bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Various Packaging Materials on Physico-Chemical Characteristics of Vacuum Fried Carrot Chips during Storage
Authors: Babu P , Rajesh G K , Shamna N P , Thasneem P Jahana , B O Madhu , G Vani
Published: November 2024

Aims: The objective of this study was to determine the effects of type of packaging materials and time of storage on the physicochemical characteristics of vacuum fried carrot chips.
Place and Duration of Study: The research work was carried out at the Dept. of Processing and Food Engineering (P&FE), Kelappaji College of Agricultural Engineering and Technology, Tavanur, Kerala during the year of 2019-20.
Methodology: The vacuum fried carrot chips were packed into three different packaging materials namely low-density polyethylene stand pouch (LDPE), laminated aluminum flexible pouch and polypropylene. All three packaging materials were tested with and without N2 gas filling. The storage studies were conducted for the vacuum fried carrot chips which was fried under optimized processing conditions: Frying Temperature-100⁰C; Frying Pressure-13 kPa; and Frying Time- 20 min. The experimental study was conducted for 4 months period and data was recorded for every 30 days interval. The packed samples were stored at the ambient temperature (25±5ºC) and relative humidity (70±10%) for storage studies. The quality attributes such as moisture content, water activity, oil content, hardness and colour values of the chips were determined during the storage studies.
Results: Based on the research study, the results shown that the oil content remained constant throughout 120 days of storage period in all packaging materials. The water activity, moisture content, hardness and colour values got increased with increase in storage time. The moisture content, water activity and hardness values were less in laminated aluminium pouches with N2 gas filling compared to polypropylene and LDPE.
Glycols – Method for the determination of diethylene glycol, ethylene glycol and propylene glycol in workplace air using gas chromatography [Air Monitoring Methods, 2018]
Authors: Giesen Y. , Friedrich C. , Breuer D. , Fauss J. , Hebisch R. , Brock T.H. , Hartwig A. ,   MAK Commission
Published: July 2018

This analytical method is a validated measurement procedure for the determination and limit value monitoring of diethylene glycol, ethylene glycol and propylene glycol in workplace air. With this method simultaneously airborne glycols in the gaseous state as well as particles are collected. Sampling is performed by drawing a defined volume of air through the sampling system GGP‐Mini consisting of a glass fibre filter and a charcoal tube connected downstream using a suitable flow‐regulated pump. The flow rate is set to 0.33 L/min with a recommended air sample volume of 40 L. The collected glycols are desorbed with a mixture of dichloromethane/methanol containing 1‐hexanol as internal standard and then analysed by means of gas chromatography using FID. The quantitative evaluation is based on calibration functions obtained by means of multiple‐point calibrations. The limit of quantification (LOQ) for the individual glycols is 0.5 mg/m
3
based on an air sample volume of 40 L.

Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working group “Air Analyses” of the Permanent Senate Commission of the Deutsche Forschungsgemeinschaft for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
2,3‐Pentanedione – Method for the determination of 2,3‐pentanedione in workplace air using high performance liquid chromatography (HPLC) [Air Monitoring Methods, 2017]
Authors: Schuh C. , Nitschke L. , Hebisch R. , Brock T.H. , Hartwig A. ,   MAK Commission
Published: July 2018

This analytical method is a validated measurement procedure for the determination of 2,3‐pentanedione in workplace air in a concentration range of a tenth up to twice the currently valid MAK value of 0.083 mg/m
3
. Sampling is performed by drawing a defined volume of air through a cartridge filled with silica gel impregnated with 2,4‐dinitrophenylhydrazine (DNPH) using a suitable flow‐regulated pump with a volumetric flow rate of 1 L/min. For sampling 1 hour or 15 min (checking the short‐term value) can be used. The formed hydrazones are desorbed with acetonitrile containing a defined amount of DNPH and analysed by means of liquid chromatography (HPLC‐UV or HPLC‐MS). Quantitative evaluation is based on a 10‐point calibration using an internal standard for analysis with HPLC‐MS and an external standard for analysis via HPLC‐UV. The limit of quantification for 2,3‐pentanedione is 0.00078 mg/m
3
based on an air sample volume of approx. 60 L or 0.0031 mg/m
3
based on an air sample volume of approx. 15 L (for short‐term value).

Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working group “Air Analyses” of the Permanent Senate Commission of the DFG for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
Sampling and analysis of substances and substance mixtures which may occur simultaneously as vapours and particles in workplace air [Air Monitoring Methods, 2018]
Authors: Breuer D. , Dragan C.G. , Hebisch R. , Bartsch R. , Giesen Y. , Krämer W. , Nitschke L. , Nitz G. , Pannwitz K.‐H. , Tschickardt M. , Brock T.H. , Hartwig A. ,   MAK Commission
Published: July 2018

Due to their physical properties semi‐volatile substances can occur as particle/vapour mixtures in workplace air. Such mixtures are formed, e.g. as a result of mechanical processes such as the processing of metals or ceramics, during dipping processes in electroplating or during spraying processes. For that reason workplace air measurements must be carried out with a suitable sampling system for the collection of particles and vapours in workplace air. This report sets out the general principles of the physical behaviour of airborne aerosols and explains the different toxic effects of both phases by inhalation. Sampling strategies for collection of particle/vapour mixtures in workplace air using generally accepted combined sampling systems are described. In addition, several approved sampling heads and sampling systems such as GSP, GSP‐Mini, GGP/GGP‐U are presented. Influences on the measurement results such as temperature, humidity, sampling, transport and storage are discussed and the calculation of the expanded uncertainty when measuring these special kinds of substances is explained.

Joint Publication of the Analytical Subcommittee of the Chemistry Board of Experts of the Expert Committee Raw Materials and Chemical Industry of the German Social Accident Insurance and the working Group “Air Analyses” of the Permanent Senate Commission of the DFG for the Investigation of Health Hazards of Chemical Compounds in the Work Area.
Iodine and inorganic iodides [BAT Value Documentation, 2016]
Authors: Nasterlack M. , Drexler H. , Hartwig A. ,   MAK Commission
Published: July 2018

In 2015 the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated iodine [CAS No.
7553‐56‐2
] and inorganic iodides. Available publications are described in detail.

There is no reproducible quantitative relation between iodine exposure, absorption and resulting body burden. The association between iodine absorption and the incidence of thyroid dysfunction seems to be U‐shaped. Therefore, no sharp boundary can be drawn between iodine oversupply and iodine deficiency relating to individual health. No harmless range could be indicated, so a BAT value (biological tolerance value) for iodine and inorganic iodides could not be derived.

There are major regional differences due to different geological deposits of iodine, different concentrations of iodine in drinking water, iodine‐containing aerosols and nutritional habits. Furthermore, there is a high variability in the urinary analysis. Therefore, a BAR (“Biologischer Arbeitsstoff‐Referenzwert”) for iodine and inorganic iodides could not be derived.
Benzol, Toluol, o‐Xylol, m‐Xylol, p‐Xylol, Ethylbenzol, Styrol und iso‐Propylbenzol (Cumol) – Bestimmung von Aromaten in Urin mittels dynamischer Headspace‐GC‐MS [Biomonitoring Methods in German language, 2018]
Authors: Van Pul J. , Roßbach B. , Göen T. , Hartwig A. ,   MAK Commission
Published: July 2018

The working group „Analyses in Biological Materials“ of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the presented biomonitoring method.

The analytical method described hereinafter permits the simultaneous determination of the following unmetabolised aromatic compounds in urine: benzene, toluene, o‐xylene, m‐xylene, p‐xylene, ethylbenzene, styrene and isopropylbenzene (cumene). Prior to the determination of the analytes by GC‐MS, the analytes are extracted and enriched using ITEX (In Tube Extraction) or SPDE (Solid Phase Dynamic Extraction). To this end, the urine samples are incubated at 50 °C, the analytes extracted from the gas phase and then the enriched analytes are transferred to the gas chromatograph and analysed using mass spectrometry. Calibration standards are prepared in water and processed in the same way as the samples to be analysed. Deuterated benzene is used as internal standard.

The method was extensively validated and the reliability data were confirmed by an independent laboratory, which has established and cross‐checked the whole procedure.
Benzene, toluene, o‐xylene, m‐xylene, p‐xylene, ethylbenzene, styrene, isopropylbenzene (cumene) – Determination of aromatic compounds in urine by dynamic headspace GC‐MS [Biomonitoring Methods, 2018]
Authors: Van Pul J. , Roßbach B. , Göen T. , Hartwig A. ,   MAK Commission
Published: July 2018

The working group „Analyses in Biological Materials“ of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the presented biomonitoring method.

The analytical method described hereinafter permits the simultaneous determination of the following unmetabolised aromatic compounds in urine: benzene, toluene, o‐xylene, m‐xylene, p‐xylene, ethylbenzene, styrene and isopropylbenzene (cumene). Prior to the determination of the analytes by GC‐MS, the analytes are extracted and enriched using ITEX (In Tube Extraction) or SPDE (Solid Phase Dynamic Extraction). To this end, the urine samples are incubated at 50 °C, the analytes extracted from the gas phase and then the enriched analytes are transferred to the gas chromatograph and analysed using mass spectrometry. Calibration standards are prepared in water and processed in the same way as the samples to be analysed. Deuterated benzene is used as internal standard.

