Mothballs

However, in spite of these developments the market for the synthetie polymer has proved disappointing and many plants in the Western world have been mothballed . The greatest use appears to be in the one-time Soviet Union, where it was developed to avoid dependenee on the natural material. 

Plants should be emptied before they are mothballed or left for dismantling. Apart from the hazard just described, water can freeze and rupture lines (see Section 9.1.1). 

Coal slurry pipelines have been widely discussed, but few slurry pipelines have been built. In addition to the Black Mesa operation in Arizona, a 38-mile (61-km) pipeline was built by the Soviet Union, and a 108-mile (173-km) pipeline in Ohio was mothballed in 1963 after six years of operation. It is arguable to what extent the limited use of slurry pipelines is due to economics or to political opposition from rail car-... 

After 1973 the United States invested heavily in synthetic fuel research and development, hoping synthetics could sciwc as economical substitutes for crude oil. However, coal conversion is not profitable unless the price of crude oil is over 50 per barrel, which is why the processes developed were mothballed when world crude oil prices fell in the 1980s. 

William Thomas Brantle (17B8-1866) was born in London, England. Trained as an apothecary, he became a lecturer in chemistry at the University of London in 1808 and was a professor at the Royal Institution from 1813 to 1852. His scientific achievements were modest, although he was the first person to discover naphthalene, now used in mothballs. 

Liquids with high vapor pressures at ordinary temperatures are said to be volatile. Methanol (vapor pressure 98 Torr at 20°C) is highly volatile mercury (1.4 mTorr) is not. Solids also exert a vapor pressure, but their vapor pressures are usually much lower than those of liquids because the molecules arc gripped more tightly in a solid than they are in a liquid. Nevertheless, solids vaporize in the process called sublimation (Section 6.11), which we can observe in the presence of some pungent solids—such as menthol and mothballs. 

Suppose that 10.0 g of an organic compound used as a component of mothballs is dissolved in 80.0 g of benzene. The freezing point of the solution is 1.20°C. (a) What is an approximate molar mass of the organic compound (b) An elemental analysis of that substance indicated that the empirical formula is C3H2C1. What is its molecular formula (c) Using the atomic molar masses from the periodic table, calculate a more accurate molar mass of the compound. 

The structures of some PAHs of environmental interest are given in Figure 9.1. Naphthalene is a widely distributed compound consisting of only two fused benzene rings. It is produced commercially for incorporation into mothballs. Many of the compounds with marked genotoxicity contain 3-7 fused aromatic rings. Benzo[a] pyrene is the most closely studied of them, and will be used as an example in the following account. 

Fusion and vaporization are the most familiar phase changes, but sublimation is also common. Sublimation is a phase change in which a solid converts directly to a vapor without passing through the liquid phase. Dry ice (solid CO2) sublimes at 195 K with A ii/subl — 25.2 kJ/mol. Mothballs contain naphthalene (Cio Hg,... 

Anne Stewart emerges from a deep cupboard and sees my faint grin. She looks over my shoulder as she goes past behind me with a whiff of mothballs and brass polish. "Is that handwriting Strange, in a proper book. ... 

Formulate hypothesis This leads to your hypothesis that the sample consists of naphthalene (i.e., mothballs) dissolved in a petroleum product. 

Commentary Ultimately, solving this problem was rather straightforward once the characteristic odor of mothballs was noted. (Keep in mind the safety aspects of smelling unknown chemicals, especially pesticides.) During the information gathering stage, perhaps interviews with elderly residents or perusal of the local newspaper at the time may have provided additional information to guide the analysis. 

Material allowed to remain in, or inadequately cleaned out of, mothballed or decommissioned equipment. 

Monitoring active, management practices, 114 Mothballing, chemical reactivity hazard management, 25... 

