Cfrtjryk

(I know little science so please help me if I'm in the wrong place or if my question needs editing. I could use help with tagging, for example.)

If I can smell something then does that mean there are particles or chemicals in the air?

My question is motivated by some new window blinds that have been installed in my home. The blinds have a smell, which is most noticeable when the sun is shining on them. I am trying to work out if the blinds are emitting some chemical into the air. This question is my first step.

[This question is not the same as "How does the smell of a compound come about, and is it possible to define a smell?". This is clear from the title.]

Smell works because your nose detects substances in the air.

Everything you can smell is the result of a molecule carried by air interacting with complex proteins in the nose/mouth (smell and taste are related but taste copes with solids and liquids as well as volatile airborne stuff). We broadly understand how smell works but the exact details are often a complete mystery.

The key is that smell-sensing nerves contain some proteins with very specific sensor sites that can detect particular groups of substances when they "fit" into the site. Exactly how the sites translate the fit into nerve signals is often a mystery. But the point that matters for this question is that the stuff being detected has to be carried into the nose via the air (which means it has to be a gas or, possibly, a very small particle that is easily carried by air).

So, yes, smell implies there are chemicals or particles in the air. However, the nose is extremely sensitive to some chemicals and being able to detect the smell does not imply a problem (even nasties like hydrogen sulphide are detectable by smell at below parts per billion concentration, hundreds of times below the level causing harm). Your blinds probably are emitting something but it is most likely both harmless and will probably fade with time like the smell characteristic of a new car.

Definitively yes, as already described by another user.
I would point out that air conditions, such a temperature and humidity might trigger a kind of smelling sensation in many subjects. The so called "smell of coming snow" is likely an example. It is not related to your windows but I wanted to add this as a curiosity. Very very strictly speaking, smelling something doesn't implies specific molecules or particles are in the air.

Most definitely you are "smelling" a chemical (almost certainly a gas in this case), and many people have over sensitive inflammatory reactions to many "approved" chemicals in the environment (ie perfumes, fabric softeners, solvents, etc.), so you may have a reaction (like bronchial constriction) even though most people would not.