An Opportunity to Get Lead Smart

A screenshot is going around: an app called Oasis is saying Premier Protein is "3,116% lead." That sounds terrifying. It's also not quite what's being measured. Here is what the underlying number actually is, why the percent framing breaks down, and a calculator that does this the right way for any food you care about.

What the 15.58 Number Really Is

The screenshot shows one scoop of Premier Protein 100% Whey Chocolate Milk testing at 15.58 micrograms of lead. That part is real. The "3,116%" headline is just 15.58 divided by 0.5 mcg, which Oasis labels "daily limit."

0.5 mcg/day is the California Prop 65 MADL for lead. It's calibrated to reproductive harm and is the most conservative threshold any U.S. agency publishes. The FDA Interim Reference Level for dietary lead (revised 2022) is 8.8 mcg/day for women of childbearing age and 2.2 mcg/day for kids six and under. Both are also conservative. None of them are a "safe" number. Lead has no safe biological threshold.

Same 15.58 mcg. Different denominators. Totally different headlines:

All three are "true." None of them tell you what to do next, because the reader almost never sees which denominator the writer picked. The denominator is doing all the work, and it's invisible in the headline.

The Same Lead, Sliced Multiple Ways

To make this concrete: that one scoop of Premier Protein, sliced different ways using typical label values for a whey isolate scoop:

Every slice describes the same lead. Most of them are useful. The "% of an unspecified ceiling" is the one that's not.

Why "% of Daily Limit" Is the Wrong Headline

Lead exposure is additive. Every food, every dose, all day, sums up in your body. Half-life in blood is ~30 days. Half-life in bone is ~25 years.

A percent of one product against one threshold is meaningless on its own, because no one eats one product. Two scoops of Premier in a morning shake is 31.16 mcg, which is 354% of the adult FDA daily ceiling before lunch. That leaves nothing for cinnamon, chocolate, leafy greens, baby food, water, or anything else that contains traces of lead, which is most of the modern food supply.

And then you have to ask: a percent of what? Of California's reproductive MADL? Of the FDA adult IRL? Of the FDA child IRL? Of a CDC blood-lead reference? Of zero, because there is no safe level? You can pick a denominator that makes any number look harmless or catastrophic. Whichever you pick, the reader does not see it.

PPB Has the Same Problem

A lot of third-party lead reports get quoted in parts per billion (ng of lead per gram of food). PPB tells you contamination density. It does not tell you exposure, unless you also know the dose.

90 ppb in a 30g protein scoop is 2.7 mcg per serving. 90 ppb in a 200g chocolate bar is 18 mcg per serving. Same ppb, very different exposure.

This is why "X is below 5 ppb so it's safe" or "Y is above 100 ppb so it's poison" misleads people. You cannot grade exposure without dose. You cannot grade daily intake without summing every dose. Threshold-by-ppb is the same kind of mistake as headline-by-percent: a number that looks like it answers the question, but doesn't.

The Framework That Actually Works

Step 1. How much lead is in one serving you actually eat (in micrograms)?

Step 2. How many servings per day?

Step 3. How much from everything else you ate?

Step 4. Compare the daily total to the FDA IRL. Adult: 8.8 mcg. Child six and under: 2.2 mcg.

Step 5. Don't aim for a percent. Aim for as low as you can get it. There is no biologically safe amount of lead. The IRL is a regulatory ceiling, not a safety threshold.

The Calculator

Two ways in. Tab one if your number is in ppb (most lab reports, most third-party testing). Tab two if your number is already in micrograms per serving (the Oasis screenshot, FDA TDS data, anything that already did the dose math for you). Move the sliders.

The calculator above handles one food at a time. Lead is cumulative across your whole day, so add what you get from this food to what you get from everything else.

Jump to another calculator

Universal Food Calculator ~1,300 whole foods. Type what you ate, get µg of lead per day. Baby Food Toolkit The baby-food circuit. Six tools, one tab each, AB 899 + HBBF datasets.

An Open Letter to Oasis

Want to Check a Food That Isn't on My List?

The calculator above handles any product you have a ppb or mcg number for. The Universal Food Calculator covers ~1,300 foods that have been tested or pulled from peer-reviewed sources. The Baby Food Toolkit covers AB 899, HBBF, and a few other baby-food datasets. Between them, you can build a real daily-intake picture instead of a single attention-grabbing percent.

Open another calculator

Universal Food Calculator ~1,300 whole foods. Type what you ate, get µg of lead per day. Baby Food Toolkit The baby-food circuit. Six tools, one tab each, AB 899 + HBBF datasets.

Numbers used on this page. FDA Interim Reference Level (dietary lead, 2022): 8.8 mcg/day for women of childbearing age, 2.2 mcg/day for children six and under. California Prop 65 MADL for lead (reproductive harm, OEHHA): 0.5 mcg/day. The 15.58 mcg-per-scoop figure is reproduced from the Oasis app screenshot for Premier Protein 100% Whey Protein Powder, Chocolate Milk; I have not independently verified the lab data behind it. Typical serving label values used for the per-protein and per-calorie slices: ~30g protein, ~160 kcal per scoop.