Marty, my next-door neighbor, has been eating my microgreens for months now, and he calls me up last week and asks out of the blue, “Hey Andrew, can microgreens make you sick?”
Turns out, he had read an article that mold on microgreens was common. He just wanted to know are microgreens food-safe and do growers have to follow government standards.
As a microgreens grower and nutritionist, I created this post to show you the efforts that go into microgreens food safety and the information about plants that you shouldn’t grow or eat as microgreens.
Microgreens are food safe. Most governments have preventative controls and food safety rules for growers that protect consumers from becoming sick with bacteria like Salmonella. But you can take precautions like washing your microgreens before eating and avoid growing certain plants as microgreens.
Maybe you’re new to microgreens and thinking of growing and selling them or just growing them in your kitchen or on your windowsill. Maybe you want to try them on your salad for the first time and concerned are microgreens food safe.
If you live in Australia, New Zealand, Canada, the US, or any nation for that matter, be assured that there are standards, regulations, and guidelines microgreens are safe.
So, there are one or two things you might want to know about microgreens food safety, whether you are thinking about growing, selling, or buying them.
Because, while the US FDA does “encourage microgreen operations to consider voluntarily implementing the standards” of the Food Safety Modernization Act of 2011 (FSMA), they are voluntary.
US Food and Drug Administration | Safe Handling of Raw Produce
Microgreens are Safe: Preventative Controls and Food Safety Rules
Fruits, vegetables, meats, and just about all fresh produce can pick up harmful bacteria from many sources, from contaminated soil and water, to your contaminated cutting board.
Every now and again we hear news some of an outbreak of a food-borne illness, especially Salmonella, or someone you know got sick from at a restaurant.
But other such pathogens – Pythium, Phytophthora, and Listeria – exist.
But every country in the world has efforts to keep food safe and protect you from getting sick.
For example, if you’re reading this post in Australia or New Zealand there is the Food Standards Australia New Zealand Act 1991(FSANZ). If you’re in Canada it’s the Canadian organic regulations for Microgreens Terms and definitions (CAN/CGSB).
In the US, we have the Food Safety Modernization Act of 2011 (FSMA).
Microgreens are TCS Safe
Foods that grow bacteria more easily and quickly than other foods are a higher risk and are referred to by the FDA Food Code as “Time/Temperature Control for Safety food” or “TCS food” – (formerly called “potentially hazardous food” (PHF)).
Microgreens and cut leafy greens and sprouts are similar and although cut leafy greens and sprouts are TCS/PHF, the FDA currently states that microgreens are not TCS/PHFs.
Microgreens need less warm and humid conditions than sprouts do. You eat only the leaf and stem, not the root and seed.
The potential for bacteria growth is much smaller in microgreens.
Microgreens are TCS safe. However, commercial microgreens growers must follow rigorous FDA Guidelines.
The rule does not cover farms that have an average annual value of produce sold during the previous 3-year period of $25,000 or less.
The rule provides a qualified exemption and modified requirements for farms that meet two requirements: (1) The farm must have food sales averaging less than $500,000 per year during the previous 3 years; and (1) the farm’s sales to qualified end-users must exceed sales to others. A qualified end user is either: (1) The consumer of the food or (2) a restaurant or retail food establishment that is located in the same State or the same Indian reservation as the farm or not more than 275 miles away.
Learn how the US Food and Drug Administration is using the Food Safety Modernization Act (FSMA, 2011) to protect you.
Microgreens are Safe to Eat
Salmonella and Escherichia coli O157: H7 have been the major causes of sprout-associated illness outbreaks.
Most restaurants in the US no longer serve sprouts on their menus. Walmart Stores discontinued selling sprouts in 2010. In 2012 Kroger announced that it would no longer sell sprouts in its US supermarket chains.
