As a food, dietary supplement, or personal care product manufacturer, your products are expected by the public and by regulatory bodies to be safe for use and consumption. But what is safe, exactly? Product safety can involve everything from how the product is labeled (if it contains gluten, does your label state that?) to whether pathogenic microorganisms are present in your product. There are entire publications dedicated to ensuring a high-quality finished product, so we are going to focus here on how to determine whether your product meets microbiological guidelines for human use and consumption.

This is one area where we at Daane Labs field a ton of questions because the guidance available from regulatory bodies like the FDA is pretty vague. Our clients want a list of organisms to test for and the acceptable levels. We hate to be the bearer of bad news, but no such lists exist. It’s up to you to develop that list and those levels, called product specifications, for your product yourself. But don’t worry! This blog post isn’t over yet and we’re here to help you develop those specifications for your products.

Big picture: your individual product specifications should be a reflection of the nature of your product. This includes everything from raw ingredient quality, manufacturing process, packaging, storage conditions, intended use, etc. You should have a solid understanding of what the lifecycle of your product is to be able to make the most comprehensive, competent decisions about what to test for and how. Let’s start with a a couple examples of what product specifications may look like and we’ll work our way backwards on how we got here:

Example 1 – Turmeric Capsules
Organism	Specification
Total Aerobic Count	<10,000 CFU/ gram
Total Yeast & Mold	<1,000 CFU/ gram
E. coli	Negative in 10 grams
Salmonella spp.	Negative in 10 grams

In the above Example 1, this product would be “allowed” to have up to 10,000 CFU/g total aerobic organisms, up to 1,000 CFU/mL yeast and mold, and no E. coli or Salmonella spp. at all. 

Example 2 – Eye Drops
Organism	Specification
Total Aerobic Count	<10 CFU/ mL
Total Yeast & Mold	<10 CFU/ mL
Total Coliform	<10 CFU/ mL
E. coli	Negative in 10 mL
Salmonella spp.	Negative in 10 mL
Pseudomonas aeruginosa	Negative in 10 mL
Burkholderia cepacia	Negative in 10 mL

In Example 2, the levels are much more stringent for the quantifiable organisms and there are additional pathogens, Pseudomonas aeruginosa and Burkholderia cepacia, that must be confirmed absent in the product.

So — why the difference? You would think that if Pseudomonas aeruginosa is a no-go in one product it should be a no-go in all products, right? You’d be right, but with a caveat. The nature of your product will determine the likelihood certain organisms will be found there, thereby often rendering testing for certain organisms wasteful. For example, Pseudomonas aeruginosa and Burkholderia cepacia are both Gram-negative rods heavily associated with industrial water systems. If your entire manufacturing process is void of such a system, such as dry-blending and filling turmeric capsules, you would waste a lot of money testing for waterborne organisms. Manufacturing eye drops, on the other hand, would require industrial deionized water systems and would therefore risk introducing waterborne organisms into the product.

Now that we’ve covered how to determine which organisms to test for, we’ll get into how to set those levels for things like Total Plate Count. This will ultimately be decided, again, by the nature of your product. Herbal dietary supplements are an excellent example of this principle. The American Herbal Products Association (AHPA) has specification recommendations for “powdered botanic extracts” as high as 10,000,000 CFU/ gram for total aerobic plate count. Such a high level of microbial activity is considered acceptable because the product contains “dirty” raw plant material. Setting the quantitative specifications depends on the microbiological activity of the ingredients going into the product, whether the product undergoes any sort of pasteurization or sterilization, at what temperature the product is stored and used, etc. You may even find it useful to run several repeat tests on your ingredients and finished product to get baseline values for microbes in the product, and set specifications accordingly. 

Whether the presence of bacteria or fungus is an inherent property of the product, such as turmeric capsules, or an acceptable risk that can be mitigated, it is important to understand all of the challenges your product faces. There are a variety of quantitative and qualitative methods that have been published by the USP, FDA/ BAM, AOAC, and more, and we perform many of these methods here at Daane Labs. If you are struggling with method selection, the team at Daane Labs are experts in current methodologies and we are always happy to help our readers make the best scientific decisions you can for your business.

Since Daane Labs is a testing laboratory rather than a testing consultant, we are unable to direct you on what your product specifications should be. What we really want you to know is that as long as your specifications are guided by a comprehensive understanding of your product and you have documented reasons for testing plan, you’re on the right track. Regulatory bodies want to see that you know the risks to your product and that you are doing your due diligence to prevent those risks from reaching the public. 

Disclaimer: Daane Labs does not set product specifications and the content of this blog post is not intended to set specifications for any existing or future products.

References

http://www.ahpa.org/Portals/0/PDFs/Policies/14_0206_AHPA_micro_limits_comparisons.pdf

Daane Labs designed our mold reports to be understandable by everyone from highly-specialized industrial hygienists who take mold samples to homeowners with allergies and questions. Our hope here is that regardless of where in that spectrum you fall, this blog will help you understand that report a little bit better. If you’re looking at a Daane Labs mold report and have some questions about the Background, this one is for you. But before we get into that, you’ll need to know a bit more about how exactly your mold samples are collected and analyzed.

