1,767,213 research outputs found
fhaegner/Mak-h-ro: Mak-h-ro ABM v1.0.0
No full textFirst release of the macroeconomic agent-based model Mak-h-ro
Triethanolamine [MAK Value Documentation, 2016]
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of triethanolamine [102‐71‐6], considering the endpoints respiratory tract irritation and developmental toxicity.
Critical effect of triethanolamine is respiratory tract irritation (focal larynx inflammation). The previous MAK value of 5 mg/m3 is based on 5‐day and 28‐day aerosol studies in rats with a LOAEC of 20 mg/m3. A benchmark calculation gives a BMDL05 of 14,1 mg/m3. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. Based on this approach, a concentration of 4,7 mg/m3 for the work place air can be calculated from this BMDL05. Therefore the MAK value of 5 mg/m3 is retained.
As local effects are critical, Peak Limitation Category I is retained. At an excursion factor of 2, the allowable maximum concentration is still below the BMDL05.
NOAEL for fetotoxicity are 300 mg/kg bw and day in rats and 1125 mg/kg body weight and day in mice . Teratogenicity was not tested. Nevertheless, because the calculated margins between NOAEL and MAK value are very high, and alkylamines lack teratogenicity, there is no reason to fear damage to the embryo or foetus when the MAK value is observed. Therefore, triethanolamine is assigned to Pregnancy Risk Group C
MAK - Museum für angewandte Kunst : Sammlung online (Textilien und Teppiche)
No full textThe MAK's digital collection database is available to the public for both private and academic research purposes. Master data and image information on 230,000 objects from the MAK collection areas Asia, Design, Contemporary Art, Glass and Ceramics, Furniture and Woodwork, Metal and Wiener Werkstätte Archive, Textiles and Carpets, as well as the MAK Library and Art Leaf Collection can be accessed. A further 70,000 entries provide additional information on participating artists and executing companies.
The MAK Collection online is continuously expanded and updated. The long-term goal is to make the MAK's collection, only parts of which can be exhibited in the museum, accessible in its entirety on the World Wide Web
trans‐1,3,3,3‐Tetrafluoropropene [MAK Value Documentation, 2019]
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of trans‐1,3,3,3‐tetrafluoropropene [29118‐24‐9]. As the blood:air partition coefficient of trans‐1,3,3,3‐tetrafluoropropene is < 5, the increased respiratory volume at the workplace (see List of MAK and BAT Values, Sections I b and I c) does not have to be taken into account for the derivation of the MAK value. Even after extrapolation of 6‐hour exposure in the animal experiment to 8‐hour exposure at the workplace, the MAK value for trans‐1,3,3,3‐tetrafluoropropene of 1000 ml/m3 can be retained
Naled [MAK value documentation, 2018]
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) and the Pregnancy Risk Group of naled [300‐76‐5].
Naled is a cholinesterase inhibitor. In an 13‐week study in rats at 1 mg/m3 there was a 18% inhibition of the cholinesterase activity in erythrocytes. The calculated lower 95% confidence limit of the benchmark dose (BMDL) for a 30% inhibition, which is regarded as not adverse, was 2 mg/m3. A MAK value of 1 mg/m3 was established for the inhalable fraction. It is now lowered to 0.5 mg/m3 taking into account the increased respiratory volume at the workplace (see List of MAK and BAT Values, Sections I b and I c). Since a systemic effect is the critical effect, Peak Limitation Category II is retained and the default excursion factor of 2 confirmed.
For rats, the NOAEL for developmental toxicity was 8 mg/kg body weight and day. Naled was assigned to Pregnancy Risk Group C because the difference between the MAK value and the NOAEL scaled to a concentration in the workplace air was sufficient. There are no new data on developmental toxicity. This classification is retained since now the difference to the MAK value is twice as high
2,3,3,3‐Tetrafluoropropene [MAK Value Documentation, 2019]
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of 2,3,3,3‐tetrafluoropropene [754‐12‐1]. As the blood:air partition coefficient of 2,3,3,3‐tetrafluoropropene is < 5, the increased respiratory volume at the workplace (see List of MAK and BAT Values, Sections I b and I c) does not have to be taken into account for the derivation of the MAK value. Moreover, the extrapolation of 6‐hour exposure in the animal experiment to 8‐hour exposure at the workplace does not need to be applied because the effect is much more dependent on the concentration than on time. The MAK value for 2,3,3,3‐tetrafluoropropene of 200 ml/m3 can therefore be retained
Trimethylamine : MAK Value Documentation, 2016
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of trimethylamine [75‐50‐3] of 2 ml/m3, considering the endpoints local and systemic toxicity as well as developmental toxicity. Available publications are described in detail. Daily exposure of rats to trimethylamine for 14 days resulted in inflammation of the respiratory epithelium at 74 ml/m3, the lowest concentration tested. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. According to this approach, the MAK value would have to be lowered to 1 ml/m3. However, several data show, that the previous MAK value can be retained. Workers reported no irritation at 5 ml trimethylamine/m3. In addition cyclohexylamine and dimethylamine with a MAK value of 2 ml/m3 are used as a read‐across due to similar alkalinity and RD50 values, and in a recent volunteer study a NOAEC of 2 ml cyclohexylamine/m3 is found. The MAK value will also protect from possible blue hazy vision which is caused by other tertiary amines since trimethylamine is assumed to be less effective than N,N‐dimethylethylamine with a MAK value of 2 ml/m3. The assignment is to Peak Limitation Category I, because local effects are critical, and the excursion factor of 2 is confirmed. Developmental toxicity studies with trimethylamine show that damage to the embryo or foetus is unlikely if the MAK value is observed, and the assignment to Pregnancy Risk Group C is retained
MAK-Bibliothek und Kunstblättersammlung
No full textThis text presents the actual status of reappraising the history of the MAK Library and Works on Paper Collection and of the provenance research concerning its acquisitions since 1933. It discusses two cases of works on paper that were looted during the Nazi era and recently revealed. The article closes with an outlook on further research projects.Dieser Text berichtet über den aktuellen Stand der Aufarbeitung der Geschichte der Bibliothek und Kunstblättersammlung des MAK und der Provenienzforschung zu deren Erwerbungen seit 1933. Zwei Fälle von in der NS-Zeit entzogenen Kunstblättern, die in den letzten Jahren recherchiert wurden, werden dargestellt. Mit einem Ausblick auf künftige Forschungsvorhaben schließt der Beitra
Glycerin [MAK Value Documentation, 2016]
No full textThe German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the work place (MAK value) of glycerol [56‐81‐5], considering the endpoints irritation of the respiratory tract and developmental toxicity.
Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. However, examination of the study results showed that this approach does not apply for glycerol, because glycerol is not an eye irritant and the minimal to slight metaplasia of the squamous epithelium of the larynx seen in rats at 662 mg/m3 with glycerol aerosol is not interpreted as adverse. The response does not increase with the exposure duration. Therefore, the MAK value is raised to 200 mg glycerol/m3 for the inhalable fraction.
Peak Limitation Category I for local effects with an excursion factor of 2 is retained, as the effect is hardly concentration‐dependent, a sensory irritation is not known, and glycerol is, if at all, only slightly irritating to the eye.
After scaling the oral NOAELs for developmental toxicity of 1310, 1280 and 1180 mg/kg body weight and day for rats, mice, and rabbits, respectively, to a concentration at the work place (2293, 1280, and 3442 mg/m3), the differences to the MAK value are considered so large, that there is no reason to fear damage to the embryo or foetus when the MAK value is observed. The classification in Pregnancy Risk Group C is therefore retained
- …
