Formaldehyde is used primarily to make urea-, phenol- and melamine-formaldehyde resins. Other large applications include polyacetal resins, pentaerythritol, methyl di-p-phenylene isocyanate (MDI), and 1,4-butanediol (BDO). Consumption of formaldehyde depends mainly on the construction, automotive and furniture markets. In the developed world, growth in demand will typically track gross domestic product (GDP) although it will be strongly correlated to the construction industry. Formaldehyde’s uses can lead to widespread exposure in downstream industries. For example, when formaldehyde is present in disinfectants, preservatives, and embalming fluid, worker exposure can occur. Although formaldehyde changes into other chemicals when urea-formaldehyde resins and concentrates are produced, decay may occur, causing workers in numerous industries including wood products and apparel manufacturer to be exposed to airborne formaldehyde when it off-gases from products manufactured with these resins.
Read more about it here: http://www.who.int/water_sanitation_health/dwq/chemicals/formaldehyde130605.pdf.