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Organization and Management of a Laser Safety Program
Published in Kenneth L. Miller, Handbook of Management of Radiation Protection Programs, 2020
Class 4 laser beams, because the minimum output power is 500 mW, can cause a fire. When a Class 4 laser beam interacts with a flammable material (liquid, gas, linen, etc.), high potential exists for spontaneous combustion. Using fire-retardant material, keeping flammable substances away from the beam, and having the appropriate fire extinguisher on-hand can make the environment safer.
Industrial Uses Of Phosphonates
Published in Richard L. Hilderbrand, The Role of Phosphonates in Living Systems, 2018
George L. Drake, Timothy A. Calamari
A fire retardant composition for polyethylene, polypropylene, polyester resins, phenolic resins, and polystyrene is produced by reacting an arylhaloalkyl phosphonate, such as cresyl- 2-bromo 3 ethylmethyl phosphonate with a chlorinated paraffin. Antimony oxide, (Sb2O3), is usually necessary in formulations of this type to produce flame retardance. This composition is effective without the use of Sb2O3 in the formulation.51–52
The environment and reproduction
Published in David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham, Textbook of Assisted Reproductive Techniques, 2017
Sharpe et al. (121) demonstrated that gestational and lactational exposure of rats to xenoestrogens resulted in reduced testicular size and sperm production (20). Dicofol, an estrogenic organochloride pesticide, was observed to induce a significant decrease in ovarian follicles and the number of estrous cycles in rabbits (21), while follicle destruction has been reported in rhesus monkeys exposed to PCBs (22). The list of mammalian studies linking subfertility to environmental toxicants is extensive, including studies demonstrating embryotoxicity for DDT, methoxychlor, and hexachlorocyclohexane (23). Most human exposure is through food, air, or, in the case of trihalomethanes (THMs), absorption through skin. Exposure to the aforementioned compounds has been well documented, but is only now being monitored more closely. There were few data about non-occupational exposure to potential toxicants until the Centers for Disease Control and Prevention (CDC) began testing in 1999 (116 compounds) and 2003 (148 compounds) (24). National Geographic published an article in 2006 about a journalist who had his blood tested for levels of environmental toxicants to see what the average American accumulates in a lifetime. The tests, which cost around $15,000, revealed 165 of 320 chemicals tested, including levels of a fire retardant used on airline seats 10 times higher than the average American, because of the many hours spent in airplanes (25). The article highlighted the fact that these chemicals are ubiquitous not only in the environment, but also in our bodies.
Lung toxicity and gene expression changes in response to whole-body inhalation exposure to cellulose nanocrystal in rats
Published in Inhalation Toxicology, 2021
Pius Joseph, Christina M. Umbright, Jenny R. Roberts, Jared L. Cumpston, Marlene S. Orandle, Walter G. McKinney, Tina M. Sager
Cellulose, the most abundant organic polymer in the biosphere, is formed by hydrogen bonding between adjacent glucose monomers and is a major component of plants, bacteria, fungi, and tunicates (Siro and Plackett 2010). Cellulose, widely considered as nontoxic, has numerous applications. It is a major component of the food cycle. Cellulose insulation, manufactured by the shredding and milling of old newspapers and the addition of fire retardant(s), is widely used as a type of thermal insulation in the construction industry (Morgan 2006). Aerosolization of respirable cellulose particles, during the manufacture and use of cellulose insulation is possible resulting in exposure of workers to the particles. This prompted the US National Toxicology Program (NTP) to conduct a study regarding the toxicity potential and health effects of cellulose. Based on the results of human studies, the NTP has concluded that inhalation exposure to the cellulose particles generated from cellulose insulation resulted in only minimal pulmonary toxicity which is attributed mainly to the chemical elements present in the fire retardant(s) added during manufacturing the cellulose insulation (Morgan 2006). Currently, the Occupational Safety and Health Administration (OSHA) regulates exposure to cellulose at a permissible exposure limit (PEL) of 15 mg/m3 (total particulate) and 5 mg/m3 (respirable particulate) (NIOSH 2019).
