Heavy Metals in Pet Food: Changes in toxin levels over the past decade

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Hosted by: Patricia Atkins – R&D and NPD Chemist  |   Alan H. Katz, PhD – Vice President of Chemical Manufacturing  |   Eric Smith - Applications Scientist

Time: 35-mins presentation, 25-mins Q&A: 60-mins total show time

In this webinar you will:

  • Learn about the business and processes involved in commercial pet food manufacturing and how it can lead to mass contamination issues
  • Understand the history and content of US food safety regulations as they have pertained to pet food in the past and under current guidelines
  • Discover the meaning of ingredients in pet food & the level of contamination found in 2009 and in 2019
  • Learn about research practices and protocols used to accurately detect and analyse toxin levels in pet food

Over the years, pets have evolved to an integral part of families all over the world and therefore, it is no surprise that pet food has become a multi-billion-dollar business, with dynamic growth. However, the industry is not free of controversy; after the melamine scare of 2007, the potential for contaminants in pet food came to public attention.

Ten years ago, in 2009, SPEX CertiPrep, conducted a study on commercially available pet food, including popular brands sold across a range of retail prices; investigating the levels of heavy metals and other potentially toxic elements. Many of the samples showed significant concentrations of various toxic metals. In several cases, the concentrations exceeded the extrapolated human limit values calculated to pet-size dosages.

Heavy metals are a threat to human and animal health as well as the environment. Testing for regulatory limits for toxic compounds is an established practice in many consumer industries; testing for toxic and heavy metals is a common process in quality control, analytical and consumer safety labs. In the world of food safety, the control of harmful substances is now governed under the Food Safety Modernization Act (FSMA).

In 2011, when the FSMA was enacted, pet food was included under its umbrella. In 2019, SPEX CertiPrep revisited toxin levels in pet food in a new study, looking at existing and new brands that had emerged over the last decade, to see if heavy metal contamination had changed over the past decade or since the enactment of the law.

Pets are an integral part of millions of families across the world and unlike many other types of animal feed, pet food is stored within our homes and handled by all members of our families. Whether you are involved in quality control, safety testing, research, or you are simply a concerned pet owner, you understand the importance of ensuring safe pet food for all.

Meet the scientific expert presenters from SPEX:

Your hosts for this webinar

Patricia Atkins – Senior Applications Scientist at SPEX® CertiPrep
Patricia graduated from Rutgers University in NJ and started her career as a laboratory supervisor for Ciba Specialty Chemicals. In 2008, Patricia joined SPEX® CertiPrep within their Certified Reference Material’s division. As a senior application scientist, she spends much of her time researching industry trends and developing new reference materials.  She is an experienced speaker and has presented at numerous conferences, including NACRW, NEMC, Pittcon and AOAC. She is also a published author and her work has appeared in various journals and trade publications, including Spectroscopy, LCGC and Cannabis Science and Technology, where she is a columnist for analytical issues in cannabis testing.

Dr. Alan H. Katz, Ph.D. - Vice President of Chemical Manufacturing at SPEX® CertiPrep
Alan holds a B.A. in Chemistry from the University at Buffalo and a Ph.D. from Princeton University. His specialties include organic, computational, heterocyclic, and synthetic chemistry, drug discovery, biological assay design, structure-based molecular modeling, and lab automation. He has enjoyed combining his expertise with his interest in computer programming to develop a system to assist in drug discovery. At SPEX® CertiPrep, he oversees the manufacturing and quality control of certified chemical reference materials, including inorganic and organic chemical standards, NPD and R&D.

Eric Smith - Applications Scientist at SPEX® SamplePrep
Eric holds a B.S. in chemistry from Kean University. His current role at SPEX® SamplePrep involves managing all phases of application development including specifications, data collection, literature research, reporting and presentations. He serves as product manager and an internal ISO 9001 auditor; a technical expert, traveling domestically and internationally for customer visits and tradeshows. Prior to joining SPEX®, Eric worked as a R&D and QA chemist and currently also serves as an instructor at the International Center for Diffraction Data and the London X-ray Consulting Group.

Webinar Q&A

Are there meaningful DIY ways to measure metals in pet food?

Not that we are aware of. The heavy metal content is extremely low in these samples, and we doubt there is a DIY method for testing such elements at these concentrations. Most at-home tests are strip tests, designed for a positive or negative result and only roughly detect the present of some elements. Those individuals looking for heavy metals testing should contact a contract food testing laboratory. 

Are there any DIY test for additives, melamine and cyanuric acid?  I know it is not the topic of the presentation, but it is good to know.

There are multiple simple DIY tests for melamine in the literature. For example, run a Google search with the term “test for melamine”, and you will find various handheld devices and kits. They are mostly used for testing mill, but some should work on pet food. Most DIY tests do not give you a quantitative result (at best it is usually semi-quantitative). DIY tests will not always detect the trace level compounds which could still be damaging to health. The best way to test for melamine or elemental contamination is to send a sample to a reputable accredited laboratory for testing.

