Formaldehyde is also given off by many common office products. Synthetic fibers in rugs and furniture, and urea foam insulation can give off small amounts of formaldehyde. Confined Spaces A confined space is an area with small openings for a worker to enter and exit and is not designed for regular work. Examples of confined spaces include manholes, sewer digestors and silos, tunnels, pumping stations, and utility vaults. There are many hazards in confined spaces.
Workers can become unconscious and die from a lack of oxygen.
At other times, there may be too much oxygen, or other chemicals that can catch fire or explode. Poisonous gases and vapors, such as hydrogen sulfide or carbon monoxide, may also build up in a confined space. Confined spaces can also pose physical hazards. They can be very hot or cold. Such an area can be very loud.