The CDC maintains the National Foodborne Disease Outbreak Surveillance System, and the Foodborne Diseases Active Surveillance Network (FoodNet).
|Product Category (examples of possible foods for evaluation)||Pathogens of concern||Types of process control1 (alone and in combination)|
|Fruits and vegetables||Salmonella spp., Shigella spp., enterohemorrhagic E. coli, L. monocytogenes, Bacillus cereus, Y. enterocolitica||Production control (Good Agriculture)|
Table 1 Standards for the Growing, Harvesting, Packing, and Holding of Produce for Human Consumption
Raw microgreens are safe to eat, just like any other vegetable, if they’re grown, handled, and processed properly. Microgreens need to be grown in a deliberate and careful way to avoid food borne illness through pathogen growth.
I could find no record of a food-borne outbreak associated with eating microgreens.
However, I did find microgreens recalls. A good source is the Food Safety News site. Just search “microgreens.”
By Themselves, Microgreens don’t make you sick
Many foods contain toxins or get them through handling or processing. However, adverse reactions to food are low because of governments’ no-nonsense actions worldwide.
The signs of getting sick from eating contaminated food include
- abdominal pain, and
- flu-like symptoms, such as fever, headache, and body ache.
When growing microgreens at home, pay special attention to the quality of the seeds and soil you use. Your most problematic issues will be mold, mildew, and fungi.
You can consider microgreens safe to eat. But you can avoid getting sick eating them by following the simple rules associated with eating or handling “raw food.”
The Things That Could Make You Sick
The following are the contaminates most associated with microgreens.
Listeriosis is a food-borne infection caused by Listeria bacteria.
Common Listeria symptoms are muscle aches, fever, flu symptoms, nausea, and diarrhea.
It can be very serious for pregnant women, newborns, the elderly, and anyone with a weakened immune system.
Salmonella infection (salmonellosis) is a common bacterial disease that affects the intestinal tract.
Infection occurs through contaminated water or food.
You develop diarrhea, fever and abdominal cramps within eight to 72 hours.
Most healthy people recover within a few days without specific treatment.
Molds are microscopic fungi with branches and root that look like tiny threads.
They grow in damp and moldy environments.
Exposure to molds can lead to a stuffy nose, wheezing, and red or itchy eyes, or skin.
A few molds, in the right conditions, produce “mycotoxins,” poisonous substances that can make you sick.
How to Identify When You Are Sick, and the Remedy
If you believe eating microgreens made you sick, then know the symptoms so you can identify the problem to a health professional.
Know the Symptoms
If you eat microgreens that contain bad bacteria, you will get sick within 1 to 3 days.
Some people have an immediate reaction. Others see no symptoms for 6 weeks.
Unless it is a serious illness, you are unlikely to develop any chronic or life-threatening health problems.
You will recover within a short time.
The symptoms of a food-borne illness can include:
- Vomiting, diarrhea, and abdominal pain
- Flu symptoms, such as fever, headache, and body ache
If you think you or a family member has a foodborne illness, contact your healthcare provider.
Contact the nearest Poison Control Center. They give poison and treatment advice by phone. You can reach any poison center by calling the same telephone number, 1-800-222-1222.
For more information on preventing food-borne illness, see Safe Food Handling: Four Simple Steps, https://www.fda.gov/media/107837/download
Other Worldwide Poison Centers
- Poison Centers and Clinical Toxicologists across the World: https://www.eapcct.org/index.php?page=links
Taking Care When Growing at Home
If you’re growing or planning to grow microgreens at home, there are a few food-safety items you need to cover.
Radish, watercress, Swiss chard, and Thai basil microgreens are very susceptible to disease.
So, it is very important you buy seeds from a reputable company and choose soil free of harmful bacteria.
Avoiding Root Rot
Your most serious threat to microgreens is Pythium and Phytophthora.
Pythium is a fungus that causes root rot in young seedlings. This is a persistent problem in areas over-irrigated or not drained right.
Phytophthora are a special fungus called oomycetes.
They are water molds and destroy the root systems of microgreens.
Preventing Seedling Damping Off
The cotyledons (first leaves), roots and stems of microgreens seedlings can get an infection called “dampening off.”
It is a fungus or mold that grows in cool and wet conditions.
Your seedlings are infected if they cannot germinate, or the first leaves are limp or look brown, or you see fluffy white cobweb growth.
