The Indoortron

Healthy Indoor Environments, a Challenge for Europe

an Interview done by Luk Vandaele, BBRI, Belgium

One of the research partners in clear-up is Dr. Dimitrios Kotzias. He is the head of the Chemical Assessment and Testing Unit of the Institute for Health and Consumer Protection (IHCP) at the Commission’s Joint Research Centre (JRC) in Ispra, Italy. He has a Ph.D. in chemistry and his research activities are focused on indoor air quality and exposure assessment for chemical compounds and mixtures. He has a long history in EU research; one of the recent projects was INDEX.

» Dr Kotzias, the INDEX project1 has set a milestone in the assessment of the exposure to pollutants in the indoor air. Can you sketch its importance?

In the past decades a large number of studies have indicated the presence of many chemical substances in indoor environments (buildings, homes). Their presence in indoor air is the result of infiltration of polluted outdoor air and of emissions from various indoor sources, such as building materials, activities of the occupants, consumer products, smoking, etc. The result of this situation is that there is an objective difficulty in regulating the presence of these substances in indoor air principally because of the absence of adequate hazard and risk assessment. Therefore an urgent need existed to develop a strategy for the identification of priorities in testing, assessment and regulation.
The INDEX project created a network of European leading scientists in indoor air pollution and the associated health impacts, and identified priorities for a Community strategy and action plan. INDEX assessed the existing knowledge worldwide on type and levels of chemicals in indoor air and the available toxicological information to allow the assessment of risk to health and comfort.
Based on the potential or estimated population risk caused by concentrations from indoor sources, toxicological properties including hypersensitivity for allergy and asthma, other known health effects and comfort, it was decided to define 14 chemicals of concern for the indoor environment and to proceed with the prioritisation of the compounds as follows:

1. High priority chemicals : Formaldehyde, Benzene, Carbon monoxide, Nitrogen dioxide and Naphthalene

2. Second priority chemicals: Acetaldehyde, o-, m- and p-Xylene, Toluene, Styrene

3. Chemicals requiring further research with regard to human exposure or dose response: Ammonia, d-Limonene, a-Pinene


» What can we learn from INDEX and how is it affecting the work in clear-up?

The INDEX project has indicated a number of compounds (Group 1-3), which are evaluated as key indoor air pollutants. These compounds significantly affect human health and comfort in confined spaces. The clear-up project aims at the development of sustainable approaches to manage a healthy indoor environment. This means that the project should among others provide solutions to reduce and/or eliminate such chemical compounds in indoor environments.

» What do you expect as achievements from clear-up?
What are the ambitions?

An achievement would be the development of innovative, low cost and consumer friendly photo-catalytic materials, which will be able to eliminate hazardous air pollutants by photo-mineralisation. The ambition is to be able to use these materials in indoor environments activating them by visible light, a challenge which is still open.

 » What experiments will be carried out in the INDOORTRON?

We will study the fate of priority air pollutants, in particular of volatile organic compounds (VOCs) in indoor environments by applying new and innovative photo-catalytic2 construction materials provided by our partners in the clear-up project. Emphasis will be given to testing the photo-catalytic efficiency of these materials under real-world setting conditions, i.e. under defined conditions of temperature, humidity and illumination (visible light). The experiments in the INDOORTRON facility will contribute to the in-depth knowledge of the mechanisms of the photo-degradation of organic and inorganic compounds and the development and optimization of industrial formulations as photo-catalytic materials.

1 Critical Appraisal of the Setting and Implementation of Indoor Exposure Limits in the EU (

2 See clear-up NEWS 1, September 2009 (jump to article)

The INDOORTRON is a 30 m3 walk-in environmental chamber permitting precise control of parameters such as temperature, relative humidity and the air exchange rate. Only stainless steel, glass and “non-stick”  polytetrafluoroethylene (PTFE) polymer coatings were used in the airtight chamber to minimise pollutant adsorption and emission by the inner walls. Internal heaters/coolers and a surrounding insulated jacket enable the internal temperature to be maintained with a high degree of accuracy. Ceiling-mounted blowers and a series of fans mix the air and ensure an even temperature distribution. For experimental purposes, the INDOORTRON is filled with ultra-clean pre-dried “zero” air. Controlled humidification is achieved by steam injection into the dry airflow immediately before it enters the chamber. For more info, contact Dimitrios Kotzias at