The method was extensively validated and the reliability data were confirmed by an independent laboratory, which has established and cross‐checked the whole procedure.
Komponenten von Kühlschmierstoffen, Hydraulikflüssigkeiten und anderen Schmierstoffen [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has been evaluating components of metal‐working fluids since 1982. A list of these compounds has been published and updated regularly in cooperation with German manufacturers of lubricants. As significant amounts of hydraulic fluids as well as other lubricants can leak into metal‐working fluids during their application, these components are also listed. The list contains about 360 components or component groups; however, it is not complete because there is no obligation to declare all components. This is especially true for metal‐working fluids. CAS numbers and structural formulae as well as the use concentration are given, if known. Compounds which are no longer allowed to be used in metal‐working fluids are mentioned in a “historical” list with the reason for their discontinuation. The reader is advised to check whether an evaluation of the toxicity by the Commission exists for the component of interest.
Faserstäube, anorganisch [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has reevaluated the general aspects of the toxicity of inorganic fibrous dusts. As a first step a documentation on the effects caused by inhalation of inorganic fibrous dusts and the mode of action for their toxicity was set up. For the elucidation of the mechanism of the toxicity and carcinogenicity of fibers, data derived from studies with asbestos fibers were also considered, in order to obtain some knowledge with regard to the biological effects of the other inorganic fibrous dusts. The formation of tumors in the lungs and on serous membranes is mainly the result of inflammatory processes. Chronic inflammation and cell proliferation are caused by the impairment of fiber clearance, whereby inflammation‐promoting cytokines, growth factors, reactive oxygen (ROS) and nitrogen species (RNS) and chlorine radicals are released from the macrophages, inflammatory cells, alveolar cells and mesothelial cells. The generation of these radicals leads to genotoxic effects. In addition intracellular formation of ROS and RNS can be caused by the fibers themselves, as a result of their own surface reactivity. Fibers can stimulate cell receptors and inflammasomes.

Each fiber dust group will be evaluated individually and, depending on the data available, may be classified in one of the categories for carcinogens. The Commission has already begun this procedure.
Benzyl alcohol [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated benzyl alcohol [100‐51‐6] to derive a maximum concentration at the workplace (MAK value), considering all toxicological endpoints. Available publications and study reports are described in detail.

Benzyl alcohol is irritating to the eyes and the airways. In a 4‐week inhalation study in rats, microscopic lesions in the airways, especially in the lung, occurred at 1072 mg/m3. The NAEC is estimated to be 300 mg/m3, a concentration at which benzyl alcohol can occur as vapour, corresponding to 67 ml/m3. A MAK value of 5 ml/m3has been derived. As local effects are critical, benzyl alcohol is classified in Peak Limitation Category I with an excursion factor of 2.

In developmental toxicity studies with benzyl alcohol in mice, foetotoxic effects occurred at 750 mg/kg body weight and day in the presence of marked maternal toxicity. The NOAEL was 550 mg/kg body weight and day; however, teratogenicity was not examined. Benzoic acid is the main metabolite of benzyl alcohol. Considering the developmental toxicity studies with sodium benzoate, the differences between the NOAEL for rats, mice, rabbits and hamsters scaled to an inhalation concentration at the workplace and the MAK value are considered so large that damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, benzyl alcohol is classified in Pregnancy Risk Group C.

Benzyl alcohol is not regarded to be genotoxic or carcinogenic. Sensitization is not expected as benzyl alcohol was not a contact sensitizer in a local lymph node assay and there were no conclusive positive clinical findings of sensitizing effects on the skin. Skin contact is expected to contribute significantly to the systemic toxicity. Therefore, benzyl alcohol is designated with an “H”.

Completed: October 08, 2015
Cyclohexylamine [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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) for cyclohexylamine.

A 4‐hour inhalation study with volunteers showed clear irritation at 10 ml/m
3
, whereas a time‐weighted average concentration of 2 ml/m
3
with peaks of up to 4 ml/m
3
was without impact on sensory irritation parameters and neurobehavioral measurements. The MAK value of 2 ml/m
3
and classification in Peak Limitation Category I has been retained. No irritation was observed up to 4 ml/m
3
; therefore, the excursion factor 2 has been retained as well. As cyclohexylamine is a strong base and 10 ml/m
3
is clearly irritating, a momentary value of 5 ml/m
3
is set.

Completed: April 20, 2016
Azodicarbonamide [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated azodicarbonamide [123‐77‐3] to derive a maximum concentration at the workplace (MAK value), considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. The critical effect is the occurrence of reactions in the airways in exposed workers. In the view of the Commission, the present inhalation studies in animals are not appropriate for the derivation of a MAK value as human airways are probably more sensitive than rodent airways. The workplace investigations show no clear correlation of exposure and frequency of respiratory symptoms. Nevertheless, from the NOAEC of 36 µg/m3for lung function measurements in a small group of injection‐molding workers in the plastics industry, a MAK value of 20 µg/m3 I is established. Due to the incomplete information on the relevant exposure scenario and the uncertainty regarding first occurrence of workplace related symptoms, this value should be considered as preliminary. As local effects are critical, azodicarbonamide is assigned to Peak Limitation Category I and the default excursion factor of 1 is designated. Since developmental toxicity studies are not available, Pregnancy Risk Group D is assigned. There are no carcinogenicity studies and azodicarbonamide is not regarded as germ cell mutagen. Skin contact is not expected to contribute significantly to systemic toxicity. The metabolism of azodicarbonamide and its reactivity do not point to stable protein binding in vivo and therefore, skin or respiratory sensitization is unlikely. Clear‐cut clinical findings or positive results from animal studies on skin sensitization are not available, but the negative results in experimental animals are difficult to evaluate due to the low solubility of the compound. Although azodicarbonamide affects the respiratory tract in several case reports with positive bronchial provocation tests, sensitization by a known mechanism is not adequately verified. Additionally, it appears questionable whether a mono‐causal relationship of respiratory symptoms and azodicarbonamide exposure can really be assumed. In conclusion, a sensitizing effect of azodicarbonamide is not sufficiently proven.

