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Gloves
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
Marie-Noëlle Crépy, Pierre Hoerner
IIR is a copolymer of isobutene (97–99.5%), and isoprene (0.5–3%) and is selected for manufacturing gloves, thanks to its low gas permeability and excellent resistance to polar solvents and corrosive chemicals. This material has good flexibility but slightly lower tensile strength than other conventional materials such as NRL, CR, or NBR. It displays poor resistance to petroleum oil and gasoline. Gloves made of IIR for industrial use are available. IIR is the material of choice for CBRN (chemical, biological, radiological, and nuclear defense) protection suits.
Chemistry of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
The other major route to citral is shown in Figure 6.39. This starts from isobutene (217) and formaldehyde (218). The ene reaction between these produces isoprenol (219). Isomerization of isoprenol over a palladium catalyst gives prenol (220) and aerial oxidation over a silver catalyst gives prenal (senecioaldehyde) (221). When heated together, these two add together to form the enol ether (222), which then undergoes a Claisen rearrangement to give the aldehyde (223). This latter molecule is perfectly set up (after rotation around the central bond) for a Cope rearrangement to give citral (71). Development chemists have always striven to produce economic processes with the highest overall yield possible thus minimizing the volume of waste and hence environmental impact. This synthesis is a very good example of the fruits of such work. The reaction scheme uses no reagents, other than oxygen, employs efficient catalysts, and produces only one by-product, water, which is environmentally benign.
Indoor Air Pollution
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
Sugie et al.41 reported three cases of sudden death due to the inhalation of portable cooking stove fuel (case 1), cigarette lighter fuel (case 2), and liquefied petroleum gas (LPG) (case 3). Specimens of blood, urine, stomach contents, brain, heart, lung, liver, kidney, and fat were collected and analyzed for propylene, propane, isobutene, and n-butane by headspace gas chromatography (GCV). n-Butane was the major substance among the volatiles found in the tissues of cases 1 and 2, and propane was the major substance in case 3. A combination of the autopsy findings and the gas analysis results revealed that the cause of death was ventricular fibrillation induced by hard muscle exercise after gas inhalation in cases 1 and 2, and that the cause of death in case 3 might be hypoxia. It is possible that the victim in case 3 was under anesthetic toxicity of accumulated isobutene which is a minor component of liquefied petroleum gas.
Development of syringes and vials for delivery of biologics: current challenges and innovative solutions
Published in Expert Opinion on Drug Delivery, 2021
Saki Yoneda, Tetsuo Torisu, Susumu Uchiyama
Current glass PFSs are lubricated with silicone oil to reduce the injection force small enough for administration. However, silicone oil may induce the formation of particles or aggregates, which is a concern [54]. Funke et al. suggest that it should not be sprayed, like in spray-on siliconized containers, but should be baked such as bake-on siliconized containers, which have the potential to decrease the migration of silicone into the drug products [81]. Nevertheless, the development of silicon oil-free PFSs is accelerating to reduce the risk of immunogenicity from silicone oil and the particles induced by silicone oil [82,83]. The strategy to achieve silicone oil-free prefilled syringes is a highly slippery plunger head with a special coating. For example, GORE & Associates, Inc (MD, USA) developed Improject Plunger, which is a silicone-free plunger coated using a PTFE-based fluoropolymer [84]. This plunger head can be used with syriQ BioPureⓇsilicone-free glass syringes (SCHOTT AG, Germany [85]). PLAJEXTM–COP syringe with chlorinated isoprene isobutene rubber plunger stopper head has also been developed by Terumo Corporation (Tokyo, Japan) [86]. PLAJEXTM successfully avoids protein adsorption and aggregation in syringes. The use of silicone oil-free syringes is expected to expand in the future. PLAJEXTM has been adopted to the primary packaging of HULIOⓇ, which is accepted as a new biosimilar product of HUMIRAⓇ in Europe [87]. The wider expansion of the use of silicone oil-free prefilled syringes can be expected in the near future.
Particle and organic vapor emissions from children’s 3-D pen and 3-D printer toys
Published in Inhalation Toxicology, 2019
Jinghai Yi, Matthew G. Duling, Lauren N. Bowers, Alycia K. Knepp, Ryan F. LeBouf, Timothy R. Nurkiewicz, Anand Ranpara, Todd Luxton, Stephen B. Martin, Dru A. Burns, Derek M. Peloquin, Eric J. Baumann, M. Abbas Virji, Aleksandr B. Stefaniak
Total VOC (TVOC) concentration in the chamber was measured using a real-time photo-ionization detector with 10.6 eV ultraviolet discharge lamp (Model 3000 ppbRAE, RAE Systems, San Jose, CA). This instrument was factory calibrated using isobutylene and span checked with isobutylene prior to use and is capable of measuring down to 1 ppb (2.3 µg/m3 isobutylene equivalent). Measurement results in ppb were converted to µg/m3 isobutylene equivalents using the molecular weight of isobutylene. Samples of VOCs were collected using whole-air 6 L Silonite®-coated canisters (Entech Instruments, Inc., Simi Valley, CA) followed by off-line analysis by gas chromatography-mass spectrometry (GC-MS, Model 7890-5975, Agilent Technologies Inc., Santa Clara, CA) to quantify 17 VOCs (NIOSH 2018) plus acetaldehyde and styrene. Two canister samples were collected during replicate printing tests, one during the background phase and the other at the mid-point of the printing phase. Collection took a period of about 1–2 min per sample.
The need for new control strategies for particulate matter in parenterals
Published in Pharmaceutical Development and Technology, 2019
Johannes Poms, Stephan Sacher, Matthias Nixdorf, Michael Dekner, Sabine Wallner-Mang, Ines Janssen, Johannes G. Khinast, Robert Schennach
Particulate matter was prepared by milling and sieving. Clean-Pak amber glass vials (Sigma Aldrich, Darmstadt, Germany) were crushed and ground in a mechanical ball mill PM 100 (Retsch, Hann, Germany). Polyethylene, polytetrafluoroethene and bromo-isobutene-isoprene rubber stoppers (all samples of production line) were ground in a CryoMill (Retsch, Hann, Germany) at an agitation frequency of 20 s−1 at liquid nitrogen temperature of −196 °C. In order to prevent particle agglomeration, small amounts of chalk were added. Stainless martensitic steel (X20Cr20) swarf was produced with a file. All impurities were separated with a sieving machine (Retsch AS200, Hann, Germany) with analytical meshes of 50, 80, 100, 160, 250, 400, 630, 800 µm generating seven different size classes in-between.