(615) 482-0862

A Mold Expert's Opinion

The Truth About Black Mold

Is all black mold toxic? The answer might surprise you. Let's separate fact from fiction.

By Zane Smith | September 6, 2022

You spot some black growth in your bathroom or basement. Your heart sinks. "Is that black mold?" you wonder, immediately thinking of the horror stories you've heard. Let's take a breath and talk about what's actually going on.

Is All Black Mold Toxic?

No. Not all black mold is toxic. There are over 100,000 known types of mold — and possibly 200,000+ species yet to be discovered. Many of them appear black in color. The specific strain people usually worry about is Stachybotrys chartarum, which is indeed toxigenic (meaning it produces mycotoxins). But here's the key takeaway:

It is impossible to tell by color alone which molds are toxigenic. The only way to identify mold species is through laboratory testing.

This is why we always recommend the same approach regardless of color: assume all mold may be harmful and seek professional assessment. Not because we want to scare you, but because your family's health isn't worth the gamble.

What Actually Kills Mold?

The EPA recommends hiring a professional for any mold-affected area larger than 10 square feet. For small cleanups (like a patch on bathroom tile), here's what works — and what doesn't:

Why NOT to Use Bleach

Bleach does not penetrate porous surfaces — it kills surface mold but leaves roots alive

Bleach is toxic and produces harmful fumes

Mixed with ammonia, bleach creates deadly chloramine gas

The chlorine in bleach evaporates quickly, leaving behind water — which feeds mold growth

Note: Bleach is acceptable for small cleanups on non-porous surfaces like bathtubs, sinks, and glazed tile.

Better Alternatives

White vinegar and water solution (effective on most surfaces)

Hydrogen peroxide (3% solution — safe and effective)

Detergent and water solution (for non-porous surfaces)

Hypochlorous acid-based cleaners (professional-grade option)

Our Promise: No Cost, No Obligation

Found mold in your home? Don't panic, and don't try to handle it alone if the area is larger than 10 square feet. Call The Mold Guys for a free, no-obligation assessment. We'll tell you exactly what you're dealing with and what needs to be done — no scare tactics, no pressure.

Want to learn more about mold in general? Check out our comprehensive guide: What is Mold?