Completed: March 22, 2017
Adipic acid [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated adipic acid [
124‐04‐9
] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints.

The critical effect is moderate local irritation as shown with the Draize test in the rabbit eye. Available inhalation studies are limited and not suitable to derive a MAK value. Systemic toxicity only occurs at high doses. In a limited oral 2‐year study the body weight of rats was reduced at 2250 mg/kg body weight/day. The resulting systemic NOAEL is 750 mg/kg body weight/day.

After comparing adipic acid with other solid acids, a MAK value of 2 mg adipic acid/m
3
I has been set in analogy to phosphoric acid, which is considered to be the worst‐case.

As the critical effect is local, adipic acid is assigned to Peak Limitation Category I. In analogy to phosphoric acid, a default excursion factor of 2 is set.

Damage to the embryo or foetus is unlikely when the MAK value is observed; thus, the substance is classified in Pregnancy Risk Group C.

Adipic acid is not genotoxic and not carcinogenic. No contact sensitizing effects have been observed. Skin contact is not expected to contribute significantly to systemic toxicity.

Completed: February 24, 2016
N,N‐Dimethylacetamid [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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) and the Pregnancy Risk Group of N,N‐dimethylacetamide [
127‐19‐5
].

N,N‐Dimethylacetamide causes focal cystic degenerations, peliosis, hemosiderin/lipofuscin accumulation and apoptosis in the liver of rats and male mice after chronic whole body inhalation at 100 ml/m
3
. The NOAEC in both species is 25 ml/m
3
. Elastane fibre workers with exposure to N,N‐dimethylacetamide show hepatocellular injury. The data at the workplace is not adequate to derive a MAK value. The former MAK value of 10 ml/m
3
was derived from the NOAEC of 25 ml/m
3
in rats and mice. The MAK value is now lowered to 5 ml/m
3
which takes into account the increased respiratory volume at the workplace because the blood:air partition coefficient of N,N‐dimethylacetamide is > 5 (see List of MAK‐ and BAT Values chapters I b and I c). Since a systemic effect is critical, Peak Limitation Category II is retained. The default excursion factor of 2 is retained as well, as the mechanism of action and the half‐life in blood are not known.

In rats and rabbits, N,N‐dimethylacetamide induces via inhalation at 450 or 570 ml/m
3
, respectively, and above, specific teratogenic effects, cardiovascular and skeletal malformations. The NOAEC for teratogenicity in rats and rabbits are 300 or 200 ml/m
3
, respectively. The lowest NOAEC for developmental toxicity in rats and rabbits are 100 and 57 ml/m
3
, respectively. Considering the increased respiratory volume at the workplace, the NOAEC for rabbits is only six times the MAK value. However, taking into account that the NOAEC could be higher than 57 ml/m
3
and the observed effects, reduced fetal body weight and increased incidence of skeletal variations, are considered marginal, the difference to the MAK value is sufficient. Therefore, damage to the embryo or foetus is unlikely when the MAK value is observed and N,N‐dimethylacetamide remains assigned to Pregnancy Risk Group C. Skin contact should be avoided as N,N‐dimethylacetamide is designated with an “H”.
4‐
tert
‐Octylphenol [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated the developmental toxicity of 4‐tert‐octylphenol. In 2015, the maximum concentration at the workplace (MAK value) for 4‐tert‐octylphenol was set at 0.5 ml /m
3
(4.3 mg/m
3
).

In a screening study in rats with gavage administration, litter size and body weight of the progeny at postnatal day 4 was reduced at 500 mg/kg body weight and day, accompanied by maternal toxicity. A NOAEL for foetotoxicity of 250 mg/kg body weight and day was derived, corresponding to a concentration of 28.5 ml/m
3
at the workplace. In a 2‐generation feeding study in rats, foetotoxicity was not observed until postnatal day 13. At 111–369 mg/kg body weight and day, vaginal opening or preputial separation of the F2 progeny was delayed. A NOAEL of 10.9–32.6 mg/kg body weight and day was derived for postnatal developmental toxicity in rats, corresponding to 1.2–3.7 ml/m
3
. Because adequate studies of prenatal developmental toxicity over the complete period of organogenesis are lacking, data are not sufficient for classification and 4‐tert‐octylphenol is assigned to Pregnancy Risk Group D.