Samples are collected by using a pump to pass a known amount of air over an adhesive surface inside a disposable device called a “cassette”. As the air is pumped through the cassette and over the adhesive surface, the particulates in the air get stuck to the adhesive. These samples are given to the lab for processing, where we open the cassette and use a microscope to look at that adhesive surface where all of the particulates have gotten stuck. We count and identify the mold spores on the adhesive, but there’s usually a lot more than just mold in each sample.

All that other “stuff” in the sample is better known as the Background, and we assign a value to give you an idea of how much “stuff” is in the sample. Short of some extraordinary event that severely impacts outdoor air quality, such a wildfire or nearby building demolition, the Background of outdoor samples is typically pretty low and does little to impact the analysis. The Background of indoor samples, however, can vary greatly from room to room within the same house and frankly, it’s what we get the most questions about. So let’s get into it.

The Background of indoor samples is usually composed of the typical components of house dust: human skin, pet dander, insect fragments, fibers from clothing, etc. The value of the Background directly correlates to the amount of “stuff” in the sample: 1 indicates there are almost no particulates in the sample and 5 indicates that the sample has essentially been overrun by particulates. So what does that mean? We’ll use an analogy we’ve leaned on for years to explain why the Background matters and how it impacts your test results.

Imagine you are looking at an old oak tree, full of large branches and lush leaves. You are asked to count the number of birds in the tree. You could probably count the birds on the lower branches, maybe some of the birds sitting right on the outside of the tree. But you could assume there are birds in the tree that are hidden by the branches and leaves that you are unable to count. So even if there are 100 birds in that tree, maybe you can only see 8 or 12 of them. Compare that to counting the birds in a dead tree with no leaves and only a handful of branches. You could probably see just about every bird in that tree and you would be more confident in that bird count, right?

Similarly, we can see just about every single spore in a sample with a low Background and we can make the assumption that we cannot see every single spore in a sample with a high Background. This is called a negative bias and it increases as the Background value increases. This doesn’t mean that a report with a high Background is wrong or that the lab report is any less useful… not at all. The Background simply aids the investigator in determining how to interpret the report and next steps. The investigator may have the expertise and project-specific knowledge to apply the data to that project, or they may decide to collect additional samples. While Daane Labs staff is always more than happy to provide insight into the data within the report, interpreting how a high Background impacts next steps is left to the investigator who collected the samples, such as a building inspector or mold assessor.

Air sampling for fungal spores has been in the limelight for a long time. The yin to air sampling’s yang is surface sampling and we think it deserves some attention as well. Something that often gets overlooked with air sampling is that the mold isn’t actually growing in the air – that’s just where evidence of fungal growth is most easily found. Fungal growth occurs on surfaces and releases spores into the air, and then those spores land in the air sample and “Ah ha!”, mold has been found. But what about that surface? Where exactly is that mold growing? That is where surface sampling comes in. Surface sampling may not be required for every project, but it can add value to any project when done correctly and purposefully. Here, we explore some of the most common techniques and materials used by industry professionals for surface sampling for mold.

 

Bio-Tape™  Slides

Bio-Tape™  slides are sterile, flexible, plastic microscope slides that consist of an adhesive sampling area and label, and are the ideal tool for sampling flat surfaces such as walls, tables, joists, etc. The adhesive area should be lightly and evenly pressed to the surface in question to collect surface particulate. These are some of Daane Labs’ favorite surface sampling products because we can stick them straight under a microscope for analysis with very minimal prep time (read: faster analysis… read: faster results). Oh, and what’s that? Daane Labs provides these for free? Yes, yes we do. 

 

Copan Swabs 

Copan swabs are another product that Daane Labs provides to clients free of charge. These swabs are sterile (like the Bio-Tape™ slides) and are best used for sampling surfaces you can’t quite get to with a Bio-Tape™ slide. These could be areas like the corner of a windowsill, inside the slats of an A/C vent, between bathroom tiles, etc. Roll the swab evenly across the surface you are sampling, ensuring all sides of the swab come in contact with the surface. 

 

Office Tapes

While we recommend using a product specifically designed for surface sampling, we understand that won’t always be the best option for our clients. Maybe you ran out of supplies (Let us know and we’ll get them to you for free!) or maybe you have a personal preference after years in the field. Regardless of which type of office tape is used, the sampling technique should be about the same. We recommend holding the tape with your thumb and pointer finger, sticky side out. Lightly touch the tape to the surface you are sampling, then stick the tape to the inside of a plastic sandwich bag or directly to a microscope slide. Here are the types of office tape we’ve seen used over the years and what we have to say about them:

 

• Transparent Scotch® Tape
  • This type of tape is a good replacement option for Bio-Tape™ slides because it is transparent, narrow (fits on a microscope slide), and affordable. 

• Frosted Scotch® Tape
  • Frosted tape appears frosted to the naked eye because of microscopic bubbles and imperfections in the tape. These bubbles and imperfections make it very difficult to get a clear picture of what is actually on the sample, and is not an alternative we would suggest using. We can and have and will analyze frosted tape samples, but we still think it is important for you to understand its shortcomings as a surface sampling product.