There are indications that pure naphthalene (a constituent of mothballs, which are, by definition, toxic to moths) and alkylnaphthalenes are from three to 10 times more toxic to test animals than are benzene and alkylbenzenes. In addition, and because of the low water solubility of tricyclic and polycyclic (polynuclear) aromatic hydrocarbons (i.e., those aromatic hydrocarbons heavier than naphthalene), these compounds are generally present at very low concentrations in the water-soluble fraction of oil. Therefore, the results of this smdy and others conclude that the soluble aromatics of crude oil (such as benzene, toluene, ethylbenzene, xylenes, and naphthalenes) produce the majority of its toxic effects in the enviromnent. 

The application of robotics to enhance laboratory productivity has met with some success with many early adapters and in laboratories with high-volume repetitive routine assays. However, the requirements for extensive installation, development, validation and continuing maintenance effort have slowed the growth of robotics in pharmaceutical laboratories. Many robots in pharmaceutical R D labs have been abandoned or mothballed because they were not sufficiently flexible or reliable at... 

Clear, colorless, flammable liquid with a sweet almond, medicinal or mothball-like odor. An odor threshold concentration of 210 ppbv was reported by Leonardos et al. (1969). At 40 °C, the lowest concentration at which an odor was detected was 190 pg/L. At 25 °C, the lowest concentration at which a taste was detected was 190 pg/L (Young et al, 1996). The average least detectable odor threshold concentration in water at 60 °C was 0.08 mg/L (Alexander et al, 1982). Cometto-Muhiz and Cain (1994) reported an average nasal pungency threshold concentration of 10,553 ppmv. 

Uses Intermediate for phthalic anhydride, naphthol, 1,4-naphthoquinone, 1,4-dihydro-naphthalene, 1,2,3,4-tetrahydronaphthalene (tetralin), decahydronaphthalene (decalin), 1-nitro-naphthalene, halogenated naphthalenes, naphthol derivatives, dyes, explosives mothballs manufacturing preparation of pesticides, fungicides, detergents and wetting agents, synthetic resins, celluloids, and lubricants synthetic tanning preservative emulsion breakers scintillation counters smokeless powders. 

The chemical 1,4-di chlorobenzene is usually called para-DCB or p-DCB, but there are about 20 additional names for it, including para crystals and paracide. It is also called paramoth because it is one of two chemicals commonly used to make mothballs. 1,4-Dichlorobenzene is used to make deodorant blocks used in garbage cans and restrooms, as well as to help control odors in animal-hoi ding facilities. 1,4-Dichlorobenzene has also been used as an insecticide on... 

At room temperature, 1,4-dichlorobenzene is a white solid with a strong odor that you would probably recognize as the smell of mothballs. When a package of 1,4-di chlorobenzene is opened, it slowly changes from a solid into a vapor and is released into the atmosphere. The released vapor acts as a deodorizer and insect killer. Most of the 1,4-di chlorobenzene that is released to the general environment is present as a vapor. 1,4-Dichlorobenzene can burn, but does not burn easily. Most people begin to smell 1,4-di chlorobenzene when it is present in the air at a concentration of 0.18 parts per million (ppm) and in water at a concentration of 0.011 ppm. 

Humans are exposed to 1,4-dichlorobenzene mainly by breathing vapors from 1,4-dichlorobenzene products used in the home, such as mothballs and toilet-deodorizer blocks. Reported levels of 1,4-dichlorobenzene in some homes and public restrooms have ranged from 0.29 to 272 parts of 1,4-di chlorobenzene per billion parts (ppb) of air. Outdoor levels of 1,4-dichlorobenzene are much lower, and reported levels in cities range from 0.02 to 20 ppb. Even levels in the air around hazardous waste sites are low reported levels range from 0.03 to 4.25 ppb. 

There is also a possibility that 1,4-di chlorobenzene used in the home can be accidentally swallowed, especially by young children. When 1,4-di chlorobenzene is used in mothballs or deodorant blocks, these products may be freely available in closets or bathrooms. 

Children are exposed to 1,4-di chlorobenzene in many of the same ways that adults are. There is a possibility that 1,4-di chlorobenzene used in the home can be accidentally swallowed, especially by young children. When 1,4-di chlorobenzene is used in mothballs or toilet bowl deodorant blocks, these products may be freely available in closets or bathrooms. Although most of the exposure pathways for children are the same as those for adults, children may be at a higher risk of exposure because of their lack of consistent hygiene practices and their curiosity about unknown powders and liquids. 