Completed: October 7, 2015
2‐Aminoethanol [MAK Value Documentation, 2016]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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 2‐aminoethanol [141‐43‐5], considering the endpoints respiratory tract irritation, developmental toxicity, and skin absorption. Available unpublished study reports are described in detail.

Critical effect of 2‐aminoethanol is the local respiratory tract irritation. New 5‐day and 28‐day‐guideline‐studies with rats show time‐ and dose‐dependent effects in larynx (squamous metaplasia, inflammation, necrosis), trachea (squamous metaplasia, inflammation), and lung (hyperplasia of mucous and goblet cells). The NOAEC is 10 mg/m
3
(3,95 ml/m
3
). 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 0.22  ml/m
3
for the work place air can be calculated from this study, resulting in a MAK value of 0.2 ml/m
3
. Since the critical effect is irritation, Peak Limitation Category I is retained with an excursion factor of 1 as the substance is corrosive.

After scaling the oral NOAEL for developmental toxicity of 75, 225, and 500 mg/kg body weight and day for rabbits (dermal) and rats (dermal, oral), respectively, to an inhalation concentration at the work place, the differences to the MAK value, are considered sufficient, and damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, classification in Pregnancy Risk Group C is confirmed.

Absorption via skin does not contribute significantly to the systemic toxicity of 2‐aminoethanol.

Completed: March 23, 2015
Lauric acid [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated lauric acid [143‐07‐7], considering all toxicity endpoints.

In an oral 18‐week study no substance‐related effects were observed in rats up to 9000 mg/kg body weight and day. As lauric acid is an organic acid, the respiratory tract might be a target organ; however, inhalation studies are not available. A maximum concentration at the workplace (MAK value) was derived by read across to other solid acids. Lauric acid is irritating to the rabbit eye but less so than succinic and adipic acid. Also the acidity of saturated solutions of lauric acid is less than that of succinic and adipic acid. For the latter acids, a MAK value of 2 mg/m3 for the inhalable fraction was set like that for phosphoric acid. Phosphoric acid is a stronger acid that is corrosive to the eyes of rabbits. Therefore, in analogy to phosphoric acid as a worst‐case, a MAK value of 2 mg/m3 for the inhalable fraction is set for lauric acid.

As the MAK value has been derived in analogy to phosphoric acid, lauric acid is also classified in Peak Limitation Category I with an excursion factor of 2.

Lauric acid does not have genotoxic potential. There are no carcinogenicity studies available with lauric acid. Results of a dermal initiation‐promotion study with lauric acid alone were negative; promoting activity was seen only after application of an initiator. Lauric acid is no longer classified as carcinogenic to humans, based on the Commission's evaluation of this type of study.

No significant contribution to systemic toxicity was demonstrated in calculations of dermal absorption. Limited data in animals do not indicate a sensitizing potential for lauric acid.

Developmental toxicity studies are lacking; therefore, lauric acid is assigned to Pregnancy Risk Group D.

Completed: February 24, 2016
Dipropylene glycol [MAK Value Documentation, 2016]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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) for dipropylene glycol has been set at 100 mg/m
3
for the inhalable fraction, considering the endpoints respiratory tract irritation and systemic toxicity as well as absorption through the skin. A 2‐year drinking water study with rats shows a NOAEL for focal inflammation of the liver in males of 115 mg/kg body weight and day and a NOAEL for olfactory epithelium degeneration in males and females of 470 and 530 mg/kg body weight and day, respectively. This raises the question, whether the olfactory epithelium could also be a local target tissue after inhalation. Inhalation studies with dipropylene glycol are not available. The substance shows very slight irritation of skin and eyes, if any. Thus, there are no indications of a potential local irritative effect to the upper airways. Therefore, the MAK value of 100 mg/m
3
derived from systemic effects is validated. As systemic effects are critical, the assignment to Peak Limitation Category II and the excursion factor of 2 are retained. A recent in‐vitro study with human skin shows that skin contact does not contribute significantly to systemic toxicity and the former designation with an “H” notation is withdrawn.

Completed: March 23, 2015
2‐(Propyloxy)ethanol (2‐Propoxyethanol) [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated 2‐(propyloxy)ethanol [
2807‐30‐9
] considering all toxicological endpoints.

2‐(Propyloxy)ethanol is a haemolytic and irritant glycol ether, similar to the homologous 2‐butoxyethanol. The haemolytic activity for both compounds is mediated by the corresponding alkoxy acid and is lower in human erythrocytes than in rat erythrocytes in vitro. The critical effect is the irritation seen in subchronic studies in rats at the lowest concentration tested of 100 ml/m
3
. A NOAEC was not obtained. For 2‐butoxyethanol the NOAEC for nasal effects in rats was 31 ml/m
3
. Therefore, by analogy with the better investigated 2‐butoxyethanol, the maximum concentration at the workplace (MAK value) of 2‐(propyloxy)ethanol is lowered to 10 ml/m
3
. This limit also protects from systemic toxicity. The assignment to Peak Limitation Category I with an excursion factor of 2 is retained.

