Working with Chemicals

Some occupational hygiene aspects of man-made mineral fibres and new technology fibres Safe handling requirements dunng explosive, propellant and pyrotechnic manufacture Simplified calculations of blast induced injuries and damage Laboratory work with chemical carcinogens and oncogenes Rosin (colophony) a review... 

When working with chemicals that have target organ effects it is critical to prevent exposure. This is especially true if you have a pre-existing condition, disease, or injury to that particular organ. Read the MSDS to fmd out the most effective personal protection equipment (PPE) for dealing with the chemical and be certain to minimize release of the chemical in the first place. 

This serves as a reference for Uiose working with chemicals to check and see if the chemicals being used are hazardous. 

Two other terms that you will come across when working with chemical data are repeatability and reproducibility. Again, these two terms can easily be confused and you should learn to distinguish between them. They are both measures of precision. 

The effect of a detonation depends on the shock wave, that is, an immediate peak overpressure followed by a longer period with an underpressure. The strength of the shock wave depends on the mass of the detonating materials. Detonations are mostly induced by initiation sources. In some cases, a deflagration may make a transition into a detonation. Working with chemicals and systems under plant conditions where a detonation can be induced is NOT recommended. Whether or not a chemical or chemical system can detonate can be determined only by specific tests as outlined in Chapter 2. 

MRC (1981). Guidelines for Work with Chemical Carcinogens in Medical Research Council Establishments, Medical Research Council, London. 

Fume hoods must be used when working with chemicals that may produce hazardous fumes. 

The relationship above gives a way of converting from grams to moles to particles, and vice versa. If you have any one of the three quantities, you can calculate the other two. This becomes extremely useful in working with chemical equations, as we will see later, because the coefficients in the balanced chemical equation are not only the number of individual atoms or molecules at the microscopic level, but also the number of moles at the macroscopic level. 

The key to safe handling of chemicals is a good, properly installed hood, and the referenced book devotes many pages to hoods and ventilation. It recommends that in a laboratory where people spend much of their time working with chemicals there should be a hood for each two people, and each should have at least 2.5 linear feet (0.75 meter) of working space at it. Hoods are more than just devices to keep undesirable vapors from the laboratory atmosphere. When closed they provide a protective barrier between chemists and chemical operations, and they are a good containment device for spills. Portable shields can be a useful supplement to hoods, or can be an alternative for hazards of limited severity, e.g., for small-scale operations with oxidizing or explosive chemicals. 

A. G. Ekstrand, in his biography of Nilson written for the Swedish Academy of Sciences, expressed admiration that A person can work with chemicals and chemical apparatus in such a neat and truly elegant manner as he does. In the laboratory at Upsala, where I worked beside him for many years, I cannot recall ever having seen him in a laboratory coat (34). Ekstrand described Nilson as a practical chemist, not much given to theorizing. 

Biosafety procedures When working with chemicals, suitable protective wear, such as lab coat and disposable gloves, are advised. When human serum specimens are involved, experiments must be conducted in accordance to the standard biosafety procedures as instructed by the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO). 

The purpose of this monograph is to make chemists and those working with chemicals aware of the practical aspects—the existance and dangers--of chemical teratogenesis. Chemicals are unavoidable in the modern world. Chemical industry employs numerous women. 

M.E. Green and A. Turk, "Safety in Working with Chemicals", McMillan, New York, N.Y., 1978. 

This is a very moving film about a 17-year-old boy in isolation. He can only receive guests while wearing a helmet with an air purification system. Ever since childhood he has had to wear an air purification device on his back. At home, he makes use of various air purification devices and always carries around a hose which supplies purified air. He has not been outside in more than eight years. He has DNA deficiencies and his father worked with chemical substances, which according to the movie accounts for this boy s disorders. 

Some applications are listed to illustrate these potentials. They may be classified in various ways. The most direct approach consists in working with labelled (deuterated), model systems. Real materials (designed for industrial applications and processed at a large scale) are often multicomponent, complex systems, which may be relatively ill defined at the molecular scale. Thus, working with chemically well defined, labelled materials (which, however, often have relatively poor mechanical properties by themselves) is a way to isolate and study the various parameters which play a role in rubber properties. Studies are done both in the relaxed state and in constrained (uniaxially deformed) states. This approach is illustrated in Section 15.3. Examples of studies performed in model, single component networks are presented. However, even in this case, the sensitivity of the method is such that it may detect the presence of a few percent of molecular defects. 

Human activities are associated with the use and disposal of a variety of chemicals and chemical products. This is the situation for a householder, a laboratory student, and also the industry worker. Many materials have properties that make them hazardous. They can create physical (fire, explosion) or health hazards (toxicity, chemical bums). However, there are many ways to work with chemicals which can both reduce the probability of an accident and reduce the consequences should an accident occur. Risk minimization depends on safe practices, appropriate engineering controls for chemical containment, the proper use of personnel protective equipment, use of the least amount of material necessary, and substitution of a less-hazardous chemical for a more hazardous one. Before beginning any chemical processing or operation, ask What would happen if. .. The answer to this question requires understanding of the hazards associated with chemicals, the equipment, and the procedure involved. The hazardous properties of the material and its intended use will dictate the precautions to be taken. 

Always follow these guidelines when working with chemicals in laboratory ... 

Throughout history, the chemical and pharmaceutical industries have gained mind-boggling unexpected experience in the hazards of working with chemicals. The safety literature provides a sobering and dark commentary with regard to explosions, runaway reactions, fires, toxic emissions, asphyxiations, spills, and so on, and their consequences. Consequences are seen in the injuries and deaths of people and in physical, social, and environmental damage around the world. 

This chapter provides an introduction, which, hopefully, will enable chemists and engineers to appreciate the major Safety/Health issues faced by people working with chemicals. The most immediately devastating are obviously explosion and fire. Adverse health effects resulting from the exposure of people to certain chemicals can also be immediate (e.g., exposure to methyl isocyanate in Bhopal), but health effects can also take time to manifest themselves. In view of the unknowns, it is best to maintain caution in all situations even though, putting matters into perspective, exposure to many chemicals (solvent vapors are the most common) can be tolerated... 

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