Is it possible to remove all these toxic elements, and how does that affect the cost of animal food production? 

Toxic metal remediation is not an efficient or inexpensive process for food. There are no commercial remediations for food to our knowledge. The sure way to remove elements is to destroy the form of the food and carry out specialized processes. This may be an interesting research experiment, but it won’t lead to purified, edible food.

Can these contaminants come from the metal container packaging?

None of the samples in the 2019 study were packaged in metal containers as we received them. We do not know how the food was produced or stored prior to packaging. But packaging can play a role in contamination.

How about mercury in fish / cat food made from fish?

In our original study, we found there was little overall correlation between mercury and fish brands of pet food. We did not have canned foods in this 2019 study nor a lot of fish-based brands of dry food. If you are interested in the original study, please visit our website to see the original 2009 study webinar.

What method would be most reliable for detecting methylated mercury in fish and fish-based cat food?

Elemental species are often determined by methods such as LC-ICP-MS and other hyphenated techniques. Sometimes organoelemental compounds can be detected using organic analysis such as LCMS or GCMS depending upon the form and element.

Probably reaching but what if corn were fed to chickens, etc.? I wonder if the U (uranium) could pass that way into pet food. Of course, that would affect human consumption even more.

Heavy metal bioaccumulation is a known way that some heavy metals enter the food pathways.  From what we have been able to find, the most common route of uranium bioaccumulation is through water and aquatic life. Uranium does bioaccumulate in the bones and organs of animals and can possibly ultimately end up in the protein. It is difficult to understand the source without testing each individual raw material of the pet food to see if one or two items are the source or if the source is an accumulation through multiple smaller exposures.

Is there any correlation between the amounts of uranium in pet food and human-grade food products?

At the time we studied the human foods in 2009, there was no detectable or significant amounts of Uranium in the human proteins. We did not test other human foods in comparison.

Have you done any speciation of the high arsenic using LC-ICPMS?

At this time, we have not done speciation on the pet food. In the past we have done studies using speciation but not for this study.

Will addition of chelating agents (EDTA, EGTA, etc.) help to mitigate the toxicity? 

Not certain, but a lot depends on how the metals are interacting within the food. It’s very unlikely that this method would remove all of the metals, and it would probably have to destroy the food to be done effectively.

Out of curiosity, which of the methods can you best test for anions? 

Ion chromatography is the best bet. 

Is there a way to distinguish these bad ingredients in the pet food we buy? e.g. decode ingredients lists? A safe list of sorts to reference.

Pet food labels are very similar to human food labels; the more unrecognizable ingredients, the more fillers and additives are present. Foods with by-products, generic “meat or animal” proteins or meals are not as good as “chicken, beef, salmon, etc.”  The contaminants themselves are usually not additives and don’t find their way onto labels.

Why is the cryogenic milling so important for the digestion of the sample for testing with ICP-MS and OES? 

In order to get fully effective digestions, it’s important to crush the material down to a very small particle size in order to maximize the surface area. This ensures complete transfer of the metals into solution.

Is this instrument (freezer mill) only used for animal food or anything solid?

SPEX Freezer/Mills are used for a variety of sample types including bone and animal tissue, plant research and crop science, cannabis (plant, edibles), biotechnology (RNA/DNA), plastics, RoHS, WEEE (electrical component grinding), and forensics.

Will bacterial contamination survive the grinding? 

It depends on the sample. In some cases, bacteria strains can survive at cryogenic temperatures.

We need to be able to culture any contamination after homogenization. 

We will need more information involving your sample preparation process. 

I might have missed it at the beginning, but did you stick to one type of protein in the dry foods? Or did you analyze chicken, fish etc.?

Many of our samples were donations, so we were not able to exclusively stick to one type of protein. When samples were purchased, chicken was the first choice of protein because we had canned chicken breast for human consumption to compare over other types of protein in the first study. Whenever possible, the 2019 study tried to duplicate the brand and flavor of an original sample.

Did you test any of the dog/cat foods that are "premium" foods and do not contain any corn, wheat, soy, or animal by-products?

We included quite a few premium brands in our study but just because they are considered premium, it did not mean there was no corn product in the formulation.

To reduce moisture from condensate, assume vials must come to room temp before opening?

No, the vials can be opened immediately after removing from the Freezer/Mill using the End-Plug Extractor such as the 6808 Extractor used in the webinar.

Is there a step that can be done in the manufacturing process to analyze the ingredients for heavy metals and remove them in the MFG process? 

They can certainly run similar experiments to those we presented. However, as mentioned in an answer to a previous question, there is no easy way to remove these elements without destroying the food. If the contamination is due to aging manufacturing equipment or wear metals then the manufacturer can trace back the source and repair the problem. The same is true for contaminated raw materials which should be able to be traced by the manufacturer to the source. 

What can we do, as pet owners, to set limits for healthier food?

