Research projects

German Environmental Agency, FKZ 3723 48 301 0, project duration 6/2023 – 5/2026

The consequences of climate change pose enormous challenges for urban regions in form of prolonged heat waves, heavy rain events with floods and droughts. Therefore, the model of the climate-resilient city is becoming increasingly important. At this point, the principle of the “sponge city” makes a decisive contribution to a fundamental new way of handling with water by retaining rainwater, thus relieving the burden on sewage systems and also reducing the urban heat island effect through evaporative cooling. A mixed use of green roofs in connection with photovoltaic (so-called solar green roofs) complement each other particularly advantageously.

The project goals are, on the one hand, the development of an effective mix of policy instruments with which the blue-green infrastructure of a climate-resilient sponge city can be effectively implemented throughout in existing buildings. On the other hand, model solutions for green roofs are an important element of the blue-green infrastructure of a climate-resilient sponge city and should be developed.

The work packages WP 1 to WP 3 first summarize the state of knowledge and research on climate-resilient sponge cities. Thenpolitical instruments for implementing the necessary measures are identified. In addition, the socio-technical system of the sponge city is described in more detail and drivers and barriers to thetransformation into climate-resilient sponge cities are identified. This results in the 10 most important policy instruments for the implementation of the climate-resilient sponge city,with a focus on German small and medium-sized towns.

WP 4 presents the most effective green roof types for the sponge city and content-related criteria for a funding guideline and tender recommendations for solar green roofs It also gives recommendations for recycling-friendly sample roofs based on the using of building materials and the energy balance for the most important building types.

In the WP 5 led by Hydrotox, laboratory tests for 20 products/materials that come into contact with rainwater and are used in green roofs are tested according to CEN/TS 17459 in order to examine their ecotoxicological safety. A model of a green roof is replicated on a small scale in the laboratory and the infiltrated rainwater is examined for ecotoxicological effects. For comparison, the roof runoff water from the practical objects is tested.

German Environment Agency, FKZ 3721 37 305, project duration 10/2021 – 9/2024

The goal of environmental labeling with the Blue Angel is to convey product statements on verifiable and non-misleading information regarding the environmental aspects and to support products that cause less environmental impact. Eco-labels should also identify those products which comply with health and safety requirements, consumer safety and usability.

The development and selection of the award criteria of the Blue Angel must be carried out in accordance with the standard DIN EN ISO 14024: 2000 (Environmental labels and declarations - Type I environmental labelling - Principles and procedures) on the basis of sound scientific and technical investigations.

In order to ensure that the resources required for these in-depth investigations are used in a targeted and efficient manner, the work of the Jury Eco-Labelling are preceded by feasibility studies. These studies analyze the market situation and the differentiation of the environmental performance of products on the market in order to assess the, practicability and chances of success of a new eco-label.

Within the project, several award criteria for new eco-labels, e.g. for organic growing media (garden soil), are being developed and discussed and approved with the concerned stakeholders. In addition, existing eco-labels, such as DE-UZ 17 for compostable plant pots and DE-UZ 13 for deadening litter used in winter services, are being revised.

German Environmental Agency, FKZ 372 465 709 0, project duration 8/2024 – 9/2027

Screening tests from the OECD 301 series and OECD 310, which are used to determine the ready biodegradability, are considered to possess an equal level of reliability in their outcome, although they have significant methodological and historical differences. With the further development of these tests, less frequently used test systems could be dispensed, and the basic conditions of the remaining test procedures could be better standardized. This would also improve the comparability of the test results between substances. The aim of the project is to examine the possibility of merging and improving the existing OECD test guidelines for testing the ready biodegradability of chemicals. To this end, a proposal for a consolidated test design for testing ready biodegradability will be developed. In a second step, an international round robin test with at least 10 qualified GLP laboratories will be organised, realised and evaluated.

In work package (WP) 1, the literature study from the previous project (Gartiser et al., 2017, 2023) will be updated and supplemented and the basic conditions of the various screening tests according to OECD 301 and OECD 310 will be systematically compared.

