The Dirty Truth About Industrial Grade Lye
Part 4
Yes, It Saves Money.
Let's Do the Math.
Look, we're not going to pretend the cost difference doesn't exist.
That would be dishonest, and Seedsquatch has a strict no-dishonesty policy (we have a reputation to maintain, and the Sasquatch community takes integrity seriously).
Food-grade lye runs roughly $7–$9 per pound. Technical-grade drain-cleaner lye at hardware stores runs about $3.50 per pound. If you're a hobby soap maker using around 10 pounds of lye per year, you're looking at saving roughly $45 annually by going the industrial route. For a small cottage operation doing modest volume, that number might scale up to $100–$150 in annual savings.
That is real money. We get it. Ingredient costs are real, margins are thin, and nobody's out here trying to be reckless — they're trying to make a living or a meaningful gift.
But here's where the math gets uncomfortable.
The Invisible Ingredient:
Your Skin Absorbs Everything
Before we get into the numbers,
let's establish one foundational fact: your skin is not a barrier, it is a membrane. According to research cited in the American Journal of Public Health, skin can absorb between 64% and 100% of total contaminant dosage depending on the chemical structure, application site, and condition of the skin. Seedsquatch's own website notes the well-established figure of up to 60% absorption for substances applied to skin — and that's on healthy, undamaged skin. Your face and scalp absorb up to four times more than your forearm.
The absorption process isn't passive. When you take a warm shower, your pores open. Hot water temporarily disrupts the stratum corneum — the outer layer of skin — creating increased permeability. Research published in studies on dermal absorption has shown that the warm, wet conditions of showering can actually accelerate the uptake of chemicals on the skin surface into deeper skin layers. So showering doesn't just expose you to what's in your soap — it creates ideal conditions for maximum absorption.
How Much Are We Actually Talking About?
Let's run the numbers for a hypothetical person
who showers once every other day — a perfectly common and even dermatologist-recommended frequency. That's 182 showers per year.
At a conservative average of 7 grams of bar soap used per shower — consistent with usage studies on personal cleansing products — that person uses approximately 1,277 grams (about 2.8 lbs) of soap on their body alone over a year.
Now here's where it gets real. Lye constitutes roughly 7% of a finished soap bar by weight (before full saponification transforms it). If that lye came from a technical-grade source with a conservative 5% impurity rate (well within the 3–10% range documented for industrial-grade NaOH), the resulting soap contains approximately 0.35% impurities by weight from the lye alone.
Over the course of the year:
- Each shower deposits approximately 24.5 mg of potential lye-sourced contaminants onto the skin
- Over 182 showers: approximately 4,470 mg (4.47 grams) of those impurities contact your skin
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At a 60% skin absorption rate: approximately 2,680 mg (2.68 grams) of heavy metal-containing impurities absorbed into your body over the course of one year
That's 2.68 grams of trace heavy metals — including potential lead, mercury, iron, nickel, copper, and chlorides — absorbed into the bloodstream through the skin, one shower at a time, from a product marketed as natural or handmade soap.