example hepatitis A and the Norwalk virus), enterohaemorrhagic strains of Escherichia coli (for example E. coli O157 and O111), Campylobacter jejuni and Shigella spp. If a ready-to-eat food is contaminated with low numbers of one of these pathogens, illness may occur. Food must be protected from contamination to prevent one of these pathogens being present. Once a food contains low numbers of one of these pathogens, keeping the food under temperature control will not make the food any more or less safe. Therefore, a ready-to-eat food that contains, for example, hepatitis A is considered a contaminated food that is unsafe. It is not considered a potentially hazardous food.
In certain circumstances the food-borne pathogens Salmonella spp., Listeria monocytogenes, Vibrio vulnificus and Vibrio cholerae may also cause illness when they are present in small numbers. The circumstances include, in the case of Salmonella spp., the strain of the pathogen and, in the case of all the pathogens, the type of food in which the pathogen is present. The person who consumes the food may also play a part: persons who are young, elderly or have suppressed immune systems, or women who are pregnant are more susceptible to food-borne illness and low numbers of these pathogens can cause illness in these persons. However, if these pathogens are present in a food that supports their growth, the food should be considered potentially hazardous. If they are present in ready-to-eat food that does not support their growth, the food may still cause illness but would not be potentially hazardous.

 Safe Food Australia (2001).pdf   736.33KB   34 downloads

Rgds / Charles.C

[Markcra]

Hi - This guide may also be helpful if I can upload it.

 guidelines for food service to vulnerable persons.pdf   261.98KB   33 downloads

[EEsterling]

> This whole (phf) area is obviously a bit of a minefield.

Definitely. And it isn't helped by vague assertions such as from your quote from the Australian standards:

processed fruits and vegetables, for example salads and unpasteurised juices;

"Processed" is such an all encompassing term. But surely not all processing incurs the same increase in risk.

Indeed from the PDF that Markcra posted, here is one definition:

Process means, in relation to food, an activity conducted to prepare food for sale including chopping, cooking, drying, fermenting, heating, pasteurising, thawing and washing, or a combination of these activities.

So, using that definition leads to the very counter intuitive conclusion that washed, pasteurized, and/or dehydrated* green beans are a greater potential hazard than raw unwashed green beans.

But I'm still trying to get my head around treating all cooked vegetables with the same deference of meatloaf and poultry.

* I'm extrapolating "drying" to the extreme of dehydrated. While I don't believe dehydrated food is PHF because of the low Aw, one would need to ask the question based on the above to quotes. I brought it up to reiterate the minefield nature of the question of "what is PHF?"