Naturally occurring hazardous chemicals

The classification system for hazardous chemical waste was developed independently of the radioactive waste classification system discussed in Section 4.1.2. In contrast to the classification system for radioactive waste, the classification system for hazardous chemical waste was not developed in recognition of the unavoidable risks from exposure to naturally occurring hazardous chemicals in the environment (see Section 6.3.1.2.1). 

Not all chemicals are considered as hazardous. Examples of nonhazardous chemicals include buffers, sugars, starches, agar, and naturally occurring amino chemicals. The following sections provide general guidelines for chemical safety. 

Accidents due to naturally occurring conditions resulting from the structure of tlie land or from tlie ravages of weatlier were reviewed briefly in Cluipter 5. Outdoor processing, coninion in industries using hazardous chemicals, increases... 

The known hazardous effects of most synthetic corrosion inhibitors are the reasons for the search of safer and environmentally friendly natural products. Plant extracts are viewed as an incredibly rich source of naturally synthesized chemical compounds that can be extracted at low costs. Naturally occurring substances such as vanillin [1], Opuntia extracts [2], lawsonia extract [3], natural honey [4] and extracts of chamomile, halfabar, black cumin and kidney bean [5] are some... 

Despite the nature of the environmental regulations and the precautions taken by the refining industry, the accidental release of nonhazardous chemicals and hazardous chemicals into the enviromnent has occurred and, without being unduly pessimistic, will continue to occur (by aU industries—not wishing to select the refining industry as the only industry that suffers accidental release of chemicals into the environment). To paraphrase chaos theory, no matter how well one prepares, the unexpected is always inevitable. 

The Remediation Technologies, Inc. (RETEC), slurry-phase bioremediation (liquid-slurry treatment) is an ex situ technology that uses naturally occurring bacteria to breakdown hazardous organic chemicals. The degradation process occurs in an engineered reactor, such as a lined lagoon, tank, or other similar vessel. 

Just as chemists are needed to fully understand the nature and source of environmental problems that result from certain chemicals of concern released to the environment, chemists are also required to use that understanding in preventing problems from occurring in the first place. For a wide array of chemicals, the activity of a chemical of concern in the environment can be related to the molecular structure of the chemical, that is, how the atoms of the molecule are connected. Through a combination of knowledge of the nature of a chemical s hazardous properties with the ability to manipulate the chemical s structure, chemists possess the ability and skill to mitigate the hazard. 

Approach to dealing with naturally occurring chemicals Aesthetic effects Common health hazards... 

Microbial hazards make the largest contribution to waterborne disease in developed and developing countries, Nevertheless, chemicals in water supplies can cause serious health problems - whether the chemicals are naturally occurring or derive from sources of pollution. At a global scale, fluoride and arsenic are the most significant chemicals, each affecting perhaps millions of people, However, many other chemicals can be important contaminants of drinking-water under specific local conditions. 

Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is referred to as stable strontium. Stable strontium in the environment exists in four stable isotopes, " Sr (read as strontium 84), Sr, Sr, and Sr. Twelve other unstable isotopes are known to exist. Its radioactive isotopes are Sr and °Sr. Strontium is chemically similar to calcium. It was discovered in 1790. The isotope Sr is a highly radioactive poison, and was present in fallout from atmospheric nuclear explosions and is created in nuclear reactors. Atmospheric tests of nuclear weapons in the 1950s resulted in deposits and contaminations. °Sr has a half-life of 28 years and is a high-energy beta emitter. Its common cationic salts are water soluble it forms chelates with compounds such as ethylenediaminetetraacetic acid strontium coordination compounds are not common. Powdered metallic strontium may constitute an explosion hazard when exposed to flame. 

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