Is sodium chloride really odourless? If yes, what do I smell? I just had to read some general descriptions of sodium chloride and it was always classified as odourless (e.g., by Wikipedia). However, large amounts of table salts (around 1 kg) have a clearly perceptible odour to me. By table salt I mean salt sold for the purpose of cooking – I have not been taking notes or making experiments, but as I had the experience on dozens of different occasions, I would guess that the salt does not need to be iodised.

If I had to describe the smell, I would first say salty. It’s somewhat similar to the smell of the seaside, but the latter is much richer and has additional components. From the ten smell categories proposed here, only sweet and chemical fit somehow. It also has something of petrichor.

Is the classification as odourless just an approximation or do I smell additional ingredients (such as iodide) or impurities that cause table salt not to be pure sodium chloride? In the latter case: What causes the odour?
Since odour is generally coming from vapour / gas form of a material, and NaCl has zero vapour pressure, it should be odourless.
However: 


Moving around solid materials, dust, small particles can fly around that can be dissolved in the nose and interact with the odour sensors. 
You almost always have something else together with salt. And if it is not pure, you cannot be sure what makes the odour, the salt or the impurity. Eg. sea salt often contains remains of algae.