• Packing Tape
  • Packing tape has similar benefits to Transparent Scotch® Tape, except that it is much wider and therefore requires additional processing by the lab. We are unable to analyze an entire piece of packing tape and must either cut or sub-sample the tape to get it under the microscope. 

 

Q-Tips

Q-tips are non-sterile cotton swabs that can be used in a pinch to collect a surface sample, but it is not something Daane Labs recommends doing regularly. Any non-sterile product used for sampling risks having something already on it, so there can be no telling if what is on the swab was there before or after sampling. Additionally, Q-tips tend to be softer and more delicate than Copan swabs and can deteriorate during processing (i.e., cotton tip can somewhat come apart when exposed to lactophenol cotton blue staining agent).

 

Bulk Samples

A bulk sample is essentially when the material suspected of growing mold is itself submitted rather than taking a surface sample. Examples of bulk samples we have received are cutouts of drywall, HVAC insulation, wallpaper, roof shingles, baseboards, etc. It is difficult to provide a lot of guidance on this sample type simply due to the fact that these samples can vary so widely. Ideally, bulk samples should be small and representative of the area of concern. 

Choosing the right microbial testing laboratory to meet your business needs can be a daunting task. There are myriad factors to consider while you decide which lab you should use: laboratory reputation, location of the lab relative to you, pricing, available testing… the list goes on. Every business has unique needs and may choose to prioritize these many factors slightly differently. There are, however, a handful of core qualities that are the cornerstones upon which every great lab is built.

1 – Accreditation

It is impossible to overstate the benefits of using an accredited laboratory. Accredited labs voluntarily pay for and undergo regular audits by third-party companies called accreditation bodies. These audits involve industry experts visiting the lab and doing a deep dive into the lab’s processes to ensure that specific technical, safety, and quality standards are being met by the laboratory. The “gold standard” of standards for labs to meet is ISO 17025.

ISO is the International Organization for Standardization and they develop the standards by which items are manufactured and tested. You may remember that there were many “eclipse glasses” being sold leading up to the 2017 Total Solar Eclipse, and the media recommended consumers purchase only those glasses labeled to be ISO 12312-2-compliant. The idea there was to ensure consumers were purchasing products that met specific quality standards to ensure safe eye protection. The idea for labs is exactly the same. Using a laboratory with an ISO 17025 accreditation should give you peace of mind that high quality standards are being met while your samples are tested.

2 – Agility

Routine testing of any kind is typically, well, pretty routine. 9 times out of 10 you’re requesting the same types of tests and getting the results you expect in the time-frame you expect. What happens, though, when something unexpected does happen? What about that obscure special project you have? What if you have an unexpected sampling event and need testing started on a weekend?

Those are the times when the rubber meets the road. Utilizing a laboratory capable of quickly adapting to meet your needs can be the difference between a hiccup and a catastrophe. Admittedly, agility can be a difficult quality for you to assess before committing to using a particular lab.

Here’s the test: how easy is it for you to talk to the decision maker? The easier it is for you to speak directly to the director or owner of the laboratory, the easier it is going to be for the lab to adapt to meet your needs. If you have to call a sales rep, get transferred, put on hold, get transferred to a middle-manager, and eventually hear “someone will get back to you”… that should be a red flag. Truly agile and adaptable labs have easily accessible and involved upper-management who prioritize the unique and unforeseen challenges that businesses like yours face every day.

3 – Scientific Literacy

Microbial testing laboratories are scientific businesses, and they are always directed and managed by scientists… right? Wrong. While it is true that many labs get their start with scientists at the helm, many of those labs are eventually owned and operated by non-scientists.

Microbial and analytical testing laboratories with scientifically-literate leadership will be more prepared to help you with the technical aspects of your projects. These industry experts have years of education and technical experience to draw upon when faced with a new challenge. When there is no disconnect between the scientific foundation of a laboratory and the daily functions within the lab, the overall quality of the work flourishes.

References

• American Astronomical Society: National Science Foundation. “How to Tell If Your Eclipse Glasses or Handheld Solar Viewers Are Safe.” Solar Eclipse Across America, 2017, https://eclipse.aas.org/eye-safety/iso-certification. Accessed 6 February 2021.

Hello there, and welcome to our very first blog post! We are thrilled to be getting this blog up and running and want to make this a valuable resource for our readers. Having been in business for over 10 years, the team at Daane Labs are experts in what we do and want to make you an expert as well. To that end, we are distilling our decades of combined education and experience into a blog packed with science, regulatory interpretations, and technical advice (and maybe a dad joke or two?).

We will be posting monthly on topics ranging anywhere from how exactly a spore trap is analyzed to interpretations of the Food Safety Modernization Act. We will provide content for food safety professionals, environmental consultants, sterile product manufacturers, homeowners, and everyone in between. We really do want to be a blog for everyone.

Furthermore, our goal is to strengthen the relationships we have and foster new ones. We see this blog as another way to build trust among our current and future clients, as well as an opportunity to engage with other industry experts. The more we all know, the better — right?

Right! So, join us as we start out on this blogging journey and stay tuned for our upcoming posts.