In Regard to the Classification of Ductless Fume Hood

Many laboratory professionals consider a fume hood to be a fume hood.If it has four sides and the font is made of glass, they call it a fume hood.

However, if you look closely, there are biosafety hoods, radioactive hoods, chemical hoods, environmental hoods, the list goes on.In chemical fume hoods, there are many special fume hoods that can safely accommodate various types of chemical hazards.Then you will see a very obvious appearance: fume hood with duct and fume hood without duct.

The ductless hood is a hero to users and laboratory managers.At the same time, for safety personnel, the ductless fume hood can be a headache.The advantages of ductless hoods are well known.They are flexible and adaptable, do not require plumbing, save space, etc.Their limitations are based on the (usually) chemistry behind carbon-based filters.

The Scientific Equipment and Furniture Association (SEFA 9-2010) Outlines tubesless hoods in this way.

Type I ductless fume hood

These types of hoods are usually small and provide control of only major hazardous chemicals.The most common applications include clinical or educational histology and pathology, slide staining, and other uses of bench chemical reagents.Filters can be general-purpose activated carbon or application-specific materials.This type of fume hood has no active chemical detection function and should not be used to handle hazardous chemicals.

Model II ductless fume cupboard

This kind of fume hood is what most people think of when they face the “ductless fume hood”.The various types of filter are determined by the chemical process occurring and their application is reviewed by the fume hood manufacturer.Only hazardous chemicals approved by the manufacturer can be used in DH II.These hoods have methods for detecting and communicating chemical permeates in addition to filtration to the operator.

Model III ductless fume cupboard

Quite simply, this type refers to a DH II with a backup filter.The description defining this type of fume hood is interesting.After chemical testing, the above backup filters are required to have the same type and efficacy.Efficiency refers to efficiency, not filter size and chemical capacity.The benefit of the DH III is that once the sensor detects contaminant penetration, this type of hood will remain stable long enough to allow time to replace the filter.

Summaries

Some experts say that certain types of ductless hoods cannot be compared with each other.It’s like comparing a wireless phone to a smartphone: neither device is hanging on the wall, but they do very different things.Some people look at the differences in terms of the laboratory and what type of hood is required.What is the lab doing?What is being used in the lab?What are the safety requirements for the laboratory?These problems are crucial for selecting the right ductless fume hood for laboratory safety.

Request a chemical assessment to determine the best ductless fume hood and filter for your application.