In WP 2, a proposal for a consolidated test design for testing ready biodegradability, based on OECD 301 or 310, will be developed. The existing measurement devices for determining the endpoints DOC, O2 consumption and CO2-evolution are considered. In addition, recommendations on the origin, characterization and pretreatment of the inoculum, the use of additional control approaches, the minimum number of parallel approaches in degradation tests, the number of measurements and the validity criteria are to be developed. The intended volumes of the test vessels are also to be checked and standardized.

In WP 3, the study plan for the round robin test (WP 4) will be developed. In coordination with the German Environment Agency, three test substances and one reference substance will be selected for being parallel tested in the newly developed consolidated test and the previous standard test. Suitable GLP laboratories from the OECD member states (Europe, USA, Japan, etc.) are being proposed and binding templates for documenting the study process will be developed.

AP 4 includes the organization, realisation and evaluation of an international round robin test with at least 10 GLP laboratories from different OECD countries. The participating laboratories will receive compensation for their expenses. Approximately 60 individual tests with three replicates each will be carried out. The evaluation is carried out using descriptive static methods and in accordance with DIN ISO 5725-2 and ISO/TS 5594 (ring test statistics). In addition, an international workshop on the project results and the draft OECD test guideline of the consolidated test will be organized and carried out in the first quarter of 2027.

UBA, FKZ 3719 37 3020, Laufzeit 5/2019 – 4/2022

The project aims at contributing to the harmonization of ecotoxicological test methods for construction products to implement the life cycle requirements of the Construction Products Regulation. In a previous project, recommendations for a test battery for the ecotoxicological assessment of the environmental compatibility of construction products for outdoor use (UBA texts 74/2016) have been developed. These have been taken into account in the Technical Rule CEN / TR 17105, which in the future will be converted into a Technical Specification (TS) for obtaining a more binding status. For the purpose of quality assurance and validation of the draft guideline, a round table interlaboratory test shall be organized and carried out in accordance with the specifications of DIN ISO 5725. Initially, about 30 construction products will be selected and the available data will be screened for inorganic and organic parameters. From at least 10 of the striking products aqueous eluates will be produced and tested in the bioassays. Hereby, plate-like or monolithic products are eluted in the "dynamic surface leaching test" (DSLT) according to DIN CEN / TS 16637-2), granular products by means of percolation test in upward flow (DIN CEN / TS 16637-3). The eluates are subjected to a basic chemical and/or more comprehensive analysis and full ecotoxicity tests. For the interlaboratory test a minimum number of 12 participants is envisaged.

As a second task, proposals for the integration of the methods into the award criteria of the "Blue Angel" for three product groups will be developed. For this purpose, products which could supplement the existing product range of the Blue Angel will be analyzed in the test battery. Suitable product categories may include e.g. earth-contacting building sealings, facade coatings or roofing materials (bitumen, foil or liquid sealings). For these construction products, suitable award criteria for ecotoxicological assessment should be developed. The results of the overall project will be presented at an international workshop in February/March 2021 at the German Federal Environment Agency.

German Federal Environment Agency, FKZ 3718 65 410 0, project duration 09/2018 - 09/2021

Screening tests of the OECD 301 series and the OECD 310 are used for testing of ready biodegradability and for the identification of persistent, bioaccumulating and toxic substances (PBT substances). Although these tests differ considerably in methodology and historical background, the test results are considered as equivalent. One goal of the project is to provide recommendations for further development and standardization of these tests in order to improve the comparability of the test results. Screening tests are considered stringent, but are based on very artificial test conditions. Therefore, only a positive result can be used to relieve a persistence suspicion. A negative result requires the application of OECD simulation tests, which allow the derivation of degradation half-lives and are carried out with more realistic substance and inoculum concentrations. However, these tests usually require the use of ¹⁴C-labeled test substances and are much more time and cost-intensive compared to screening tests. The project aims at contributing to close the existing gap between screening tests and complex studies through so-called "enhanced ready" tests.

