The Toxic Substances Control Act is the principal US law governing industrial chemicals. Over the past three and one half decades, it has become clear that a considerable toxicological information gap exists about chemicals in commerce. The current provisions of the US TSCA law have failed to fill, and perhaps even exacerbated, that gap.
For at least the past 5 years, bills have been introduced before the US Congress to reauthorize TSCA. Filling the toxicological information gap has been one of the driving forces for this call for substantial change. This article describes efforts to modernize TSCA, with an emphasis on the new provisions that would be put into place if the legislation became law. The article shows that only by implementing a “replacement-first” strategy – a strategy that is not currently incorporated into TSCA reauthorization efforts – can TSCA modernization efforts potentially fill the toxic data voids.

The first deadline for REACH registration has passed and registration data for the first set of substances are now public. According to ECHA, 4,599 substances have been registered so far, and the corresponding dossiers of many of them are now partially available in a public database. A sample of 400 records was randomly selected and analyzed with regard to reproductive and developmental toxicity. Most dossiers do not follow the strict requirements in the official guidelines, and some dossiers lack some very basic information. A broad variety of existing data is used, and the read-across opportunity is very much exploited. Surprisingly, a number of in vivo tests have been performed already, apparently for REACH purposes, in spite of the legal requirement to make a public proposal and wait for authorization by ECHA. The number of animals used so far, plus the number of animals that will derive from testing proposals of the first REACH deadline, is very high; it may add up to 1.6 million animals just to accomplish reproductive and developmental toxicity endpoints if the data collected from 400 dossiers are extrapolated to the total number of registered substances. In vitro tests are completely absent, even though there are many tests that may be used to complement either read-across strategies or partially reliable existing data. It is recommended, in the spirit of REACH, to protect human health through an in-depth assessment of the chemicals and simultaneously, to promote the use of in vitro alternatives.

Genotoxicity tests are essential to identify compounds that have a potential to compromise not only the environment but also human and animal health, including compounds that increase the risk of cancer. At present, no single test is capable of detecting all types of genotoxic effects; therefore a battery of in vitro and, if positive, in vivo tests is necessary to determine the genotoxicity of a substance. However, the respective specificities of current assays have been criticized for their high percentage of false positive results. We recently published an automated version of the “Fluorimetric detection of Alkaline DNA Unwinding” (FADU) assay for measuring DNA strand breaks in human peripheral blood mononuclear cells or in cell lines. Using this new technology we show detection of DNA strand breaks in cells treated with several compounds known to induce DNA strand breaks by various mechanisms. We also tested toxic compounds that were not expected to induce DNA strand breaks; these were negative in the assay as expected. Finally, we included zinc oxide nanoparticles of high production volume to explore further fields of potential FADU applications. The main advantages of this assay are high reproducibility, easy handling, lack of operator bias, high-throughput, speed, and low cost.

The search for alternatives to the use of fetal bovine serum (FBS) in cell and tissue culture media has become a major goal in terms of the 3R principles in order to reduce or to avoid harvesting of FBS from bovine fetuses, and, in terms of Good Manufacturing Practice (GMP), to ensure safe and animal product-free conditions for biomedical tissue engineering and (adult) stem cell therapy, respectively. In the present study, we investigated the feasibility of using platelet lysates (PL) as a substitute for FBS, based on the fact that most of the potent mitogenic factors present in serum are derived from activated thrombocytes.

Platelet lysates were obtained from outdated human donor platelet concentrates. Methods were established to activate human donor platelets in order to achieve a maximum yield of platelet α-granule growth factors. Platelet lysates were successfully introduced to grow and maintain anchorage-dependent and -independent human and animal cell lines. For cell culture experiments, cells were either grown in culture media supplemented with 10% FBS, 5% PL, or under serum-free conditions. Growth experiments, viability assays, and platelet lysate-induced activation of ERK1/2 mitogen-activated protein kinase revealed platelet lysates as a valuable alternative to FBS in cell culture media.

The 3Rs – Replacement, Reduction and Refinement – have become increasingly important in designing animal experiments. The Pavlov sling is thought to be a non-invasive method to restrain dogs for examinations. The aim of our study was to investigate whether laboratory Beagle dogs that had been trained to tolerate restraint by a Pavlov sling are stressed by this procedure and, furthermore, to analyze their behavior during this period. Five male and five female Beagle dogs were used, each three years of age. Animals were restrained in the Pavlov sling for 30 min on six days with an interval of at least two days. The following behaviors were recorded every minute for each session: postures of body, head, and ears, as well as state of eyes, tail, legs, and mouth. Additionally, the animals were observed for the occurrence of particular stress signs, including body shaking, sweating of the paws, increased saliva production, piloerection, blinking of eyes, snout licking, yawning, and panting. As an indicator for stress, salivary cortisol levels were measured before, during, and after each session. Our results show that for most behavioral parameters, e.g., body, leg, head, tail, and ear posture, the frequency of changes between different behavior patterns, as well as cortisol concentration, were not influenced by restraint in the Pavlov sling. Therefore, the Pavlov sling does not seem to be perceived as a stressful situation by the Beagle dogs. Our study demonstrates that under certain conditions the use of the Pavlov sling in trained dogs can substitute for more ordinary methods of immobilization, e.g., the use of narcotics.

Dogs are sometimes referred to as “man’s best friend” and with the increase in urbanization and lifestyle changes, dogs are seen by their owners as family members. Society expresses specific concerns about the experimental use of dogs, as they are sometimes perceived to have a special status for humans. This may appear somewhat conflicting with the idea that the intrinsic value of all animals is the same, and that also several other animal species are used in biomedical research and toxicology. This aspect and many others are discussed in an introductory chapter dealing with ethical considerations on the use of dogs as laboratory animals. The report gives an overview on the use of dogs in biomedical research, safety assessment and the drug developmental process and reflects the discussion on the use of dogs as second (non-rodent)species in toxicity testing. Approximately 20,000 dogs are used in scientific procedures in Europe every year, and their distinct genetic, physiological and behavioral characteristics may support their use as models for e.g. behavioral analysis and genetic research. Advances in the 3Rs (Replacement, Reduction and Refinement of experiments using dogs) are described, potential opportunities are discussed and recommendations for further progress in this area are made.

Development of improved communication and education strategies is important to make alternatives to the use of animals, and the broad range of applications of the 3Rs concept better known and understood by different audiences. For this purpose, the Center for Alternatives to Animal Testing in Europe (CAAT-Europe) together with the Transatlantic Think Tank for Toxicology (t4) hosted a three-day workshop on “Teaching Alternative Methods to Animal Experimentation”.
A compilation of the recommendations by a group of international specialists in the field is summarized in this report. Initially, the workshop participants identified the different audience groups to be addressed and also the communication media that may be used. The main outcome of the workshop was a framework for a comprehensive educational program. The modular structure of the teaching program presented here allows adaptation to different audiences with their specific needs; different time schedules can be easily accommodated on this basis. The topics cover the 3Rs principle, basic research, toxicological applications, method development and validation, regulatory aspects, case studies and ethical aspects of 3Rs approaches. This expert consortium agreed to generating teaching materials covering all modules and providing them in an open access online repository.