| How do parents make life safer and healthier for their kids? One of the ways is to impose limits on things like roaming distance within the neighborhood, curfews, and insisting that you eat your vegetables. Just common sense, right? Let’s take a look at some more of it.
Limits are also necessary within the food manufacturing industry. Let’s take a look at Hazard Analysis and Critical Control Point (HACCP) Principle No. 3 to see how they’re established and why.
Principle 3: Establish critical limits for each critical control point. – You can think of a critical limit as a boundary of safety for each critical control point (CCP). So how do you determine that boundary of safety? It’s difficult to generalize, but if you’ve ever watched the TV show Hoarders, you have an excellent example of one that has not only been breeched, but torn asunder.
In order to prevent things in the commercial food industry from getting anywhere near Hoarders bad, maximum and minimum values are set in place, representing safeguards to physical, biological, and chemical parameters at play within the industry. Critical limits can be obtained from regulatory standards and guidelines, scientific literature, experimental studies, as well as information provided by consultants. These critical limits come into play with issues as varied as machine design, raw material temperatures, and overall safe processing times.
How could the hoarders let things get so bad? If you listen carefully, you’ll hear bits of information that provide a clue. They’ll say it started with a few things falling to the floor which they didn’t feel like picking up and it escalated from there.
Now all of us live within environments which differ as to their cleanliness, but by and large we live within space where we feel comfortable and consider to be reasonably clean. We don’t all habitually move stoves and refrigerators to clean, for example. But if we were so inclined, refrigerators do come with front access panels that are easily removed. Trouble is the space they provide access to often isn’t large enough to accommodate hands and a vacuum cleaner nozzle comfortably. You can imagine how frustrating and potentially dangerous it would be to public health to have commercial machinery that provided such limited access for cleaning.
To cope with this problem design engineers institute minimum and maximum parameters, such as in the critical limit dimensions of a removable cover. Their guideline would ensure that enough space is provided so that personnel can fully access all aspects of machinery with tools for cleaning. That same cover can also have established maximum critical limits, so that dimensions aren’t too large and heavy to be manipulated by hand. Human nature being what it is, something that is too difficult to remove may be “forgotten” and parts of the machine may never get cleaned.
Raw meats and many produce can contain hazards like salmonella, E. coli, and other nasty critters that are dangerous to human health. One of the ways the commercial food industry works to ensure that these contaminants aren’t unleashed on the public is to install programmable control systems into processing machinery that essentially cooks the meat at an established minimum temperature for a minimum amount of time. Utilizing this type of temperature control in conjunction with an established maximum cooking parameter for temperature and time will virtually eliminate the possibility of overcooked or burnt food products. When you buy that frozen dinner in most cases it’s completely cooked, but it’s a rarity to find it’s been burned.
Another situation in which critical limits are utilized is in the maintenance of machinery, such as when they limit the number of hours a machine can be operated before it is shut down for servicing.
Next week we’ll move on to Principle No. 4 and see how it establishes monitoring requirements for each CCP. ____________________________________________
Archive for October, 2011
| What would you do if you heard an unfamiliar sound coming from your water heater? If you’re like most people you’d make a mental note to keep an eye on it, but ignore it for the most part. Unfortunately, this less than proactive approach often results in water heater floods. As an engineer, I’m more likely than the general population to investigate the cause of the water heater’s sound and proactively seek a remedy before a real problem has a chance to develop.
The FDA’s Hazard Analysis Critical Control Point (HACCP) seeks to accomplish the same with regard to food production. As discussed last week with regard to HACCP Principle 1, those involved in designing food processing equipment must proactively analyze designs to identify potential food safety hazards. Now let’s see how common sense is once again employed through Principle 2, guiding design engineers to take control of situations where hazards have been identified through Principle 1.
HACCP Principle 2: Identify critical control points. A critical control point (CCP) is a step in the design process at which a control can be most effectively introduced to prevent or eliminate hazards. In this context a “control” would be a design revision to eliminate hazards identified during the Principle 1 stage. We will once again use the two examples introduced in last week’s blog discussion on Principle 1.
