This sense of smell is important in the enjoyment of food, the attraction of one person to another, and in evaluating the cleanliness of our surroundings. What may be a pleasant odor in one context may be revolting in another. The aroma wafting from a fresh loaf of bread or a fresh pot of coffee carries a heavenly message to the person getting up from bed, while the lingering odors from cooking or smoking are certainly not welcomed by everyone. Although one odor may seem more pleasant than another, virtually all odors become unpleasant when perceived in high concentrations. Whereas words like aroma and flavor leave a positive impression, odor somehow leaves the feeling that it is an undesirable scent.
Scientists use the word malodor when they mean an undesirable scent.
Malodors can signal poor, and sometimes unsafe conditions. Many keep an open container of baking soda in the refrigerator to control food odors. Charcoal can be used to control odors in other parts of the house too. Infants recognize their mother by this smell. No amount of washing or perfumes can disguise this smell.