Compressed air
Compressed air is a combination of under pressure gases that are squeezed into a can. With computers and electronics, compressed air is the preferred method for removing dust and dirt from sensitive electronics. The picture shows an example of a typical compressed air can used to clean computer components. In this example, you would point the nozzle of the can in the direction you want the air to be blown and then squeeze the trigger.
When cleaning anything with compressed air, make sure that the can is in an upright position. If you tilt the can sideways or upside down, it is likely that some condensed air (liquid) can spray onto the electronics. This liquid is freezing, due to rapid decompression when it leaves the can and in this form, it can damage electronics, potentially causing them to fail. If it comes in contact with your skin, it can cause damage to your skin and can be painful. So take care when using canned air.
What is bitterant?
Bitterant is a chemical added to many compressed air cans that helps prevent anyone from inhaling the can by creating a bad taste and smell. This chemical is in small quantities and does not damage electrical or other sensitive parts.
Many people have posted online about the bitter taste of bitterant after spraying a keyboard with compressed air and then touching their mouth or food they are eating. If you use compressed air with bitterant on anything you frequently touch, use a damp cloth afterwards to wipe away any potential residue. You can also still find compressed air cans online that do not contain bitterant.