In our first example, hazard analysis revealed that food can accumulate in a food processing machine in areas where cleaning is difficult or impossible. This accumulation would eventually rot and fall into uncontaminated food passing through production lines. Design engineers would work to address this contamination hazard by identifying a CCP within the design process, that is, the best place where a preventative measure can be added to the machine setup to facilitate removal of the accumulation. At that CCP, measures can be taken to change the machine’s design. Perhaps all that is needed to correct the situation is to include easy to remove access covers.
In our second example hazard analysis revealed that the metal tooling as designed for our food production machine was too fragile and would not withstand the repeated forces imposed on it by the mass production process. This design flaw presents a strong possibility that metal parts will break off and enter food on the line. To correct this situation, design engineers must once again identify the juncture within the design process at which a CCP is identified. There, a preventative measure can most effectively be introduced, enabling more robust metal to be used in the tooling.
The previous two examples illustrate CCPs being utilized within the design process. CCPs can also be introduced outside the design process, as when they are identified during the course of training procedures involving the operation, cleaning, and general maintenance of equipment and production lines. And an excellent way of implementing this approach is to have design engineers collaborate with operating and maintenance staff. Working together, they are best able to identify key elements to be addressed and make note of them within written procedures.
Now that we have identified some examples of CCPs within the design process, we can move on to HACCP Principle 3 and how it guides design engineers to establish critical limits for each CCP.
| Imagine a doctor not washing his hands in between baby deliveries. Unbelievable but true, this was a widespread practice up until last century when infections, followed by death of newborns, was an all-too common occurrence in hospitals across the United States. It took an observant nurse to put two and two together after watching many physicians go from delivery room to delivery room, mother to mother, without washing their hands. Once hand washing in between deliveries was made mandatory, the incidence of infection and death in newborns plummeted.
Why wasn’t this simple and common sense solution instituted earlier? Was it ignorance, negligence, laziness, or a combination thereof that kept doctors from washing up? Whatever the root cause of this ridiculous oversight, it remains a fact of history. Common sense was finally employed, and babies’ lives saved.
The same common sense is at play in the development of the FDA’s Hazard Analysis Critical Control Point (HACCP) policy, which was developed to ensure the safe production of commercial food products. Like the observant nurse who played watchdog to doctors’ poor hygiene practices and became the catalyst for improved hospital procedures set in place and remaining until today, HACCP policy results in a proactive strategy where hazards are identified, assessed, and then control measures developed to prevent, reduce, and eliminate potential hazards.
In this article, we’ll begin to explore how engineers design food processing equipment and production lines in accordance with the seven HACCP principles. You will note that here, once again, the execution of common sense can solve many problems.
Principle 1: Conduct a hazard analysis. – Those involved in designing food processing equipment and production lines must proactively analyze designs to identify potential food safety hazards. If the hazard analysis reveals contaminants are likely to find their way into food products, then preventive measures are put in place in the form of design revisions.
For example, suppose a food processing machine is designed and hazard analysis reveals that food can accumulate in areas where cleaning is difficult or impossible. This accumulation will rot with time, and the bacteria-laden glop can fall onto uncontaminated food passing through production lines.
As another example, a piece of metal tooling may have been designed with the intent to form food products into a certain shape, but hazard analysis reveals that the tooling is too fragile and cannot withstand the repeated forces imposed on it by the mass production process. There is a strong likelihood that small metal parts can break off and enter the food on the line.
Next time we’ll move on to HACCP Principle 2 and see how design engineers control problems identified during the hazard analysis performed pursuant to Principle 1.
| Perhaps you’ve heard of the non-reciprocal wine and sewage principle. I’m not sure where it originated, but it states that if you add a cup of wine to a barrel of sewage, you still get a barrel of sewage. No brainer, right? Well, consider the flip side. If you add a cup of sewage to a barrel of wine, you also get nothing more than a barrel of sewage. In other words, a small amount of contamination goes a long way.
The premise of this principle also applies within the food manufacturing industry. If you were to add uncontaminated food to garbage, you would just get more garbage, and if you add garbage to food… well, you get it. The term garbage can encompass an endless variety of contaminants, such as broken glass, metal shavings, nuts, bolts, plastic fibers, grease, broken machine parts, errant human body parts, and on and on. Although the FDA does allow for certain levels of natural contaminants, like insect parts and rodent hairs, consumers are never pleased when undesirable elements enter their food supply. It could even be dangerous.
