Like many chemicals, formaldehyde is not clearly visible, although, at times it might have a pungent aroma. It is used for treating various textiles like curtains, cushions and sofas. It may also be present in pressed lumber such as particle board or plywood. Formaldehyde can also be found in certain fuel burning appliances and glues.
So, what can we say about its effect on our health? Should we be concerned? Formaldehyde is a known carcinogen with the worst health risks being cancer particularly of the upper throat. Lesser symptoms from formaldehyde exposure are: respiratory problems, fatigue and allergy like symptoms (although this can be caused by many other things). It is important to note, however, that there is not much known about how much a person needs to be exposed to formaldehyde and for how long before it poses a health risk.
If you are concerned about this chemical being found in your home, its good to know that there are materials available that do not contain it. Research an item before you purchase it to make sure formaldehyde has not been used.