A prenatal toxicity study in rats was re‐evaluated by the Commission and the NOAEC for developmental toxicity of 400 ml/m
3
was confirmed. In rabbits, the NOAEC for developmental toxicity is 500 ml/m
3
. Even after considering the increased respiratory volume at the workplace the differences of both NOAECs to the MAK value are sufficient. Therefore, damage to the embryo or foetus is unlikely when the MAK value is observed and 2‐(propyloxy)ethanol remains assigned to Pregnancy Risk Group C.

2‐(Propyloxy)ethanol is not genotoxic in vitro. In vivo studies as well as carcinogenicity studies are not available.

Percutaneous absorption can contribute significantly to systemic toxicity and 2‐(propyloxy)ethanol remains designated with an “H” notation. Results in animal studies do not point to a sensitization potential.
Trimethylpentane (all isomers) [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated trimethylpentane (all isomers), considering all toxicity endpoints. Available unpublished study reports and publications are described in detail.

The re‐examination determined that it is difficult to draw final conclusions from a carcinogenicity study of a mixture of 542 hydrocarbons and from mechanistical studies with some of their single components. Thus, the assignment to Carcinogen Category 3 A has been withdrawn. The critical effect is the acute effect on the central nervous system in rats. The NOAEC after 60 min inhalation is 500 ml 2,2,4‐trimethylpentane/m
3
. Experimental data from structurally analogous n‐alkanes and iso‐alkanes lead to the assumption that the concentration of 2,2,4‐trimethylpentane in the brain after 8 hours will be about twice as high as after one hour. The short half‐life in the brain, estimated to be about one hour, does not predict an accumulation during the work week. The same assumptions are made for the other trimethylpentane isomers. Thus, taking into consideration uncertainties in the extrapolation of animal to human data, a MAK value of 100 ml/m
3
(470 mg/m
3
) is set for all trimethylpentane isomers. As the critical effect is systemic, trimethylpentane isomers are assigned to Peak Limitation Category II. The excursion factor of 2 is set as the estimated half‐life in the brain is one hour or even less. Prenatal developmental toxicity studies with trimethylpentane isomers are not available. For structurally analogous C8‐isoalkanes the NOAEC for developmental toxicity in rats is more than 1200 ml/m
3
. Acute neurotoxicity is critical, but the consequences of acute neurotoxic effects on in‐utero development of the nervous system are not knownand studies on developmental neurotoxicity of C8‐alkanes are not available. Thus, trimethylpentane isomers are classified in Pregnancy Risk Group D. There are no clinical data and no data in animals concerning the sensitizing potential of trimethylpentane isomers. In analogy to n‐heptane, skin contact is not expected to contribute significantly to systemic toxicity.

Completed: June 24, 2016
Di‐tert‐dodecylpentasulfid / Di‐tert‐dodecylpolysulfid [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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), the Pregnancy Risk Group and the absorption through the skin of di(tert‐dodecyl)polysulfide [
68583‐56‐2
;
68425‐15‐0
] (di(tert‐dodecyl)pentasulfide [
31565‐23‐8
]).

The systemic toxicity is low and the substance is at most minimally irritating to skin and eye. Acidophilic globuli are present in the kidney of male rats in an oral 28‐day study at 50 mg/kg body weight and day, resulting from an α2u‐globulin mediated kidney toxicity which, however, is not relevant for humans. Based on this the NOAEL of 1000 mg/kg body weight and day, the MAK value would be 200 mg/m
3
. However, the substance is a poorly water‐soluble liquid and an accumulation in the lung is expected. Most of the molecule consists of hydrocarbon chains resulting in characteristics similar to severely refined mineral oil, for which a MAK value of 5 mg/m
3
had been set as the respirable fraction (R) based on inhalation studies. Therefore, the MAK‐value for di(tert‐dodecyl)polysulfide is also set at 5 mg/m
3
R. Peak Limitation is designated as well by analogy with severely refined mineral oil with Category II and excursion factor of 4.

New data on developmental toxicity are not available. As the MAK value is lowered, Pregnancy Risk Group C is retained. Skin contact is not expected to contribute significantly to systemic toxicity.
2‐Propanol [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The 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) and the Pregnancy Risk Group of 2‐propanol [67‐63‐0].

In carcinogenicity studies no tumours were observed in rats and mice up to 5000 ml/m3. From the LOAEC in rats and mice of 2500 ml/m3where narcotic effects were observed, a MAK value of 200 ml/m3is derived also considering the increased respiratory volume at the workplace because the blood:air partition coefficient of 2‐propanol is > 5 (see List of MAK‐ and BAT Values, chapters I b and I c). Therefore, the MAK value of 200 ml/m3is confirmed. At this concentration, no irritation is expected in humans based on the limited data in humans and animals.

