Safety concerns

The general safety concerns in the HPLC Lab are in-line with most analytical laboratories dealing with small sample sizes.10 The high-pressure operation of the HPLC instrument usually does not pose a significant safety risk since small volumes of liquids are used and the units are designed for these conditions. Typical safety risks involve external conditions such as high electric voltages in close proximity with the mobile phase, which can be a flammable or combustible liquid. The operation and set-up of HPLC modules should be in compliance with local, state, and national fire codes such as NFPA 30, NFPA 45, and/or NFPA 70 (National Electrical Codes). 

As a general rule, the following practices should be considered when handling mobile phase solvents  

The potential danger for flask implosion during vacuum filtration and degassing should be noted. This danger can be substantial when vacuum fil- 

The history of technology reveals that safety and risk issues have often been handled with a mixture of attitudes and approaches, including consideration of the following (Sorensen, 1982). 

A well-known case is the detrimental influence on the development and use of hydrogen in the transportation industry caused by the Hindenburg accident in 1936. The Zeppelin company chose to blame hydrogen for the accident, although they seemed to have known that the cause was the use of a 

Photo from accident report No. 2 (1984) by Svenska Miljoverket the photo is in public domain as confirmed by Stockholm County Police. Hydrogen canisters are encircled in black. 

Industrial use of hydrogen has experienced a few accidents, which subsequently have been useful in defining norms and procedures. One occurred in a narrow Stockholm street in 1983, where 13.5 kg of H2 escaped from a set of 20-MPa pressure tanks with defect cormections and exploded (Fig. 5.4a) 16 people were injured, and 10 cars and the adjacent building were heavily damaged. This accident has recently been modelled by computational fluid dynamics methods, giving the distribution of H2 velocities and concentra- 

It is certainly my experience that the most common and catastrophic accidents in process units are related to corrosion-type failures. 1 cannot bring to mind any process vessels that were definitely overpressured and failed because a relief valve did not open. 

Relief valves were invented to prevent steam boilers from blowing up as a result of excessive steam drum pressure. This was a distressingly common occurrence in the nineteenth century. The relief valve is also called a safety (or pop ) valve. When the pressure in a vessel exceeds a preset amoimt, the relief valve is supposed to pop or spring open. Gas will then be vented from the vessel imtil the pressure in the vessel drops by 10 to 20 psi below its relief-valve-set pressure. We usually operate pressure vessels at 25 psig or 10 percent below the relief-valve setting. 

The relief-valve-set, or pop, pressure is adjusted in a machine shop. A large threaded nut on top of the relief valve is used to make this adjustment. Air pressure is applied to the valve, and the technician adjusts this nut until the relief valve opens at the proper pressure. 

The pressure at which relief valves are set to open is the vessel design pressure. The vessel design pressure (maximum allowable working pressure, MAWP) is stamped on the manufacturer s nameplate. It is illegal to set the relief valve at a higher pressure. The vessel is probably hydrostatically tested at a pressure 50 percent greater than its 

On the other hand, vessels must often be derated for age and excessive corrosion. Either way, the relief valve needs to be reset. There is only one way to know the actual relief-valve setting, and that is to climb up to the relief valve and read the tag that was fixed to the valve at the time of its last setting. 

The most important criterion for solvent selection is throughput, which mainly depends on a sufficient solubility of the solutes and the corresponding selectivity of the separation. Because solubility and selectivity depend on the interaction between the three elements of the chromatographic system, the selection of the mobile phase dependent on these parameters is further discussed in Sections 3.2.3-3.2.8. 

The stability of all components of the chromatographic system must be assured for the complete operation time. The solvent must be chemically inert towards all kinds of reaction. Neither an instable solvent, which for example tends to form peroxides, nor a solvent that reacts with the sample or the adsorbent is suitable for an economically successful solution of the separation problem. Of course, corrosion of the HPLC unit must be prevented, too. 

In chromatographic systems operated with a high percentage of water or buffer the microbial contamination of the solvent has to be carefully monitored. 

The safety of preparative processes depends on the flammability and toxicity of the solvent. Owing to the huge amounts of solvents handled in preparative chromatography, low flammability should be preferred. Flammability is described by the vapor pressure, the explosion limits, or the temperature class of the solvent. Generally, the use of flammable solvents can not be avoided and thus the risk must be minimized by good ventilation and other precautions in the laboratory. 

Solvent Solvent strength Boiling point (°C) Viscosity25 c (cP) Rl(-) 

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In comparison with most other analytical techniques, radiochemical methods are usually more expensive and require more time to complete an analysis. Radiochemical methods also are subject to significant safety concerns due to the analyst s potential exposure to high-energy radiation and the need to safely dispose of radioactive waste. 

The separation of cells from the culture media or fermentation broth is the first step in a bioproduct recovery sequence. Whereas centrifugation is common for recombinant bacterial cells (see Centrifugal separation), the final removal of CHO cells utilizes sterile-filtration techniques. Safety concerns with respect to contamination of the product with CHO cells were addressed by confirming the absence of cells in the product, and their relative noninfectivity with respect to immune competent rodents injected with a large number of CHO cells. 

Health and safety concerns in the stmctural composite lumber industry are similar to those in the other composite industries. Special care is required in worker awareness, worker protection equipment, dust and vapor control, and general housekeeping. 

The safety review report is distributed to the committee which meets to work its way through the report, section by section, discussing safety concerns and potential improvements to the process or procedure. An individual must be designated to take minutes at the meeting and record suggested modifications. If the review concerns an existing process, the committee should perform a site visit to examine the actual equipment. 