In WP 1 (work package 1), a systematic comparison of the established test guidelines for determining ready biodegradability will be carried out while examining options for their harmonisation. For this purpose, in particular the experiences of the performing laboratories will be queried. The results will be presented and discussed in 2019 at an international one-day workshop at the Federal Environment Agency.

In WP 2, potential test substances intended for the practical investigations in AP 3 will be researched, which will be carried out to verify the conclusions on the persistence assessment. In particular, substances with an expected biodegradability of 20-40% or substances with low water solubility for which valid simulation studies are available should be included.

In AP 3, practical laboratory tests will be carried out with five substances selected in AP 2 in order to test the influence of the changed test conditions in "enhanced ready" tests. This includes in particular an extension of the test duration, the enlargement of the test vessels and the use of alternative inoculums. In addition, so-called combination tests with parallel determination of several endpoints (O2 consumption and CO2 development) will be carried out. In total, about 20 tests are scheduled.

In AP 4, proposals for the development of a test guideline for "enhanced ready biodegradation tests" will be developed.

In AP 5, the impact of the project results for the persistence assessment under REACH will be analyzed.

DIBt, project duration 1/2015 -04/2016

So far the requirements for construction products regarding health and environmental protection have not been harmonised in Europe. Therefore, the health and environmental safety of reactive fire protection coatings have to be proven within the framework of the general building authority approval according to Building Regulations B, Part 1 and the European Technical Approval Guidelines ETAG 018-1 or ETAG 018-2.

Currently, only the formulation of construction products is evaluated in the approval process according to level 1 of the “DIBt principles for evaluating the effects of construction products on soil and groundwater”. Since construction products can indeed contain critical ingredients that are released in contact with water, a concept for the leaching behaviour and evaluation of leachates with ecotoxicological methods was developed in this project.

For this purpose, specimens of three representative reactive fire protection systems with different compositions according to ETAG, consisting of a steel corpus, a primer, an adhesion promoter, the reactive component and optionally a top coat were prepared according to the manufacturer's instructions. The fire protection systems of the type "X" are designed for all applications and thus may also be exposed to direct weathering. Subsequently, leaching tests were carried out with the selected test specimens according to DIN EN 16105 and CEN / TS 16637-2 and the eluates obtained were evaluated in the algae-, daphnia-, bioluminescence-, and fish-egg tests to determine their ecotoxicological effects. Additionally, umu-tests were performed to evaluate genotoxicity effects and the biodegradability of the organic ingredients of the eluates were determined.

The final report can be downloaded here.

German Federal Environment Agency, Project No. 54429, project duration 05/2015 – 03/2016

Data on biodegradability and persistence are, inter alia, required for the identification of persistent, bioaccumulative and toxic substances (PBTs) and very persistent and very bioaccumulative substances (vPvB substances) according to REACH Annex XIII. Results from ready biodegradability screening tests (e.g. OECD 301 A-F, OECD 310) allow a first estimate on potential persistency. However, only "readily biodegradable" substances are assumed as being "non-persistent". For the tests on inherent degradability (OECD 302 B and C) very strict criteria are used, which exclude them mainly from persistency evaluation in practice. Simulation tests (e.g. OECD 308, OECD 309) are considered as “gold standard" in persistency evaluation. These are performed with radiolabeled substances under more realistic conditions, but are much more complex and therefore more expensive. To reduce these costs so-called "enhanced screening tests" were proposed, which have an intermediate position between tests for ready biodegradability and the simulation tests and are intended to be exclusively used for persistency evaluation. The improvements proposed consist, inter alia, in an increase in the biomass and of the volume of the vessels as well as an extension of the test period to, for e.g. 60 days. However, no guidance on the borderlines to be set for "enhanced screening tests" exists.

