Harmful substances

Substances have to be classified as harmful if moderate amounts can have fatal effects or cause severe health problems. The labeling of harmful substances and preparations has to be done with the dedicated R-phrases and the hazard symbol St. Andrew s Cross (Xn) with the indication of danger harmful . The exact criteria are summarized in Table 3.6. 

The following R-phrases have to be used in order to express the application route  

Many important industrial chemicals are classified as harmful, e.g., the organic compounds toluene, glycols, cyclohexanol, benzyl alcohol, benzaldehyde, maleic anhydride, isobutyric acid, the inorganic compounds iodine, brownstone (manganese dioxide), dimercury dichloride (calomel), vanadium pentoxide, and many compounds of copper and cobalt (see Fig. 3.4). 

Compounds with a lethal dose of above 2000 mg kg (= 2 g kg ) body weight are, from experience, not able to lead to any harm and are therefore not classified as dangerous compounds. Of course, if swallowed in greater amounts over a longer period or in extremely high amounts in a single dose, severe health effects can happen. Table 3.7 summarizes the acute toxicity of some foods. 

Substances which lead to severe, non-fatal health effects on acute application in the doses mentioned in Table 3.6 are also classified as harmful. To distinguish them from the substances classified as category three mutagens, the application route has to be added after the slash  

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Pollutants. The problems posed by ak pollutants are very serious. Within a museum, measures can be taken to remove harmful substances as efficiently as possible by means of the installation of appropriate filter systems in the ventilation equipment. Proposed specification values for museum climate-control systems requke filtering systems having an efficiency for particulate removal in the dioctyl phthalate test of 60—80%. Systems must be able to limit both sulfur dioxide and nitrogen dioxide concentrations <10 /ig/m, and ozone to <2 /ig/m. ... 

Estimating the long-term risk to workers or the public from chronic exposure to potentially harmful substances or activities... 

Toxic air pollutants are pollutants which are hazardous to human health or the environment but which are not specifically regulated by the CAA. These pollutants are typically carcinogens, mutagens, and teratogens. The CAAA of 1977 failed to result in substantial reductions in the emissions of these harmful substances. 

H5 Harmful substances and preparations which, if they are inhaled or ingested or if they penetrate the skin,... 

A pesticide formulation plant should prepare and implement an emergency preparedness and response plan that takes into account neighboring land uses and the potential consequences of an emergency or accidental release of harmful substances. Measures to avoid the release of harmful substances should be incorporated in the design, operation, maintenance, and management of the plant. Pollution control equipment employed in this sector include baghouses for removal of particulate matter and carbon adsorption for removal of VOCs. 

An exception may be made when there is good reason to believe that the chief effects of the different harmful substances are not in fact additive, but independent, such as a combined exposure to silica dust and lead dust. In the determination of whether or not the additive effects are excessive, the following formula should be used ... 

Goldschmidt, G., and P. Filskov (1990). Substitution— A Way to Obtain Protection Against Harmful Substances at Work. Staub-Reinhahund Der Luft 50, 403-5. 

The new hand protection standard resulted from OSHA s belief that many hand injuries result from not wearing hand protection or wearing protection for the wrong type of hazards. Employers should evaluate and provide hand protection when there are hazards to hands from absorption of harmful substances, severe cuts or lacerations, severe abrasions, punctures, chemical burns, thermal burns, and harmful temperature extremes. 

Since the early days of using PVC separators in stationary batteries, there has been a discussion about the generation of harmful substances caused by elevated temperatures or other catalytic influences, a release of chloride ions could occur which, oxidized to perchlorate ions, form soluble lead salts resulting in enhanced positive grid corrosion. Since this effect proceeds by self-acceleration, the surrounding conditions such as temperature and the proneness of alloys to corrosion as well as the quality of the PVC have to be taken carefully into account. 

PP potentially harmful substances. PXR appears to be the key regulator of CYP3A induction by xenobiotics. 

Methyl parathion can enter your body if you eat food or drink water containing it if you swim, bathe, or shower in contaminated water if you touch recently sprayed plants or soil if you touch contaminated soil near hazardous waste sites or if you breathe air that contains methyl parathion, such as near factories or recently sprayed farm fields (or in recent accounts of the illegal use of methyl parathion, if you breathe air or touch contaminated surfaces inside homes where methyl parathion has been used to kill insects). By any means of exposure, methyl parathion goes into your body quickly and gets into your blood. From your bloodstream, methyl parathion goes to your liver, brain, and other organs. Your liver changes some of methyl parathion to a more harmful chemical called methyl paraoxon. Both methyl parathion and methyl paraoxon can bind to enzymes of your nerves within minutes or hours. Your liver breaks down methyl parathion and methyl paraoxon into less harmful substances. These less harmful substances leave your body in urine within hours or days. For more information, see Chapter 3. 