Since a systemic effect is critical, Peak Limitation Category II is retained for 2‐propanol. Due to the half‐life of up to 2 hours in rats, the excursion factor of 2 is confirmed.

In developmental toxicity studies, 2‐propanol does not result in teratogenicity but in fetotoxicity at maternally toxic doses in rats and rabbits. According to a PBPK model and considering the increased respiratory volume at the workplace, the NOAEL of 600 mg/kg body weight in rats is scaled to a concentration of 1000 ml/m3. There is no PBPK model for rabbits but due to the similar NOAEL for developmental toxicity in rabbits the same concentration is supposed. Because fetotoxicity was only observed at maternally toxic doses, the difference of the NOAEC for fetotoxicity and the MAK value is sufficient so that 2‐propanol remains assigned to Pregnancy Risk Group C.
Benzylbutylphthalat [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: July 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated benzyl butyl phthalate [85‐68‐7] to derive a maximum concentration at the workplace (MAK value), considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. Critical effect is the toxicity to kidneys and liver. In higher doses benzyl butyl phthalate acts adversely to male reproductive organs, fertility and fetal development. The NOAEC of 218 mg/m3derived from a 13‐week inhalation study in rats is used to set a MAK value of 20 mg/m3for the respirable fraction (R), the MAK value is supported by the long‐term feeding studies in rats and mice.

Since a systemic effect is critical, Peak Limitation Category II is assigned. The default excursion factor of 2 is set as no half‐life in blood is known.

In prenatal toxicity studies in rats at 450 mg/kg body weight and day and above an increased number of resorptions and at 750 mg/kg body weight and day increased mortality and teratogenicity occurred, with a NOAEL of 350 mg/kg body weight and day. From a 2‐generation study in rats a NOAEL for fetotoxicity of 100 mg/kg body weight and day was derived. In a prenatal study in mice the LOAEL for increased resorptions and malformations was 910 mg/kg body weight and day with a NOAEL of 182 mg/kg body weight and day. The NOAELs can be scaled to concentrations of 613 mg/m3(rat, prenatal), 182 mg/m3(mice, prenatal) and 245 mg/m3(rat, pre‐ and postnatal), respectively, at the workplace. Thus, damage to the embryo or foetus is unlikely when the MAK value is observed, and benzyl butyl phthalate is classified in Pregnancy Risk Group C.

Available in vitro and in vivo data predominantly show no genotoxic effects. A contribution of cytotoxic effects for some positive test results cannot be excluded. A dominant lethal test with subcutaneous administration to rats was negative. Therefore, the substance is not regarded as a germ cell mutagen.

No increased tumour incidence was observed in chronic feeding studies in mice. In F344 rats at high doses an increased incidence of mononuclear cell leukemia is observed, which was within the range of the historical control. Furthermore in F344 rats incidences of adenomas (pancreas tumours, adrenal phaeochromocytomas, urinary bladder tumours), but not of carcinomas are increased. The adenoma incidences were mainly within the range of historical controls. A carcinogenic effect in humans, therefore, is unlikely.

Skin contact is not expected to contribute significantly to systemic toxicity.

Data in humans and limited data in animals do not show a skin sensitizing potential.
DVH Analytics: A DVH database for clinicians and researchers
Authors: Cutright Dan , Gopalakrishnan Mahesh , Roy Arkajyoti , Panchal Aditya , Mittal Bharat B.
Published: July 2018

In this study, we build a vendor‐agnostic software application capable of importing and analyzing non‐image‐based DICOM files for various radiation treatment modalities (i.e., DICOM RT Dose, RT Structure, and RT Plan files). Dose‐volume histogram (DVH) and planning data are imported into a SQL database, and methods are provided to manage, edit, view, and download data. Furthermore, the software provides various analytical tools for plan evaluations, plan comparisons, benchmarking, and plan outcome predictions. DVH Analytics is developed using Python, including libraries such as pydicom, dicompyler, psycopg2, SciPy, Statsmodels, and Bokeh for parsing DICOM files, computing DVHs, communicating with a PostgreSQL database, performing statistical analyses, and creating a web‐based user interface. This software is open‐source and compatible with Windows, Mac OS, and Linux. For proof‐of‐concept, a database with over 3,000 DVHs from a single physician's head & neck practice was built. From these data, differences in means, correlations, and temporal trends in dose to multiple organs‐at‐risk (OARs) were observed. Furthermore, an example of the predictive regression tool is reported, where a model was constructed to predict maximum dose to brainstem based on minimum distance from planning target volume (PTV) and treatment beam source‐to‐skin distance (SSD). With DVH Analytics, we have developed a free, open‐source software program to parse, organize, and analyze non‐image‐based DICOM data for use in a radiation oncology setting. Furthermore, this software can be used to generate statistical models for the purposes of quality control or outcome predictions and correlations.
Fluorescent Organic Glass with Unique Optical and Mechanical Properties
Authors: Ku Kahoe , Joung Joonyoung F. , Park Heeyeon , Kim Myeong‐Geun , Park Sungnam , Kim Woong
Published: July 2018