A literature study was performed to review the applicability of established and new biodegradability tests for assessing persistence in the frame of PBT/vPvB assessments under REACH. Screening tests for ready and inherent biodegradability, proposals for enhanced ready tests as well as newly designed compartment-specific screening tests were analysed for strengths and weaknesses and proposals are made how to improve their performance and suitability for assessments of persistence. Although not in the focus of this study, some recommendations are also given for simulation tests (OECD 307, 308, 309) in the context of evaluating persistence. Recommendations focus on defining, standardising and optimising test conditions, on validity criteria and interpretation of test results. In the case of enhanced screening tests it is critically discussed which test modifications could be introduced without challenging the screening nature of the tests. Furthermore, specific issues such as non-extractable residues (NER) in tests with soil and sediment and substances difficult to test in standard tests (poorly water soluble, highly volatile or UVCB substances) are addressed.

The literature study has been published in the UBA-Texte series No. 10/2017.

German Environmental Agency, FKZ 3712 95 309, project duration 2012 - 2016

The European Construction Products Regulation (EU) No. 305/2011 allows Member States to adopt rules for evaluating the environmental impact of their buildings. The aim of the project was to develop recommendations for a test battery for the ecotoxicological assessment of the environmental impact of construction products for outdoor use, which contributes to the European harmonization of test methods. From a shortlist of 39 products 20 products were included in the ecotoxicological testing program. Monolithic and plate-like construction products were eluted in the Dynamic Surface Leaching test (DSLT) in accordance with CEN / TS 16637-2, granular products were eluated in the one stage batch test in accordance with DIN EN 12457-1. The eluates were examined in four aquatic toxicity tests (algae, daphnia, luminescent bacteria, fish eggs), a genotoxicity test (umu test) and in the respirometer test (OECD 301 F). Here, low to very high ecotoxicity was observed (up to a dilution factor of 1536).

In addition, a European round robin test with 17 participants and two construction products, was conceptually prepared, realised and evaluated compliant to ISO 5725. After excluding non-valid bioassays or those identified as outliers, the interlaboratory variability of the overall process for the ecotoxicological characterization of construction products was acceptable. The coefficient of variation of the 50% effective concentration (EC₅₀) was between 9-110% for the various tests and construction products. These values describe the variability of the entire, complex process flow from the leaching process to the sample storage up to actual biotest performance. Recommendations for planning and performance of ecotoxicity tests for the evaluation of construction products were elaborated and submitted to the CEN working group, responsible for European harmonization of leaching tests for construction products.

BMBF joint project FKZ 02WRS1279E, project duration 11/2011 - 03/2015

Tox-Box is funded as part of the BMBF-funded action "Risk assessment of new pollutants and pathogens in the water cycle (RiSKWa). Within the ToxBox project a harmonized testing strategy for an exposure and hazard-based risk management of anthropogenic trace substances is developed and described in a guidance document. In the context of the continuous improvement of analytical techniques, an increasing number of chemical compounds in drinking water or in raw water for drinking water abstraction is detected, for which sufficient scientific knowledge about the toxicological effects is lacking. The risk assessment is based on health-related indication values, following the HRIV concept. Although the HRIV concept denominates the relevant biological endpoints (genotoxicity, neurotoxicity, endocrine effects, germ cell damage) it does not mention any procedure for the experimental survey of the toxicological data. Hydrotox is implementing part of the work package "in-vitro genotoxicity tests with mammalian cell lines". For this, standardised mammalian test systems were adapted to the scope of work. The micronucleus test with the cell line V-79 (chinese hamster lung cells) is performed according to OECD 487 (2010), the Mouse-Lymphoma-Assay with the cell line L5178Y TK+/- according to OECD 476 (1997). Both in-vitro genotoxicity tests aim detecting possible mutagenic and carcinogenic agents. Further information Detailed information is available on the website of the ToxBox.

BMBF Integrated Project, FKZ 02WU1055, project duration 10/2009 - 4/2013

The aim of the BMBF-funded joint research project is to develop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR). Current ecotoxicological research usually involves a battery of bioassays to cover different toxicological endpoints (e.g. teratogenicity, genotoxicity, mutagenicity, Ah-receptor-mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression allow deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular toxic response. Gene expression profiles reflect the strategy how cells and organisms adapt or respond to a changing environment.