Our piece, Trevor Suslow Of UC Davis Speaks Out: The Truth About Consumer Reports, Bacteria And Packaged Leafy Greens, was widely circulated. In fact, the American Council On Science and Health, which we wrote about here, picked up on the piece in its ACSH Morning Dispatch:
Consumers Union: Go Back to Burgers
Jim Prevor’s Perishable Pundit blog points out the “lack of sophistication with which Consumers Union approaches the science” in their recent revelation that packaged salad can contain bacteria.
“Sure, Consumers Union is very good at finding bacteria; there’s bacteria everywhere that won’t necessarily make us sick,” says Stier. “It’s unfortunate that people are being scared away from healthy, conveniently packaged vegetables at a time that our country is so concerned about dealing with obesity. Here the vegetable producers and marketers have offered a valuable tool to make vegetables more available, and the scar-mongers at Consumers Union are trying to alarm us about something on unscientific grounds. It’s basically an effort to further a legislative goal of more food safety regulation.”
Dr. Ross adds, “Foodborne illness is a problem, but pointing out how many leafy vegetables have coliform bacteria on them does not add to the discussion about food safety.”
We also received dozens and dozens of responses on this piece. A number were simply polite expressions of appreciation as so many media outlets publicized Consumer Report’s piece without any real thought about what it meant:
Thank you for printing Dr. Trevor Suslow’s response to the Consumer Reports article.
Many of the letters, though, we wouldn’t even consider publishing because they were nothing but anonymous ad hominem attacks on Dr. Suslow. In other words, instead of attacking any particular argument Dr. Suslow made, people decided to call him names.
Of course, some of the letters sought additional information, and Dr. Suslow was kind enough to provide some amplification on a main topic of interest — the intersection between consumer behavior and packaged salad quality and safety:
Comments regarding cold-chain management, product temperature at point of purchase (POP), and the role of the home consumer in handling of packaged salads have prompted additional requests for information. Two main questions regarding consumer recommendations emerged:
1. Is post-purchase temperature equally relevant for quality and safety?
2. Can consumers really judge if product has been temperature-compromised at POP?
Simple answers to the theme of Question #1 are not possible because exceptions to lower risk or higher risk can always be made and are equally valid.
The most responsible answer is “It depends.” However this is unsatisfactory, especially when trying to provide information consumers can use as an everyday rule of thumb. So I will make a brief general attempt and hope any backlash is not too intense. To limit the scope of the response, I will stick with packaged salads for the most part.
Is post-purchase temperature equally relevant for quality and safety?
Temperature management and cumulative cold-chain history are predominantly quality issues and determine a product’s visual, sensory, and nutritive keeping-potential. The FDA Food Code (2009) has identified Time/Temperature Control for Safety (TCS) limits, at or below 41F (5C), for certain value-added produce that must be applied to distribution, storage, and display. This includes cut leafy greens as well as fresh-cut cantaloupe, pre-sliced or diced tomatoes. These are designated as TCS foods due to recurring outbreaks AND the known growth potential of bacterial pathogens on the product.
The recognized low infectious dose of many pathogens may be sufficient to cause illness in highly susceptible individuals, and growth on the product is not necessary to cause great harm. However, not all possible pathogens and variants of these pathogens, which may infrequently find their way onto or into product, are equally infectious to all individuals.
Proper post-purchase temperature management may, and likely will, keep a bacterial contaminant, such as Salmonella or pathogenic E. coli, below the threshold for illness for an individual consumer. Improper post-purchase temperature management may, and likely will, contribute to elevating these pathogens above an individual’s personal threshold and, by cross-contamination in serving, increase the chance of exposure in an individual portion from the same bag.
The absence of visual signs of improper temperature exposure, such as spoilage or decay, provides no assurance that significant growth of bacterial pathogens has not occurred. Recent research evidence suggests that the pre-consumption environment may increase the aggressiveness (lowering the threshold) by activating mechanisms for human infection. In summary, with all best efforts at prevention and control, if pathogens are present in packaged salads, the consumer is at risk of illness, possible long-term health effects, and death.
Keeping packaged salads cold is essential to quality and may reduce risk to individual consumers, though not likely all consumers of the same lot.
Can consumers really judge if product has been temperature-compromised at POP?
Yes and No. I’ll bet you knew that was coming. Realistically the Yes is very small and No the more sensible response. So to keep this answer simple for a change, let’s stick with the No side of the equation and talk briefly about a potential consumer-oriented solution that always crops up following media coverage of high counts of bacteria on packaged salads.
Time:Temperature Indicators or Integrators (TTI) have been around for a long time and are used on many perishable products. The function of a TTI is to make improper and abusive temperature exposure, linked to known quality defect-inducing conditions, readily apparent by a simply visual inspection, usually a color change, color development (invisible to highly visible), or progressive loss of color bars on a small patch or tag. No equipment is needed and no special training is required for anyone to get the information.
Photo courtesy of Cold Chain Technologies
There are many types and there have been many improvements in accuracy and readability over the past 15 years. For the consumer, TTI’s affixed to a bag, clamshell, or other individualized purchase unit would be the relevant location. These have been used in the EU for many years, including on value-added produce. There are many arguments for and against the value of TTI labeling, which is beyond the details of this response; retailers in the U.S. have consistently argued against their use.
