Membranes safety

From these considerations it can be concluded that, at the actual membrane state-of-the-art, SMR is the leading architecture for membrane safety, for the possibility of increasing reaction temperature up to value equal to 650 °C for natural gas steam reforming and for its maintenance easiness. Surely, a future improvement of membrane performance, mainly for stability, would promote the applications of IMRs. 

The system is intended to prevent inadmissible increase of pressure in the primary circuit if all subsystems for residual heat removal fail following the reactor shutdown. Primary circuit emergency pressure decrease is provided by two systems. The first system consists of two sets of safety devices (SD) and of a 1.6 m cooled dump tank. When the primary circuit pressure reaches 19.6 MPa the SD actuates automatically and discharges a portion of coolant into the dump tank. The system can be used repeatedly following dump tank drainage. Automatic membrane safety devices (ASD) are provided to protect the primary circuit against damage in case... 

These are typically built on a polyester base membrane (PETP, 35 pm, copper-laminated) with a polyester spacer membrane, safety chamber and front membrane. The snap disc being gold plated stainless steel. Other designs use electrical contacts made from silver, silver on carbon or carbon only. Keypads may also be made from conductive silicone rubber. Conventional computer keyboards made from ABS, polyester or other polymers, may be covered by a polymer overlay to protect it against dirt, dust, water or other substance present in a hostile environment. Polyester and PVC overlays are used in a wide variety of applications with computer and instrumentation equipment in dental and medical healthcare and other areas. Typical casing materials include PC and polychloroprene. 

E.I. du Pont de Nemours and Co., Nafion perfluorinated membranes—safety in handling and use. Bulletin E-38524, Polymer Products Department Wilmington, DE, 1983. 

Health and Safety Factors. Like other low molecular weight ketones, MIBK is an anesthetic chemical with no highly cumulative toxicological effects. Inhalation of vapors can irritate mucous membranes. 

Health and Safety Factors, Toxicology. Phosphoms trichloride severely bums skin, eyes, and mucous membranes. Contaminated clothing must be removed immediately. Vapors from minor inhalation exposure can cause delayed onset of severe respiratory symptoms after 2—24 h, depending on the degree of exposure. Delayed, massive, or acute pulmonary edema and death can develop as consequences of inhalation exposure. 

Health and Safety Factors. Both pyromellitic acid and its dianhydride irritate skin, eyes, and mucous membranes, and they cause skin sensitization (156). When it comes in contact with moist tissue the dianhydride converts to the acid. Direct contact with should be avoided and protective clothing should be worn in areas where it is used. The LD q for intergastric administration in rats is 2.2—2.6 g/kg (157). In 6-mo experiments, the maximum nontoxic dose was 0.07 mg/kg/d, and it affected the fiver, kidney, and reproductive tract. Precautions against fire and dust explosions as explained in the terephthafic acid section should be foUowed. 

Potassium forms corrosive potassium hydroxide and Hberates explosive hydrogen gas upon reaction with water and moisture. Airborne potassium dusts or potassium combustion products attack mucous membranes and skin causing bums and skin cauterization. Inhalation and skin contact must be avoided. Safety goggles, full face shields, respirators, leather gloves, fire-resistant clothing, and a leather apron are considered minimum safety equipment. 

Exposure to tantalum metal dust may cause eye injury and mucous-membrane irritation. The threshold limit value (TLV) in air is 5 mg/m, LD q is <400 mg/kg and the Occupational Safety and Health Administration (OSHA) time weighted average (TWA) exposure limit is 5 mg/m (47). The immediate dangerous to life or health (IDLH) concentration is 2500 mg/m (48). Whereas some skin injuries from tantalum have been reported, systemic industrial poisoning is apparently unknown (47). 

Health and Safety. Eree phenols may be present in phenoHc novolacs and resoles. Phenol [108-95-2] is poisonous and caustic, irritating the skin and mucous membranes. Eormaldehyde and ammonia [7764-41-7] are often emitted during the cure of novolacs and must be properly vented. Eormaldehyde is Hsted as a human carcinogen worker exposure and emissions are controUed by OSHA and the EPA. 

Disposables For smaller MF applications, short membrane life is a traditional characteristic. In these apphcations, costs are dominated by the disposables, and an important characteristic of equipment design is the ease, economy, and safety of membrane replacement. 

Hygiene and Regulation Almost unique to MF is the influence of regulatoiy concerns in selec tion and implementation of a suitable microfilter. Since MF is heavily involved with industries regulated by the Food and Drug Administration, concerns about process stabihty, consistency of manufacture, virus reduc tion, pathogen control, and material safety loom far larger than is usually found in other membrane separations. 

The monomers, eatalysts or hardeners, or plastieizers ean inelude ehemieals with the potential to irritate the skin, mueous membranes or respiratory traet. Some ean promote skin or respiratory sensitization. The range of ehemieals in use is extremely wide, so that referenee should be made to the Materials Safety Data Sheet for eaeh speeifie formulation or variation of it identifiable by referenee to the supplier s proprietary name and eode number. Some eommon resin types are summarized in Table 5.55. 

Formaldehyde has been rated as a possible carcinogen by the United States Occupational Safety and Health Act (OSHA) rules and should be handled with due caution. It is also a strong lacrymator and choking respiratory irritant. It irritates the skin, eyes, and mucous membranes [76]. Since it is used for tanning leather, it is obvious that fonnaldehyde has a high potential for reactions with proteins. Formaldehyde gas is flammable and most formalin solutions contain significant amounts of methanol, which is also volatile, toxic, and flammable. 

Health Hazards Information - Recommended Personal Protective Equipment Self-contained breathing apparatus complete protective clothing safety glasses face shield Symptoms Following Exposure Inhalation causes severe irritation of upper respiratory system. Contact with liquid or vapor causes severe bums of eyes and can cause ulcers and blindness. Contact with skin causes severe burns. Ingestion causes severe burns of mucous membranes General Treatment for Exposure Get immediate... 

Health Efazards Information - Recommended Personal Protective Equipment Air-supplied mask in confined areas, mbber gloves, safety glasses Symptoms Following Exposure Vapor irritates mucous membranes and respiratory tract, causes nausea, vomiting, headache, and dizziness. Direct contact... 

---