Fuzzy white mold is a common issue for microgreens, but the fungus does not hurt your growing plants.
Helpful hint: Don’t mistake the tiny roots of microgreens for mold. Basil seeds develop a jelly-like coating that looks moldy. This is normal.
I have lost whole trays of microgreen seedlings to root rot. Make sure you keep your soil damp, but not too wet.
You should use sterilized containers with good drainage and clean, new potting soil.
I haven’t tried this, but some growers suggest you use a heating pad under the growing container to warm soil to 70-75°F.
There is no cure for plants that have damping off. You can prevent the problem by providing good air circulation.
If you can’t find microgreens seeds to grow, look for “food grade” or “organic” labels and read the fine print.
Seeds are very susceptible to disease.
Inspect your growing seeds for mildew.
You should try sterilizing your seeds with food grade hydrogen peroxide.
Cinnamon Fungicide Control
Home gardeners swear by cinnamon.
Cinnamon will help prevent mildew by killing the fungus.
Make a cinnamon spray. Stir some cinnamon into warm water and allow it to steep overnight. Place in your misting bottle.
The Microgreens to Avoid
After growing about 10 different varieties of microgreens, some don’t taste nice, like Swiss chard. They don’t make me sick.
But I know of some plants that I wouldn’t, and you shouldn’t, grow or eat.
Tomatoes, eggplants and potatoes are from the nightshade family.
Don’t grow them as microgreens.
You should discard the green part of the potatoes. It is bitter and contains solanine, which eaten in great quantities can make you sick. Symptoms of solanine poisoning include:
- Fever or hypothermia
- Slow pulse and/or breathing
- Stomach or abdominal pain
We use oxalic acid in bleach and antirust products!
It inhibits calcium absorption which can lead to kidney stones.
Eat too much and you might vomit and get weak.
Dark leafy green vegetables such as kale, spinach, and rhubarb contain plentiful amounts of oxalic acid (or oxalate). But don’t worry.
The research I found says if you’re 145 pounds (65.7 kg), you’d need to eat about 11 pounds (5 kg) of rhubarb leaves, or 7 pounds (3.2 kg) of spinach at one sitting before somebody would need to call the ambulance.
Buckwheat contains fagopyrin, a substance that when ingested in significant quantities causes your skin to become hypersensitive to sunlight.
Exposed areas of your skin would turn pink or red within minutes, and the area burns. Some people also get a numb, fuzzy, and buzzing feeling.
Unlike the shoots of the plant, however, buckwheat microgreens contain only trace quantities of fagopyrin and don’t pose a problem.
However, I avoid them.
You can consider microgreens safe to eat.
But, as with any “raw food”, pregnant women, the elderly, young children, and people with weakened immune systems are at risk of serious illnesses, life-threatening infections and other complications.
But you can avoid getting sick eating microgreens by following the simple rules associated with eating or handling “raw food.”
When buying them online, at the farmers market, or at upscale food stores, look for the certified organic label.
If you’re growing them yourself, start with sterile containers, certified organic seed and seedling mix, good air circulation, and not too much water or humidity.
- Wash your hands.
- Always cut your microgreens above the stem/root line.
- Wash the microgreens before eating, even if the package says they have been “triple-washed.”
- Store your microgreens in the fridge in a ventilated container.
Can microgreens make you sick? What do you think? Comment below.
Where can I find information about my country’s microgreens safety regulations?
Wherever you are in the world and reading this, you can find information about yor country’s food safety regulations here: https://www.emergobyul.com/blog.
How long can I store microgreens safely?
Most microgreens are consumed locally or regionally because of the short shelf life and the need for refrigeration in transport. My post, “How Long Can You Store Microgreens At Home” goes into more details.
I’ve learned a lot about microgreens, how good they are for you, and what you can do with them. Check out my guide, “The Beginner’s Nutritional Guide to Incredible Microgreens.”
I’m the co-founder of JPureFarms, a startup. I live in Atlanta, Georgia, and enjoy urban farming, growing and writing about microgreens and their incredible health potential. I love my greens!