subject: How Lab Fumes Hoods Make Laboratories Safer [print this page] In controlled environments such as chemistry laboratories, it is important to keep up a high level of safety. There are a number of things that can be worn to protect individuals that work with hazardous chemicals. Examples of these are masks, goggles, gloves, boots and protective lab clothing. Aside from these, there are also devices used to improve a laboratory's safety level. Such devices are laboratory fume hoods.
These hoods are placed inside laboratories as local ventilation devices. They are also used to limit exposure to dangerous dusts, fumes and vapors. If inhaled, some fumes may result to respiratory complications.
Laboratory fume hoods are enclosures with an air duct connected at the top area. The front area is also the working area where a partially open glass sash is located. Lab users perform their tasks by putting their hands through the glass sash opening. The area inside the glass sash is made of metal, glass and chemical-resistant plastic.
There are two general types of laboratory fume hoods. These are ducted and re-circulating hoods. They both work in a similar manner. Clean air enters from the sash opening and with the ducted fume hoods, the air is then expelled out of the building by fume ducts. Also, a built-in filtration system filters the air before releasing it back into the room.
Re-circulating laboratory fume hoods are often used for testing or educational purposes. It is advisable to use these at times when known and stable fumes are being generated. This is because the filtering medium only works with specific and known hazardous and noxious materials.
Ducted laboratory fume hoods are often used in a more industrialized setting. These are advisable when working with unknown and unstable hazardous and noxious materials.
There are pluses and minuses with regards to the two types of fume hoods. With re-circulating hoods, because the air is filtered back in the room, contaminated air is not pumped into the atmosphere. The need to install ducts is also eliminated. The minus would have to be the potential noise caused by the device's fan. Depending on frequency of usage, filters are also maintained and replaced. The ducted laboratory fume hoods also have pros and cons.
An advantage with this type is that hazardous fumes are 100% removed in the laboratory air. Because the ducts are situated far from the actual user, fan noise is no cause for concern. Ducted fume hoods are also relatively low-maintenance when compared to re-circulating ones. The biggest disadvantage with this type would have to be the fact that contaminated air is released in the earth's atmosphere.
Because of the major role played by laboratory fume hoods, safety routine inspections are done to ensure that the machines are always in top shape. Laboratory safety is so important that in the United States, a federal administration was created. Inspection and performance standards have been established by the OSHA or Occupational Safety and Health Administration to make routine check-ups easier.
Laboratory fume hoods are important lab devices. With them, laboratories are definitely made safer.