Preparation and characterisation of flame retardant encapsulated with functionalised silica-based shell
Published in Journal of Microencapsulation, 2018
Doan-Trang Hoang, Diane Schorr, Véronic Landry, Pierre Blanchet, Stéphanie Vanslambrouck, Christian Dagenais
Recently, it has been observed that APP encapsulated by silicon-containing compounds applied on synthetic polymers can considerably reduce its degradation caused by moisture. Furthermore, the combination of phosphorus and silicon-based compounds can improve the performance of fire retardant (Qu et al.2012, Deng et al.2014). The synergistic effect between silicon and IFR can be explained by the following mechanism: phosphorus promotes char formation, nitrogen releases gases as diluents, and silicon forms a smooth layer that protects the forming char from oxidation (Agrawal and Narula 2014). As demonstrated in various researches (Lv et al.2009, Qu et al.2012, Deng et al.2014), coating the surface of APP with an organic-inorganic hybrid polysiloxane not only allows enveloping the FR additive in a hydrophobic shell but also provides higher fire retardant properties of IFR coating.
Cold plasma assisted deposition of organosilicon coatings on stainless steel for prevention of adhesion of Salmonella enterica serovar Enteritidis
Published in Biofouling, 2021
Mayssane Hage, Simon Khelissa, Marwan Abdallah, Hikmat Akoum, Nour-Eddine Chihib, Charafeddine Jama
Bacteria within biofilms are known to be up to 1,000-fold more resistant to disinfecting agents than free-floating planktonic bacteria (Costerton et al. 1987; Stewart and Costerton 2001; Abdallah et al. 2014; Khelissa et al. 2017). Therefore, it is important to find a solution to eliminating bacterial adhesion and biofilm formation on surfaces. It has previously been reported that S. Enteritidis can adhere and form strong biofilms on materials such as stainless steel, polyurethane and polyethylene (Manijeh et al. 2008). Indeed, the adhesion capacity of S. Enteritidis is recognized as a virulence factor (Oliveira et al. 2007). In the current work, coatings were elaborated in an attempt to reduce bacterial adhesion, which is an important step in biofilm formation by Salmonella Enteritidis. The technology of surface characteristic modifications is a very promising approach to further prevent surface contamination (Feng et al. 2015). Hence, organosilicon-based coatings were deposited by a Cold Remote Nitrogen Plasma (CRNP) which is a part of the Plasma-enhanced Chemical Vapour Deposition (PE-CVD) technique. With this coating process, substrata can be covered with various types of coatings using gaseous precursors. In general, a gas monomer is fragmented, rearranged and polymerized under the influence of the plasma to generate a cross-linked coating (Dessaux et al. 1998). The deposition occurs in a downstream zone far from the discharge zone. Therefore, electrons or ions are no longer available, resulting in a higher deposition rate in comparison with the one obtained in the discharge zone. In previous work, remote plasma was used with 1,1,3,3-tetramethyldisiloxane (TMDS) to obtain plasma polymerized films showing a polysiloxane-like structure (Callebert et al. 1994; Jama et al. 1997; Quédé et al. 2002). The Cold Remote Nitrogen Plasma (CRNP) is a non-ionized zone containing reactive species like nitrogen atoms in the ground electronic state N (4S), electronically excited N2 triplet states and vibrationally excited N2 in the ground electronic state. The monomer TMDS was employed for its ability to impart a hydrophobic character to coatings (Aoyagi et al. 2012; Dimitrakellis and Gogolides 2018). These coatings are used in a wide variety of applications. Their fire-retardant properties facilitate the production of protecting polymers such as polyamide-6 (Quédé et al. 2004; Bras et al. 2005). An efficient barrier effect, using these coatings, has been used to hinder Zn2+ diffusion from rubber cups to pharmaceutical liquid (Jama et al. 1997).