HACCP
[Abbr. for hazard analysis and critical control points] - A preventive system intended to ensure food safety from manufacture to the consumer.
H
HDPE
[Abbr. for high density polyethylene] - This thermoplastic polymer has a high resistance to acids, alkalis and chemicals.
Hepatitis
Hepatitis is the medical term for an inflammation of the liver which can be caused both by hepatitis viruses as well as by other pathogens such as bacteria and parasites. Of the classic viral hepatitis types, the Hepatitis B infection is the most common. Transmission, as with the HIV virus, is via the direct exchange of bodily fluids. With direct exposure, the viruses in question have a low-to-medium UVC-resistance.
herbicide
Weed killer.
Herpes simplex
Caused by the herpes simplex virus, herpes is the most common infectious disease of the skin. Although usually occurring as lip herpes (‘cold sores’), other parts of the skin can also be affected. To date, there are no curative treatments for herpes simplex infections, nor does the organism develop an immunity to the virus. With an average lethal dose (LD90) of 5 mJ/cm2, herpes simplex viruses exhibit a relatively high UVC sensitivity in laboratory trials.
HIV
[Abbr. for human immunodeficiency virus] - Belonging to the family of retroviruses, the HIV virus causes the well-known immunodeficiency disease AIDS. Around 100 to 120 nm in diameter, the virus is surrounded by an envelope. Statistically speaking, around 90% of the infections occur if people get transfused with HIV-positive blood, with transmission via bodily fluids being a possibility. Investigations by Henderson et al. revealed the virus to be extremely resistant to UVC radiation.
Hg
Chemical symbol for mercury.
humanopathogenic
Med. term meaning “causing disease in humans” - see pathogenic.
hydrogen bond
Hydrogen bonds are electrostatic and weak in nature compared to other bonds. Through the attractive force of differently charged atoms contained in the molecules, quite specific 3D structures form e.g. in the proteins or DNA.
hydrogen peroxide
Chem. symbol H2O2 - Like ozone, hydrogen peroxide is a strongly-oxidising agent, and is therefore used for bleaching and disinfection purposes. Hydrogen peroxide has an especially corrosive effect in vapour form.
hyphae
Hyphae (sing. hypha) are microscopically small, long, very thin, branching fungal filaments which develop in all directions from a mould spore on a breeding ground. Hyphae are involved in both feeding and propagation (see conidiophores). A mass of hyphae is referred to as a mycelium.