When design engineers create food processing machinery and production lines, they must be on the lookout for potential risks of contamination hazards. They must also provide a quick means of mitigation, before contaminants can enter into commercial production. A systematic approach provides the best means of addressing these needs, allowing for a pre-emptive method to ensure food safety. Checklists and procedural policy set in place for these reasons will enable design engineers to identify, assess, and control risks before they turn into hazards. This is where Hazard Analysis Critical Control Point (HACCP) planning comes in.
To address these needs, the FDA has set up the HACCP (pronounced, “hass-up”) system, defined as “…a management system in which food safety is addressed through the analysis and control of biological, chemical, and physical hazards from raw material production, procurement and handling, to manufacturing, distribution and consumption of the finished product.”
HACCP is the outgrowth of FDA current Good Manufacturing Practices (cGMP), which are set out in the Code of Federal Regulations pertaining to commercial food processors and manufacturers, Title 21, Part 110, entitled, “current Good Manufacturing Practice in Manufacturing, Packing or Holding Human Food.” Every commercial food processor, regardless of size, must implement a cGMP/HACCP quality assurance program to comply with these regulations.
HACCP is a proactive strategy where hazards are identified, assessed, and then control measures developed to prevent, reduce, or eliminate potential hazards. A key element of HACCP involves prevention of food contamination during all phases of manufacturing, and way before the finished food product undergoes quality inspection. This strategy extends into the food manufacturing equipment and production line design process as well.
Next time we’ll continue our look at HACCP and how its seven principles are used by design engineers to prevent food product contamination.
| My wife and I have an agreement concerning the kitchen. She cooks, I clean. Plates and utensils are easy enough to deal with, especially when you have a dishwasher. Pots and pans are a little more challenging. But what I hate the most are the food processors, mixers, blenders, slicers and dicers. They’re designed to make food preparation easier and less time consuming, but they sure don’t make the clean up any easier! Quite frankly, I suspect the time involved to clean them exceeds the time saved in food preparation.
Food processors on a larger scale are also used to manufacture many food products in manufacturing facilities, and being larger and more complicated overall, they’re even more difficult to clean. For example, I once designed a production line incorporating a dough mixer for one of the largest wholesale bakery product suppliers in the United States. A small elevator was required to lift vast amounts of ingredients into a mixing bowl the size of a compact car. Its mixing arms were so heavy, two people were required to lift them into position. It was also my task to ensure that the equipment as designed was capable of being thoroughly cleaned in a timely and cost effective manner.
Food processing machinery must be designed so that all areas coming into contact with ingredients can be readily accessed for cleaning. And since most of the equipment you are dealing with in this setting is far too cumbersome to be portable, the majority of the cleaning must be cleaned in place, known in the industry as CIP. To facilitate CIP, commercial machinery is designed with hatches and special covers that allow workers to get inside with their cleaning equipment. Small, portable parts of the machine, such as pipes, cutting blades, forming mechanisms, and extrusion dies, are often made to be removable so that they can be carried over to an industrial sized sink for cleaning out of place, or COP. These potable machine components are typically removable for COP without the use of any tools and are fitted with flip latches, spring clips, and thumb screws to facilitate the process.
Everything in a food manufacturing facility, from production machinery to conveyor belts, is typically cleaned with hot, pressurized water. The water is ejected from the nozzle end of a hose hooked up to a specially designed valve that mixes steam and cold water. The result is scalding hot pressurized water that easily dislodges food residues. Bacteria doesn’t stand a chance against this barrage. The water, which is maintained at about 180°F, quickly sterilizes everything it makes contact with. It also provides a chemical-free clean that won’t leave behind residues. Once dislodged, debris is flushed out through strategically placed openings in the machine which then empty into nearby floor drains.
As a consequence of the frequent cleanings commercial food preparation machinery requires, their parts must be able to withstand frequent exposure to high pressure water streams. Parts are typically constructed of ultra high molecular weight (UHMW) food-grade plastics and metal alloys such as stainless steels, capable of withstanding the corrosive effects of water. And since water and electricity make a dangerous combination, gaskets and seals on the equipment must be tight enough to protect against water making its way into motors and other electrical parts.
Next time we’ll look at how design engineers of food manufacturing equipment use a systematic approach to minimize the possibility of food safety hazards, such as product contamination.