About 15 years ago I was awakened in the middle of the night by itching on my palms and the bottoms of my feet. I felt flushed like a niacin overdose but this was a magnitude of that sensation I hadn't experienced before. When I stumbled to the bathroom to investigate. I didn't recognize myself in the mirror. My face was so swollen that my lower lip was splitting down the middle. I figured I was having an allergic reaction of some sort. After hundreds of milligrams of Benadryl and a few hours in a warm bath, I began to deflate.

Growing up, I had experienced a few minor allergic reactions but nothing to this extent. Being a scientist in the making, I launched my own investigation. I immediately targeted my previous night's dinner, which was sushi, my favorite food.

To make a long story short, over the course of several weekends, I performed many experiments where I went back to my favorite sushi bar, ordered the same meal I had that night, only eliminating one item each time until the symptoms returned. The culprit was Amaebi, or spot prawns. They are a delicious cold water Northern shrimp known--and named--for their sweet taste and edibility in the raw form. Oddly enough, it wasn't their raw bodies but the deep fried head that caused this allergic reaction. I had it narrowed down to a reproducible, validated, and verified experiment where I would stop by, order just the fried head, wait eight to nine hours, and bam!--swollen face, itchy palms and feet, and split lip. 

Each time, this happened. Also, this allergy is limited to only that specific part of that specific shrimp.

Fortunately, no one has decided to sneak fried shrimp heads into a dietary supplement yet, so I have very little to worry about. Unfortunately, there are numerous other known allergens, as well as dietary restrictions, that are far more serious than my trials and tribulations with shrimp heads. It's not hard to find a label warning for any of them either. The most common ones today are tree nuts, gluten, soy, egg, and dairy.

Allergen testing is a serious issue, because a hidden allergen can quickly cause the death of a customer, followed shortly by the death of the brand or product. If you are lucky, only a recall will be required.

Enter the testing lab. Whether it be internal or external, these tests are not suggestions but requirements—and people aren't as curious (and forgiving) as I was. There are handful of good external testing labs that are tooled up and can perform these tests on your ingredients and finished products. The tests are generally published AOAC methods looking for traces of one protein or another. 

"It's expensive," you say. Well, that’s the cost of doing business in today's marketplace. A company's reputation is based on a clean product, and that doesn't involve guesswork or expecting people's immune systems to make up for a manufacturer’s carelessness. You have to take these requirements seriously, the health of your business, and your customers, depends upon it.