Solvents safety issues

Industrial solvent appHcations are broad, varied, and complex and each has its own set of characteristics and requirements. Proper solvent selection and blend development have a large impact on the success of the operation in which the solvent is used, from the perspectives of economic effects, technical adequacy, safety issues, and environmental impacts. 

Conventionally, analytical SEC columns have been produced with an internal diameter of 7.5 mm and column lengths of 300 and 600 mm. In recent years environmental and safety issues have led to concerns over the reduction of organic solvent consumption, which has resulted in the development of columns for organic SEC that are more solvent efficient (13). By reducing the internal diameter of the column, the volumetric flow rate must be reduced in order to maintain the same linear velocity through the column. This reduction is carried out in the ratio of the cross sectional areas (or internal diameters) of the two columns. Eor example, if a 7.5-mm i.d. column operates at 1.0 ml/min, then in order to maintain the same linear velocity through a 4.6-mm i.d. column the flow rate would be... 

Safety issues have been discussed comprehensively, in an earlier review [33]. At time of writing, more than two thousand reactions have been conducted with a range of solvents, times and temperatures in the CMR and MBR without accident or injury. 

Occupational health and safety in the rubber industry is discussed with reference to UK, US and European legislation. The review covers both natural and synthetic rubber industries. The first section outlines the laws affecting health and safety in the industry and the remainder presents specific health and safety issues of interest to employers and employees. Industrial safety is examined with reference to equipment, fire and explosions, solvents, epidemiology, NR latex allergy, skin irritations and dermatitis, dust and fume control, work-related musculoskeletal disorders, nitrosamines, 1,3-butadiene, and handling of rubber chemicals. 484 refs. 

Because solvents are required in such high volumes compared to all other materials used in a synthetic transformation, hazards associated with solvents and safety issues associated with their use have always been a consideration in the development and selection of solvents. Some of the earliest and most obvious hazards, that if solvents were found to possess would cause them to be selected against, include properties such as high flammability or explosivity. With the greater understanding of the health and environmental effects that could be caused by other hazardous properties that solvents may possess or by their use in such large volumes, alternative solvents are... 

Several existing protocols require a solvent (acetone, methanol, isopropanol) rinse as part of equipment decontamination for VOC sampling and 1 10 percent hydrochloric or nitric acid rinse for metal analysis sampling (DOE, 1996 USACE, 1994). These practices, successful as they may be in removing trace level contaminants, create more problems than they are worth. Organic solvents are absorbed by the polymer materials used in sampling equipment construction and appear as interferences in the VOC analysis. Acid destroys the metal surfaces of soil sampling equipment and induces corrosion. The use of solvents and acids is a safety issue and it also creates additional waste streams for disposal. 

Because of its high reactivity (—1.67 V vs. NHE), the electrodeposition of aluminum from aqueous solutions is not possible. Therefore, electrolytes for A1 deposition must be aprotic, such as ionic liquids or organic solvents. The electrodeposition of aluminum in organic solutions is commercially available (SIGAL-process [56, 57]) but due to volatility and flammability there are some safety issues. Therefore, the development of room-temperature ionic liquids in recent years has resulted in another potential approach for aluminum electrodeposition. Many papers have been published on the electrodeposition of aluminum from chloroaluminate (first... 

Perceived or Real Health and Safety Issues — There are a number of issues or perceived issues which customers encounter with the original MEK-based inks. The use of MEK has its share of concerns, based upon the smell and perception that it is a harmful material. Indeed, for this reason inks have been formulated with alternative solvents such as ethanol and methanol, as well as previously discussed acetone, and a variety of acetates, such as ethyl acetate. Some of these solvents have unpleasant odour, some more pleasant smell some have a lower toxicity level. That said, methanol is commonly used as a low odor replacement, but could probably be considered a more toxic ingredient Another component which is often replaced is the Solvent Black 29 dye, this dye does contain chromium as the counter ion and the toxicity concerns of having free Chromium 6 ions in an ink can be an issue for some applications or customers. Dyes with alternative counter ions or pigments have been chosen to replace this material. These requirements are often found in the food processing or pharmaceutical application areas, although they can occur with any customer. 

Safety issues are directly related to the solvent s flash point [6,16]. From this point of view, diethyl ether is the worst choice for a solvent (Table 1). Most industrial Grignard... 

In HPLC, a semiprep column might be operated at 25 mL/min, using up solvent and generating waste at a rate of up to 36 L/24-h day, or just under two 20-L containers of solvent in and two 20-L containers out as waste. Each week, the user needs to have available at least 10-14, 20-L containers of new solvent and must dispose of about 10-14 20-L containers of toxic, mixed waste for each chromatograph. Most jurisdictions limit the amount of solvent allowed in a lab at any given time as a fire safety issue. The limit is usually 50 L. A whole lot of barrel rolling occurs. 

Safety issues (besides solvents) - - Catalyst, H2 Catalyst,... 

There should be some periodic testing after cleaning, to assure that the surface has been cleaned to the validated level. One common method is the analysis of the final rinse water or solvent for the presence of the substance last used in that piece of equipment In some cases, visual inspections may be appropriate. A specific analytical method for the determination of residual substances may not always be available. The need for an analytical method would be based on the potential adverse effect on product quality, performance or safety. In case of a safety issue, there should always be a specific analytical determination for a residual substance. 

---