Consumers need to become educated as to the ingredients in all pet food and when possible understand how those ingredients are sourced.

Can you recommend any brands of dry and wet pet foods were best and worst for contaminants?

We do not comment as to brands, but the rule of thumb is to understand what is on the label. The more ingredients with by-products or unrecognizable chemicals often have more processing and lesser quality ingredients and are more prone to being higher in contamination. Brands with reputations to maintain and protect have become more proactive in their materials sourcing than less known brands or cheaper foods.

Can you recommend any types of dog foods that are the safest?

The more ingredients with by-products or unrecognizable chemicals often have more processing and lesser quality ingredients and are more prone to being higher in contamination. Brands with reputations to maintain and protect have become more proactive in their materials sourcing than less known brands or cheaper foods.

Where the most expensive the lowest in contaminants?

Brands which are considered ‘higher-end’ had less metals than the lower priced foods. Brands with known reputations also fared better than unrecognizable brands or cheaper choices. As a matter of policy and principle, we do not identify.

If you get what you pay for, how much do I need to pay for a 20- or 30-pound bag of dog food?

The price of pet food is very dynamic and like any other commodity changes with perceived quality and value. If your pet food is cheaper, it is probably full of additives, fillers and by-products while more expensive pet food has more true meat sources and less fillers. While we are not able to tell you how much to pay for a bag of food, it is not unreasonable to expect that a 20-lb bag of dog food for $2 is going to have lesser ingredients and less care in manufacturing and more potential for contamination than a similar size bag costing $20.

It would be nice to see a breakdown of the levels in the actual foods tested. I'm sure there was a great variability between them?

There was a large variation of elements in the foods which was to be expected. There were however some trends like higher arsenic or lead overall. 

What are your views on "raw" foods for both cats & dogs?  Supplement?

We have not done any studies on raw food or supplements. If the raw food conforms to the guidelines of veterinary associations then it should be an acceptable product for pets. We cannot comment on the metals in these foods or supplements since we did not conduct studies on those products.

Has any correlation been done between these data and dog health?

Officially, we were able to find one study cited pertaining to beryllium and the stomach health of dogs conducted we believe in the 1930s. Most studies for animal health or human health are performed on laboratory rodents or cattle, etc. 

Would human-grade pet food be different?

We are not aware of a designation of human-grade pet food. We do not believe that this is a recognized classification for pet food and are not sure if we can answer the question. Human foods, however, are just as prone to contamination as pet food.

Are you familiar with the similar work by the independent lab in Colorado?

We are not familiar with any other studies that have been conducted recently. There have been papers that were presented in the past after our first study that confirmed the presence of metals in pet food. We would be very interested in any studies that anyone can share with us on this or any other metals in food topic.

Excellent work, much appreciated. Interested in establishment of safe limits and long-term consequences of market, such as poorer countries receiving compromised materials.

Thank you for your interest. It is always interesting to see that these limits are not only questionable or absent for human food as well, in both the US and around the world. Some very toxic elements have a lack of dietary guidance for humans let alone pets. 

What support programs does Cole-Parmer have for institutions of higher learning in the area of mineral elemental analysis? Also, for nano particles of pcb and plastics.

SPEX companies have many tools and standards for use in elemental testing and mineral analysis.  We are happy to provide you with any information or literature you need to help in your work. Cole-Parmer is also committed to helping their customers with their laboratory needs. We will be happy to forward your information to your SPEX and Cole-Parmer representatives for further help in your analyses.

Are there currently any bills in congress to address further food safety for animals?

We are not aware of any current legislation at this time, but the FDA and pet food advocacy groups would be the best source on the state of the laws.

Are you aware of whether the pet food manufacturers "prescreen" their raw ingredients via XRF or some other method prior to using them in their formulations? And does FDA do any routine monitoring of these products? 

Each manufacturer has its own procedures for screening and verifying raw materials. The current law requires a certain amount of due diligence from suppliers and manufacturers to avoid gross contamination and intentional adulteration. As for XRF, we are not aware if it is used for routine screening, but it is certainly possible. However, XRF screening may not able to detect low enough levels of elemental contamination, just larger scale contamination. The FDA can screen and inspect facilities under the new laws, but we are not privy to their inspection policies.

IAMS, when owned by P&G, had standards their suppliers had to meet.

In the past, we have discussed pet food with different suppliers at conferences and many of these companies have some policies in place to screen their raw materials but not all of them screen for trace contaminants or heavy metals. In some cases, the contamination could be a result of cumulative exposures from many sources from raw materials to manufacturing processes.

I've been in the IAMS manufacturing plant during cat food production, and the fish was disgusting, but they were using a lot of real fish.

It is good to know that real ingredients were being used in pet food.

When are you going to do a similar study on cannabis/CBD products...? it’s most definitely needed, particularly additional elements to Pb, Cd, As and Hg. 

In the past we have done a study on hemp and CBD oils and found heavy metals in those products. 
Please see the SPEX CertiPrep website for this study and the others we have conducted.