This article discusses several aspects of processed meat products including (/) health and safety concerns (2) meat processing ingredients, procedures, and machinery (J) ha2ard analysis critical control point (4) fat reduction in meat products (5) sous-vide processing and (6) nutritional labeling. 

Outlook. Total 1991 U.S. ink consumption was estimated at about 86 x 10 kg valued at over 3.0 biUion. The demand is estimated to grow at an average of about 3—4% per year in volume (26). The principal changes expected in the 1990s will continue to be in response to environmental and safety concerns and government regulations. The bulk of printing inks use raw materials based on fossil fuels, such as coal (qv) and petroleum (qv). 

Principal health and safety concerns involve contact with foodstuffs and dmgs. U.S. government regulations governing the use of additives such as... 

Sealant Manufacturing. Most sealants use mineral-based fillers which may contain small amounts of crystalline siHca. If crystalline siHca is present, dust control is important to prevent inhalation of these particles. Crystalline siHca is a known cause of siHcosis, a debiHtating disease of the lung. Another common safety concern in sealant manufacturing is the use of flammable materials. Not all sealants use flammable ingredients, but for those that do, proper inerting and grounding are needed to prevent potential explosions. 

Sensors form a very broad-based, multihilHon doUar business. Detailed information and predictions of the growth in the many sensor subftelds can be found in the Hterature (39). Eor example, the relatively narrow area of acceleration and vibrations sensors was a 600 million business in 1995 and projected to become a 1 biUion business by the end of the twentieth century. New appHcations, often driven by regulatory and safety concerns, mean projected growth of just about every sensor type. 

Like brines, alcohols were readily available and widely used as antifreeze Hquids in the early 1900s. Both methanol and ethanol offer exceUent heat transfer and efficient freeze point depression. However, the alcohols have the distinct disadvantage of their low boiling points. During the summer months when the engines operate hot, significant amounts of the alcohols are lost because of evaporation. These evaporative losses result in cosdy make-up requirements. Additionally, the alcohols have very low flash points and potentially flammable vapors. These safety concerns have, particularly in recent years, caused the use of alcohols to be completely discontinued for most heat-transfer systems. 

The principal safety concern in handling molten benzoic acid is its elevated temperature. Thermal bums may result from improper handling of the molten product (25,26). 

The earliest method for manufacturiag carbon disulfide involved synthesis from the elements by reaction of sulfur and carbon as hardwood charcoal in externally heated retorts. Safety concerns, short Hves of the retorts, and low production capacities led to the development of an electric furnace process, also based on reaction of sulfur and charcoal. The commercial use of hydrocarbons as the source of carbon was developed in the 1950s, and it was still the predominate process worldwide in 1991. That route, using methane and sulfur as the feedstock, provides high capacity in an economical, continuous unit. Retort and electric furnace processes are stiU used in locations where methane is unavailable or where small plants are economically viable, for example in certain parts of Africa, China, India, Russia, Eastern Europe, South America, and the Middle East. Other technologies for synthesis of carbon disulfide have been advocated, but none has reached commercial significance. 

Acetjiene has found use as a feedstock for production of chlorinated solvents by reaction with hydrogen chloride or chlorine (6). However, because of safety concerns and the lower price of other feedstock hydrocarbons, very Htfle acetylene is used to produce chlorinated hydrocarbons in the United States (see Acetylene-derived chemicals). 

Safety. While steam burns are fairly common, there are generally fewer safety concerns than with electric tracing. 

Identify safety concerns unique to batch reaction systems ... 

It is a good practice to ensure that both the toller and client have records of the complete incident and accident history for the toll. This information can be vital to the industry as a database of experience with the tolled process. Process safety concerns for future tolls of the product or related materials can benefit from this practice. 

The pursuit of product quality over the last few decades has been intense in many companies around the world, but in many sectors of industry, reliability is considered to be the most important quality attribute of the product (Kehoe, 1996). As consumers become more aware than ever of quality, their expectations for reliability are also increasing. Even equipment without obvious safety concerns can have important reliability implications. Most products can, therefore, benefit from the use of sound reliability techniques (Burns, 1994). Reliability prediction, in turn, has the benefit that it gives a quantifiable estimate of the likely reliability that can be assessed to see if this is appropriate for the market (Stephenson and Wallace, 1996). 

Natural gas is the fuel of choice wherever it is available because of its clean burning and its competitive pricing as seen in Figure 1-30. Prices for Uranium, the fuel of nuclear power stations, and coal, the fuel of the steam power plants, have been stable over the years and have been the lowest. Environmental, safety concerns, high initial cost, and the long time from planning to production has hurt the nuclear and steam power industries. Whenever oil or natural gas is the fuel of choice, gas turbines and combined cycle plants are the power plant of choice as they convert the fuel into electricity very... 

Because of safety concerns, all combustible and/or toxic gases must be used in outdoor test loops or in a special indoor test building with the required safety monitoring equipment. The gas cost factor makes the problem even more difficult. The problem of known gas properties adds another complication. Despite all the negative aspects just mentioned, most performance tests are closed-loop tested. 

Free phenol is a major concern in the manufacture of novolac resins. This is true for several reasons. The strongest drivers are probably EPA classification of phenol as a Hazardous Air Pollutant and worker safety concerns. However, free phenol also has significant technical effects on such parameters as melt flow characteristics. In this role, free phenol may undermine the desired effects of a molecular weight design by increasing flow beyond the desired point. Since free phenol is often variable, the effects on flow may also cause variation in product performance from batch to batch. Fig. 18 shows the effects of free phenol on the flow across a series of molecular weights. Free phenol contents between 1 and 10% are commonly seen. In recent years, much work has been aimed at reducing the free phenol. 

Evaluate (proposed) tasks to verify that the safety concerns are adequately addressed... 

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