Do TTI’s tell the consumer anything about product safety? Not really, apart from considerations for TCS in the answer to Question #1 above. If the TTI validations, and therefore the rate of color-change, were adjusted to pathogen growth response rather than quality loss and shelf-life parameters, it could be argued that a level of consumer protection had been achieved. Under the current boundaries at the low end of cold-chain performance, would safe product be destroyed? Highly likely.
Could TTI’s help simplify a consumer’s POP decision about quality? I think so.
Would the use of TTI complicate a retailer’s liability? I will let the experts answer that.
We thank Dr. Suslow for these thoughtful responses.
To us, both questions addressed by Dr. Suslow illustrate how a supposedly consumer-friendly change can turn out to be anti-consumer.
Traditionally there was a negligence standard for product sales, and so a manufacturer — including a producer of food — could only be held liable if the company was negligent or violated an implied warranty. Then in 1963 a unanimous Supreme Court of California handed down a decision in the famous Greenman v Yuba Power Products, Inc., which held that a “manufacturer is strictly liable in tort when an article he places on the market, knowing that it is to be used without inspection for defects, proves to have a defect that causes injury to a human being.”
When it comes to food safety, this means that the producer of a food is typically the one responsible if there is a food safety problem. However, a retailer selling the item can be held liable, but this is typically only secondary liability that comes into play if a producer is insolvent. This explains why retailers are very rigorous on making sure producers have liability insurance.
This legal standard means that many food safety measures that might otherwise be taken are not. In a negligence-based legal environment, producers of the products Dr. Suslow mentions — “cut leafy greens as well as fresh cut cantaloupe, pre-sliced or diced tomatoes” — might well have warning labels on the products advising consumers they should not be left in hot cars, not be left out of refrigeration, etc. — because under a negligence standard, the producers would want to establish that they warned consumers. They would want to establish that the consumers, rather than the producers, were negligent for not following instructions. But under a standard of “Strict liability,” the producer is equally liable with or without the warnings — so why depress sales with lots of warnings.
The same goes with retailers. They could insist on sending consumers home with all TCS foods in an insulated bag or cooler to keep them cool. It is, however, an added complication and expense, and the retailers are not liable so doing so doesn’t decrease their liability.
The Time:Tempertaure Indicators (TTI’s) do pose a more interesting legal question. On the trade side, selling a product that was indicating it had been exposed to temperature abuse or was in the system too long would seem to create the opportunity for a producer to sue a retailer if a producer was ever held liable for a food safety problem on product that had been sold despite a warning on the package.
There is even an issue as to whether such a device would transform a product from one that is expected to be “used without inspection” into one that consumers could be legally expected to inspect. Although in the spinach crisis, there was a lot of evidence that people who got sick had consumed product after its “best if used by” date, and that didn’t seem to limit liability — although “best if used by” is not the same as an advisory “ do not consume” after a given date.
Of course, whatever the state of liability law, many producers and retailers would insist on such things as Dr. Suslow discusses if they thought it would solve a real problem that was hurting people. The frequency of known illness is so slight from these products that adding a highly imperfect screen such as warning labels or Time:Temperature devices can be expected, at enormous cost, to have indecipherable effects on the frequency of foodborne illness related to these products.
…Which doesn’t mean the industry shouldn’t look at some of these things more closely. For the most part, these are quality issues more than food safety issues. We remember Frieda Caplan chastising the apple growers in the state of Washington at a speech before a Washington Apple Commission event that must have been two decades ago.
She pointed out that the growers and packers spent millions to immediately cool and refrigerate the apples during storage. She reminded them that they used expensive reefer trucks to transport the apples, that the supermarket chains would store the apples in expensive refrigerated warehouses and deliver them to each store in a refrigerated truck but then, to get added shelf space in a store, the apple shippers would encourage retailers to give them a big dry table at the front for apple display.
She asked if all that investment in refrigeration didn’t prove that the growers and shippers thought it very important, and wasn’t the willingness to be displayed on a dry table a deal with the devil — a short-term sales boost weighed against a longer term decline as consumers got apples in poorer condition and thus were less satisfied with their purchases?
Papa Pundit was for a long time a major exporter of iceberg lettuce to Europe. Back in those days, lettuce was shipped by truck to New York and then transferred to an ocean-going vessel for delivery. We learned how even minor temperature changes could affect the life of the product. In addition to a physical inspection in New York, the old tape from the Ryan temperature recorder was carefully reviewed after the cross-country journey. We learned, with very expensive lessons, that if on the cross-country trip the temperature rose over our specified range, even for a day, the lettuce, though looking perfect in New York, would not make a good arrival in Europe.
We paid attention to that because it would cost us a lot of money if we didn’t — and we knew it. It is hard to get shippers or retailers to pay attention to the fact that consumers may not be getting the shelf life or flavor in their kitchens that they would like to because there were temperature deviations somewhere in the chain — maybe in the consumer’s car ride home — or because the consumer held the product too long.
Warning labels, insulated bags, Time:Temperature devices… all would help with these quality issues but, to date at least, producers and retailers alike generally judge the payoff as too diffused and too little to make the investment worthwhile. We doubt this Consumer Reports article will change that verdict.
Once again, thanks to Dr. Trevor Suslow of UC Davis for helping the industry analyze this important issue.