The need for chemical fume hoods to provide adequate air quality that protects personnel health will continue to increase with innovation and manufacturing. Polypropylene fume hoods are generally divided into two categories:

1) Ductless fume hoods

2) Ducted fume hoods

The ductless fume hoods use a variety of carbon filters to trap hazardous fumes/vapors and thereby provide personnel protection in the workspace. In some cases, the carbon filter can be stacked with a supply-side, high-efficiency particulate air (HEPA) filter and thereby provide product protection from particulate contamination.

The ducted fume hoods use a duct system that vents hazardous fumes/vapors outside the building and thereby provide personnel protection in the workspace. The two main types of duct material are Type 1 polyvinyl chloride (PVC) and Type 316 stainless steel. The ducted fume hoods may need a dedicated exhaust fan to vent the hazardous fumes/vapors if the central exhaust system of the building cannot provide adequate airflow.

The application and safety considerations of fume hoods can best be illustrated by the handling of volatile organic compounds (VOCs) and fixative reagents in histopathology labs as indicated below.

The impact of VOCs (e.g., xylene, ethanol, isopropanol which metabolizes to acetone) on indoor air quality and personnel health is widely documented. For example, xylene exposure during routine working conditions causes a 2-fold increase in DNA damage and a 3-fold increase in karyolitic/apoptotic cells in histopathology lab technicians versus controls 1. Moreover, complex mixtures of VOCs increase the risk of sick building syndrome irritating the eyes, skin, respiratory tract, etc and increase the risk of adversely affecting personnel health2.

The impact of fixative reagents (e.g., formaldehyde, glutaraldehyde, and osmium) on indoor air quality and personnel health is also widely documented. For example, formaldehyde exposure during routine working conditions causes DNA-protein crosslinking which is the dominant mechanism of DNA damage associated with formaldehyde exposure. In addition, formaldehyde causes an increase in various genotoxicity markers found in both lymphocytes and buccal cells of histopathology lab technicians versus controls3. These genotoxicity markers include micronuclei (a biomarker for chromosome breakage or loss), nucleoplasmic bridges (a biomarker for chromosome rearrangement and poor DNA repair), and nuclear buds (a biomarker for the elimination of amplified DNA).

References:

1. De Aquino T. et al: An. Acad. Bras. Cienc 88 (1): 2016.

2. Cipolla M. et al; Int J Environmental Research Public Health 14(6): 609, 2017.

3. Ladeira C. et al: Mut Res/Gen Tox and Env Mutagenesis 721 (1): 15, 2011..