You and your children can be exposed to 1,4-di chlorobenzene in your home if you use products such as 1,4-dichlorobenzene-treated toilet bowl cleaners or mothballs containing 1,4-dichlorobenzene. You should not let your child play with or drink toilet bowl water that has been treated with 1,4-di chlorobenzene. Do not let your children rub mothballs or cleaners containing 1,4-di chlorobenzene on their skin. Because 1,4-di chlorobenzene may be found in the home as a pesticide and bathroom deodorizer and in mothballs, these items should be stored out of reach of young children to prevent accidental poisonings. Always store household chemicals in their original labeled containers never store household chemicals in containers children would find attractive to eat or drink from, such as old soda bottles. Keep your Poison Control Center s number by the phone. 

Only one report of human death attributed to 1,4-dichlorobenzene exposure has been located in the literature. A 60-year-old man and his wife died within months of each other due to acute yellow atrophy of the liver (also known as massive hepatic necrosis or fulminant hepatitis) (Cotter 1953). Their home had been "saturated" with 1,4-dichlorobenzene mothball vapor for a period of about 3-4 months, but no air measurements were available. Clinical symptoms included severe headache, diarrhea, numbness, clumsiness, slurred speech, weight loss (50 pounds in 3 months in the case of the husband), and jaundice. The wife died within a year of the initial exposure however, it was not clear if 1,4-dichlorobenzene was the primary cause of death. This case study did not address whether these individuals consumed excessive amounts of alcohol or had previous medical problems, such as a chronic liver infection. 

Hepatic Effects. Hepatic effects have been reported in humans following long-term exposure to 1,4-diehlorobenzene via inhalation. A 60-year-old man and his wife who were exposed to mothball vapor that "saturated" their home for 3-4 months both died of liver failure (acute liver atrophy) within a year of the initial exposure (Cotter 1953). Yellow atrophy and cirrhosis of the liver were reported in a 34-year-old woman who demonstrated 1,4-dichlorobenzene products in a department store and in a 52-year-old man who used 1,4-diehlorobenzene occupationally in a fur storage plant for about 2 years (Cotter 1953). Duration of exposure was not estimated for the 34-year-old woman, but was indicated in the report to be more than 1 year. No estimates of the 1,4-diehlorobenzene exposure levels (other than the use of the term saturated ) were provided in any of these reports, nor was it verified that... 

As discussed in Section 2.2.1, most human exposure to 1,4-dichlorobenzene results from inhalation of vapors due to home use of mothballs and deodorizer blocks that contain this chemical. Exposure resulting from all other sources, including proximity to hazardous waste sites, is considered to be low. 

In addition, several studies in animals have demonstrated that increased mortality can result from acute-, intermediate-, or chronic-duration oral exposure to 1,4-dichlorobenzene. Because 1,4-dichlorobenzene mothballs are used in many homes, they are often readily accessible in closets and storage areas. Therefore, there is a potential concern for the lethal effects of 1,4-dichlorobenzene, especially if accidentally consumed by young children. 

No reports of human death after ingesting 1,4-dichlorobenzene have been reported however, there is some concern that ingestion of 1,4-dichlorobenzene could result in human mortality based on two factors. First, 1,4-dichlorobenzene is used in many homes in the form of consumer products such as mothballs and toilet bowl deodorant blocks. Because of its availability in the form of mothballs and its pleasant taste, 1,4-dichlorobenzene can be accidentally ingested by young children. Secondly, a 19-year-old woman ingested 4-5 pellets of 1,4-dichlorobenzene daily for about 2.5 years (Frank and Cohen 1961) in another case a 21-year-old woman consumed one or two 1,4-dichlorobenzene toilet bowl deodorizer blocks per week throughout her pregnancy (Campbell and Davidson 1970). Thus, based on its... 

Physical Form. White crystalline solid with a characteristic mothball odor... 

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