Health risks

The third of the major hazards and the one with the greatest disaster potential is the release of toxic chemicals. The hazard posed by toxic release depends not only on the chemical species but also on the conditions of exposure. The high disaster potential from toxic release arises in situations where large numbers of people are briefly exposed to high concentrations of toxic material, i.e., acute exposure. However, the long-term health risks associated with prolonged exposure at low concentrations, i.e., chronic exposure, also present serious hazards. 

Today the demand for inspection of components with complex geometry, difficult access conditions or location in a hazardous environment is steadily increasing. Documentation, reproducibility and minimised health risk for the inspection staff are key issues. This leads to an increased demand for automated inspection, resulting in a need for new, advanced scarmer systems for NDE. 

When processed and used according to manufacturer s recommendations, acetal resins present no extraordinary health risks. Before the use of any plastic material, including acetal, the Material Safety Data Sheet (MSDS) appHcable to the grade in question should be consulted. 

Health Safety. PET fibers pose no health risk to humans or animals. Eibers have been used extensively iu textiles with no adverse physiological effects from prolonged skin contact. PET has been approved by the U.S. Eood and Dmg Administration for food packagiug and botties. PET is considered biologically iuert and has been widely used iu medical iaserts such as vascular implants and artificial blood vessels, artificial bone, and eye sutures (19). Other polyester homopolymers including polylactide and polyglycoHde are used iu resorbable sutures (19,47). 

Conduct Hazard Analysis and Risk Assessment. Ahazardis any biological, chemical, or physical property that may cause an unacceptable consumer health risk. AH of the potential hazards in the food chain are analyzed, from growing and harvesting or slaughtering to manufacturing, distribution, retailing, and consumption of the product. 

Determine Critical Control Points. A critical control point (CCP) is any point in the process where loss of control may result in an unacceptable health risk. A CCP is estabhshed for each identified hazard. The emergence of foodbome pathogens has taught food processors the importance of potential product contamination from the processing environment. 

Radiation at Nuclear Power Plants—What Do We Know About Health Risks EPRI, Palo Alto, Calif., Dec. 1994. 

H. Behling and co-workers, "Health Risks Associated with Low Doses of Radiation," TR-104070, Electric Power Research Institute, Palo Alto, Calif., Aug. 1994. 

Toxicity. The acceptable daily allowance, which may be ingested without any risk of harm, is 1050 mg for a 70-kg healthy person (20). There is also no evidence in the Hterature that ingestion of up to 10 g vitamin C per day constitutes a serious health risk for humans. 

Considerable effort has been devoted to finding alternative fibers or minerals to replace asbestos fibers ia their appHcations. Such efforts have been motivated by various reasons, typically, avadabihty and cost, and more recendy, health concerns. During Wodd War I, some countries lost access to asbestos fiber suppHes and had to develop substitute materials. Also, ia the production of fiber reiaforced cement products, many developiug countries focused on alternatives to asbestos fibers, ia particular on cellulose fibers readily available locally at minimal cost. Siace the 1980s however, systematic research has been pursued ia several iudustrialized countries to replace asbestos fibers ia all of their current appHcations because of perceived health risks. 

The search for asbestos replacement materials is obviously an ongoing process and further developments in this area are to be expected. The extent of substitution of asbestos fibers by other fibers or other materials has been limited by several factors, typically the availabiHty of adequate replacement materials, the cost performance ratio of such materials, and the uncertainty of long-term health risks of these replacement materials. From the data currendy available, it may be estimated that between 10—20% of the industrial consumption of asbestos fibers was diverted to other materials during the 1980s. 

Dust Inhalation. During processing, fine carbon filaments (5—10 p.m in diameter) may break and be circulated in the air as a carbon dust that can be inhaled by operators. Studies (71) show the fibers are too large to represent a respiratory health risk however they often create discomfort, and a protective mask is recommended when working in areas where carbon fiber dust is present. 

The fact that ceU culture-derived products are often injected into humans as therapeutic agents makes it imperative that there be no component in the final product that can pose a potential health risk to the patient. Health risks can be introduced into a product from many sources including the ceUs themselves raw materials, such as semm, media components, etc materials used in purification, eg, antibodies and external contamination. Eor a therapeutic product such risk factors are identified at the outset and ways of reducing them to acceptable levels are designed into the process. Before a product is released by the EDA the manufacturer has to demonstrate this risk reduction by rigorous validation of the process. 

L. P. Brown, D. G. Earrar, and C. G. DeRooij, Health Risk Assessment of Environmental Exposure to Trichloroethylene, Regulatory, Toxicol Pharmacol 11, 24-41 (1990). 

Ring Liners. Liners are either cellulose, which readily absorbs water, or ceramic, which does not absorb water or investment Uquid (123). Both are available in many si2es. Ceramic liners are made from fibers of alumino-siUcate glass derived from kaolin. The principal components in the glass are alumina, 47—65 wt %, and siUca, 35—50 wt %. Ceramic liners are highly heat resistant to 1300°C. Reports suggest that the fiber from ceramic ring liners may be a possible health risk (124). 

Modem liners are aU asbestos free because of the health risk associated with asbestos (qv). 

Like other proteins, enzymes are potential allergens. In addition, proteases may act as skin and eye irritants. However, during the production and handling of industrial enzymes, the occupational health risks entailed by these properties can be avoided by protective measures, and by the form in which... 

Ltindgren, Regina E., Risk Communication A Handbook for Communicating Environmental, Safety, and Health Risks, Battelle Press, Columbus, 1994. 

This chapter addresses the potential for hazardous air emissions from environmental remediation sites. These emissions can occur at hazardous spill locations, at undisturbed remediation sites, and during cleanup of remediation sites under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or the Superfund Amendments and Reauthorization Act (SARA). Air emissions may pose a potential health risk at these sites. 

In the UK alone occupational health risks due to chemicals are illustrated by ... 

Biologieal exposure indiees (BEI) published by the ACGIH are given in Table 5.13. BEIs represent the levels of determinant whieh are most likely to be observed in speeimens eolleeted from a healthy worker who has been exposed to ehemieals to the same extent as a worker with inhalation exposure to the TLV. Due to biologieal variability it is possible for an individual s measurements to exeeed the BEI without ineuning inereased health risk. If, however, levels in speeimens obtained from a worker on different oeeasions persistently exeeed the BEI, or if the majority of levels in speeimens obtained from a group of workers at the same workplaee exeeed the BEI, the eause of the exeessive values must be investigated and proper aetion taken to reduee the exposure. 

If leaks, spills or uneontrolled releases of a hazardous substanee eould oeeur, means are required for limiting the extent of health risks and for regaining adequate eontrol as soon as possible. Where appropriate means should inelude ... 

Health records must be kept of the health surveillance caiTied out for at least 40 years after the last entry. Appropriate action should be taken based upon the results, i.e. it should be established how and when workers should be referred for further examination and how the results will be used to improve the management of health risks. 

Catalysts are often used to inerease the rate of reaetions (Chapter 3). Like many ehemieals they ean pose health risks to workers (Table 5.28) unless handled with eare. They ean be either ... 

Clearly, flammable chemicals also pose a health risk if the substance or its thermal degradation... 

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