MCS Is Not An Allergy

MCS Is Not "Just an Allergy"

Here’s what it really is and why that matters.

Let’s clear something up:
Multiple Chemical Sensitivity (MCS) isn’t just an allergy. And when people treat it like one, it makes life harder and less safe for the folks living with it.

So, what is MCS?

MCS is a condition where everyday chemicals like air fresheners, detergents, perfumes, pesticides, and even some “green” products cause physical symptoms that can range from uncomfortable to completely disabling.

People with MCS aren’t just “being picky” or “not liking a smell.”
They’re reacting with:

• Brain fog and memory issues

• Dizziness or headaches

• Chest tightness, breathing issues

• Fatigue, heart palpitations, skin irritation, and more

These reactions aren’t psychological. They’re physical and often neurological or immune-related.

But wait… how is that different from an allergy?

Allergies usually show up on a test. They involve immune responses (like IgE antibodies) and tend to be predictable. MCS isn’t that clear-cut. You can have zero diagnosed allergies and still have MCS. It’s more like the body loses its ability to handle chemicals, a phenomenon researchers call TILT (Toxicant-Induced Loss of Tolerance) [Miller, 2001].

Need an example?

Let’s say your friend is severely allergic to shellfish (I hope we know now that MCS is not an allergy 😉). Now, imagine the world constantly exposes them to shrimp. Every restaurant, every event, every Uber, every store, shrimp in the air, on the seats, on people’s clothes.

And every time they ask for help, they get this:

“It’s not bothering me.”
“It’s not that serious.”
“Just avoid it.”

That’s what it feels like to live with MCS, except it’s every day, and the “shrimp” is everywhere.

“I don’t smell anything, it's fine…”

This one comes up a lot. Here’s the truth:

• You don’t have to smell something for it to affect someone with MCS.

• Many fragrance chemicals (and VOCs) hang in the air, cling to clothes, and can stay on skin or fabric for days, even when the scent fades.

Source:

VOCs (volatile organic compounds) from fragranced products can linger in indoor air and trigger reactions at levels considered “safe” by industrial standards [Steinemann, 2016].

Why does this matter?

When we mistake MCS for “just an allergy,” we:

• Minimize the lived experience of people with it

• Fail to create truly safe, scent-free spaces

• Contribute to social isolation, especially in workplaces, healthcare settings, and public spaces

It’s not about being extra. It’s about staying upright. It’s about being able to function, participate, and exist without harm.

What helps?

Here’s what makes a big difference:

• Respect scent-free requests, no “just a little” sprays

• Use truly fragrance-free products (not just “unscented”)

• Wash off scent products before visiting someone with MCS

• Don’t assume it’s “just in their head”

• Ask: “Is there anything I can do to make this safer for you?”

Ready to Learn More or Help Create Safer Spaces?

Explore our free guides on fragrance-free hosting, low-tox dining, and supporting people with MCS.

Browse the Directory to find scent-free stays, shops, salons, and events.

Submit a Find you think belongs on the list.