PORKKA BLUE – for Refrigerated Appliances

Porkka BLUE Antimicrobial Light

PORKKA BLUE is a blue light system, an accessory for Porkka Cold and Freezer rooms and Professional Cabinets. The PORKKA BLUE light photon disinfection system deploys blue light whenever the targeted space is not in use.

PORKKA BLUE photon disinfection luminaires are harmless to humans and materials. The lights are typically controlled either manually (with a switch) or automatically (with a timer).

Effective Blue Light

Blue light has been shown to destroy bacteria, moulds and yeasts with high efficiency in all our cold rooms for sale, as well as our commercial freezers and refrigerators. Its power can be enhanced to also destroy viruses and endospores.

The antimicrobial properties of blue light have been known for decades, but only the latest developments in LED technology have made disinfection with blue light a cost-effective solution.

Enhanced Features

Catalytic coating is available as an option for Porkka Cold Rooms. It enhances the effects of blue light. Blue light + Catalytic coating combined is effective on all micro organisms, including viruses and spores. Reaction also destroys odours and VOCs from the air.

Blue light without the Catalytic coating is effective on all bacteria, fungi, mould and yeast. Blue light also penetrates biofilm.

NOT using UV wave length light

The Finnish Radiation and Nuclear Safety Authority (STUK) tested 1) PORKKA BLUE technology of photon disinfection luminaires in its laboratory. The test report shows that the radiation is non-ionizing.

The effects of blue light on human cells have been tested at high dosages. Even doses ten times higher than that used in PORKKA BLUE’s solutions caused no harmful or toxic changes to the cells 2).


The ability of blue light to destroy microbes is based on its ability to energize naturally light-sensitive compounds inside the microbe so that they start producing reactive oxygen species (ROS) inside the cell. Oxygen species are extremely reactive and destroy vitally essential components of the cell (cell membrane, DNA/RNA, protein structures).

The University of Eastern Finland (UEF) has studied 4) the effect of blue light in cold food storage temperatures to several bacteria and fungi (ATCC Cultures): within 24 hours all pathogens are inactivated.


  • Scientific threshold value of antimicrobial effects is decrease of 3 log cfu/ml or more (10000 units > 10 units) 5)
  • Independent scientific studies show PORKKA BLUE light has a clear antimicrobial effect, eg. Salmonella enterica up to 3,5-5,6 log cfu/ml
  • PORKKA BLUE effect is often comparable to UV light.
  • The complex structure of the food makes it more difficult to inactivate microbes.
  • PORKKA BLUE light is especially suitable for colorful food stuff.

Extremely well-studied 3)

1) Led Tailor 12 April 2017.
2) Liebmann et al., 2010. Blue-Light Irradiation Regulates Proliferation and Differentiation in Human Skin Cells. J Invest Dermatol. 2010 Jan;130(1):259-69. doi: 10.1038/jid.2009.194. Read a study: Blue light alone can eliminate MRSA without inactivation of human keratinocytes (https://link.springer.com/article/10.1007%2Fs10103-019-02774-9)
3) More than 1,800 scientific publications. 03/2020 PubMed service with search terms: “antimicrobial” and “blue” and “light”
4-5) to be published 2020


The best solution for surface disinfection in refrigerated appliances and similar used in, for example, the following environments: nursing homes, schools and day care centres, dental clinics, veterinary clinics, grocery stores, restaurants and kitchens, supermarkets, food industry, indoor air quality, issue sites, refrigerated waste material storages, scientific and medical cabinets in hospitals, laboratories and cleanrooms.