Conventional organic glasses such as molecular and polymeric glasses either lack processability or have ill‐defined properties. Here, a novel organic glass is reported having well‐defined fluorescent properties and high compatibility with various fabrication processes. The fluorescent organic glass (FOG) is synthesized by simply heating benzyl alcohol with a small amount of aqueous sulfuric acid. Owing to its outstanding optical properties, FOG is placed beyond the domain of conventional organic glasses in the Abbe diagram. Moreover, excellent rheological properties render it amenable to molding, blowing, and nanopatterning processes. Finally, based on extensive characterization, it is proposed that a FOG is composed of a 1,2,3,4‐tetraphenyl‐1,3‐butadiene core and poly(phenylene methylene) branches, which are responsible for molecular fluorescence and polymeric processability, respectively. The demonstration may contribute significantly to the development of organic glasses with unprecedented properties for various applications.
In Vivo Imaging of MMP‐13 Activity Using a Specific Polymer‐FRET Peptide Conjugate Detects Early Osteoarthritis and Inhibitor Efficacy
Authors: Duro‐Castano Aroa , Lim Ngee Han , Tranchant Isabelle , Amoura Mehdi , Beau Fabrice , Wieland Heike , Kingler Otmar , Herrmann Matthias , Nazaré Marc , Plettenburg Oliver , Dive Vincent , Vicent María J. , Nagase Hideaki
Published: July 2018

Imaging early molecular changes in osteoarthritic (OA) joints is instrumental for the development of disease‐modifying drugs. To this end, a fluorescent resonance energy transfer‐based peptide probe that is cleavable by matrix metalloproteinase 13 (MMP‐13) has been developed. This protease degrades type II collagen, a major matrix component of cartilage. The probe exhibits high catalytic efficiency (kcat/KM = 6.5 × 105m−1 s−1) and high selectivity for MMP‐13 over a set of nine MMPs. To achieve optimal in vivo pharmacokinetics and tissue penetration, the probe has been further conjugated to a linear l‐polyglutamate chain of 30 kDa. The conjugate detects early biochemical events that occur in a surgically induced murine model of OA before major histological changes. The nanometric probe is suitable for the monitoring of in vivo efficacy of an orally bioavailable MMP‐13 inhibitor, which effectively blocks cartilage degradation during the development of OA. This new polymer‐probe can therefore be a useful tool in detecting early OA, disease progression, and in developing MMP‐13‐based disease‐modifying drugs for OA.
VOx@MoO3 Nanorod Composite for High‐Performance Supercapacitors
Authors: Wang Si‐Qi , Cai Xiang , Song Yu , Sun Xiaoqi , Liu Xiao‐Xia
Published: July 2018

Vanadium oxide is a promising pseudocapacitive electrode, but their capacitance, especially at high current densities, requires improvement for practical applications. Herein, a VOx@MoO3 composite electrode is constructed through a facile electrochemical method. Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy demonstrate a modification on the chemical environment and electronic structure of VOx upon the effective interaction with the thin layer of MoO3. A careful investigation of the electrochemical impedance spectroscopy data reveals much enhanced power capability of the composite electrode. More charge storage sites will also be created at/near the heterogeneous interface. Due to those synergistic effects, the VOx@MoO3 electrode shows excellent electrochemical performance. It provides a high capacitance of 1980 mF cm−2 at 2 mA cm−2. Even at the high current density of 100 mA cm−2, it still achieves 1166 mF cm−2 capacitance, which doubles the sum of single electrodes. The MoO3 layer also helps to prevent VOx structure deformation, and 94% capacitance retention over 10 000 cycles is obtained for the composite electrode. This work demonstrates an effective strategy to induce interactions between heterogeneous components and enhance the electrochemical performance, which can also be applied to other pseudocapacitive electrode candidates.
Exponential Lag Synchronization of Memristive Neural Networks with Reaction Diffusion Terms via Neural Activation Function Control and Fuzzy Model
Authors: Liu Yicheng , Liao Xiaofeng , Li Chuandong
Published: July 2018

This paper is concerned with the problem of exponential lag synchronization of memristive neural networks with reaction diffusion terms via neural activation function control and fuzzy model. An memristor‐based circuit which exhibits the feature of pinched hysteresis is introduced and further, the memristive neural networks with reaction diffusion terms and such system containing fuzzy model are described at length, respectively. By utilizing the Lyapunov functional method and the neural activation function controller depending on the output of the system in the case of packed circuits, some concise conditions are acquired to guarantee the slave systems exponential lag synchronized with the master systems. Finally, several simulated examples are also presented to demonstrate the correctness of the theoretical results.