MITI is currently undergoing research to develop technology for the recycling of non-flammable plastics such as those used in business machines and computers. Their National Institute for Resources and Environment plans to decompose, without the production of harmful substances, non-flammable polymers by means of liquid phase hydrocracking, and to recover from them light oils such as benzene, toluene and xylene. The key to the technology, it is claimed, lies in the development of a catalyst which will be able to combine hazardous substances such as bromine and chlorine contained in the waste plastics. 

When bacteria or almost any organism are exposed to high temperatures, the synthesis of a set of HSPs encoded by heat shock genes is rapidly and transiently induced this reaction has been designated as the heat shock response. Later, it was foimd that most heat shock genes are not only induced by heat, but by many other stress regimens (Table 1). The stress factors have been classified into three groups physicochemical factors, metabolically harmful substances and complex metaboHc processes. Therefore, the heat shock is often called the stress shock to comply with these observations. 

Destruction, detoxification, neutralization, etc. of wastes into less harmful substances... 

Another biological disadvantage is that dental silicate cement does not bond to tooth material, and harmful substances and bacteria can percolate between it and the tooth, giving rise to secondary caries and pulpal irritation (Going, Massler Dute, 1960). These effects are magnified when dissolution of the cement occurs. 

Avoid harmful substances that could be released at end of life. 

Ensure any harmful substance can be easily extracted from the product. 

The effect of a harmful substance obviously depends on the quantity the person is exposed to. This quantity is expressed in air concentration and exposure time for a gas and the subject weight for liquids and solids. 

In France these correspond to what is decided by the European UnionT The codes used for inflammable, unstable substances and for some risks linked to reactivity have already been described. There are numerous codes for toxicity and comosive-ness and these have the skull as a symbol for toxic substances, an X for harmful substances pabout risk and some cautionary advice that bear numbers preceded with the letter R, and sentences about risk and S for cautionary advice. Everything has to appear on the container labels. Cautionary advice has never seemed coherent or sufficiently exhaustive and only risk codes are mentioned in Part Three. Notes on risk appear in the following tabie. 

Indianapolis regulates the use of DDT by requiring that food and utensils be protected during spraying. This is required under the authority vested in the health officer to regulate the use of harmful substances, including residual sprays. 

In time, however, some of these scientific discoveries—even those that in their day made major reforms—produced their own set of difficulties. In each case where this occurred, the burden of identifying and solving the problem fell to science. Consumers clamored for new products, but they also demanded that governments and industry protect the air, water, soils, plants, and animals endangered by human-made chemicals. As pollutants became increasingly subtle and harder to detect, scientists became leaders in identifying harmful substances, in some cases before the public was even aware of their existence, much less their potential harm. In these stories, advances in science have both created new and needed products and dealt with pollution from the past. 

In addition to the aforementioned issues regarding the incineration process, other concerns of relevance to public health need to be addressed. For example, hazardous waste to be fed to the incinerator and process effluents resulting from the incinerator should be stored in a manner that does not allow for uncontrolled environmental releases of potentially harmful substances. Dry, dusty materials should be enclosed or otherwise stored to prevent windborne transport of contaminated particulates. Wastes containing volatile organic compounds should be stored under conditions that safely collect and remove gases released from the wastes. 

MPC (maximum permissible concentration) — the highest concentration of a harmful substance in the environment (air, water, and soil), where this substance does not act unfavorably in the human body over an unlimited length of time. 

ASLI (approximate safe level of impact) — the temporary approximate health regulation of the content of harmful substances in the air of workplaces and population points, in the water in reservoirs, and in food products. Used for preventive health supervision. Established using mathematical equations. 

The long-term widespread use of DDT over a number of years demonstrates one typical Soviet trick - abusing loopholes in the rules. DDT was actively used for decades, while not being on lists of permitted substances, a situation condoned by the Health and Epidemiological Services and their on-site agencies. Pesticide use systematically was not in accordance with the permissible standards in the USSR. In 1976 the USSR introduced a System of Labor Safety Standards Harmful Substances, Classification and Overall Safety Requirements, according to which all harmful substances were broken down into four risk classes, taking into account several different indices (table 1.5). 

MPL (Maximum Permissible Level) - the maximum concentration of harmful substances in food products that does not cause illness or deviations in the health of those ingesting these products, or cannot negatively affect the next generation. 

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