BS EN ISO 15858: Human Exposure Limits to UV-C

Disinfection systems utilising ultraviolet C (UV-C) irradiation are becoming more and more common, but this increased usage can lead to an increased risk of harmful exposure to UV-C radiation.

UV-C exposure can lead to some unpleasant health issues, particularly in the skin and eyes, and it can even aggravate some pre-existing conditions. Given a long enough exposure time, even a lower power source of UV-C radiation can be hazardous. Because of this, it’s important to understand what UV-C exposure limits are and how long it takes for a UV-C system to meet or exceed that limit.

What is the BS EN ISO 15858?

BS EN ISO 15858 is an international standard that provides minimum human safety requirements for UV-C exposure. It applies to almost any system that uses UV-C emitting lamps: the only exception is UV-C products used in water disinfection. The standard requires familiarity with BS EN 14255-1, which contains guidance on measuring UV exposure as well as guidance as to the equipment that may be required.

Manufacturers can use this standard to determine how long it takes for their UV-C product to meet or exceed the limits in the standard during use. Organisations using UV-C systems in the workplace can use this standard to check that UV-C safety limits are not exceeded in areas where UV-C light is used.

What information does the BS EN ISO 15858 standard provide?

The standard is primarily informative. It provides explanations and brief guidance on the following:

Terms and concepts related to UV-C.
UV-C penetration through transparent materials.
Reflection of UV-C.
Personal protective equipment (PPE) recommendations for cases where the exposure levels exceed the maximum.
Safety training of personnel.

The standard provides more in-depth information about maximum UV-C exposure times for a various degrees of irradiance (irradiance in this context is UV-C radiation power over an area, usually measured in W/m²) and a brief outline of the measurement process for threshold limit values, which is based on the standard BS EN 14255-1. The measurement process requires repeated readings taken at multiple orientations. This allows the assessor to build a comprehensive report of UV-C exposure in any given area.

Written by James Tolmie March 7th 2022

James is a laboratory scientist with a focus on product testing. He has a degree in English Literature & Creative Writing Editing and, as a freelance copy editor, he gained experience in editing and proofreading scientific papers and blog posts. He developed his product testing skills working as a Mastering Technician for over two years. During this time, James was part of a research and development team, testing new products and software and regularly reporting findings to key stakeholders. Alongside this, he maintained an archival database of nearly 3,000 customer projects and associated data, and was part of a small team of auditors responsible for ensuring that the company continued to meet the requirements of the ISO standards for which it was accredited.

At Test Labs, James designs and constructs bespoke rigs and devices built to meet customers’ specific product testing needs or the requirements of existing national and international standards. He also developed, from the ground up, a custom database for maintaining and monitoring Test Labs’ comprehensive selection of laboratory equipment and testing equipment. Finally, James uses his copy-editing experience to write and edit reports for customer’s studies as well as blog posts for the Test Labs website.