Strong Acid Processes

Isopropyl alcohol manufacture (strong acid process)... 

Manufacturing qualifiers. Two of the entries to the section 313 chemical list contain a qualifier relating to manufacture. For isopropyl alcohol, the qualifier is "manufacturing-strong acid process. For saccharin, the qualifier simply is "manufacturing." For isopropyl alcohol, the qualifier means that only facilities which manufacture isopropyl alcohol by the strong acid process are required to report. In the case of saccharin, only manufacturers of the chemical are subject to the reporting requirements. A facility that processes or otherwise uses either chemical would not be required to report for those chemicals. In both cases, supplier notification does not apply because only manufacturers, not users, of the toxic chemical must report. 

An increased incidence of cancer of the paranasal sinuses was observed in workers at factories where isopropyl alcohol was manufactured by the strong-acid process (lARC, 1987). The risk for laryngeal cancer may also have been elevated in these workers. It is unclear whether the cancer risk was due to the presence of diisopropyl sulfate, which is an intermediate in the process, to isopropyl oils, which are formed as by-products, or to other factors, such as sulfuric acid. 

Diethyl sulfate is manufactured from ethylene and sulfuric acid. It is used principally as an intermediate (ethylating agent) in the manufacture of dyes, pigments and textile chemicals, and as a finishing agent in textile production. It is an intennediate in the indirect hydration (strong acid) process for the preparation of synthetic ethanol from ethylene. No data were available on levels of occupational exposure to diethyl sulfate (lARC, 1992a). 

An early cohort study of isopropanol manufacture using the strong-acid process at a... 

Isopropyl oils, formed during the manufacture of isopropanol by both the strong-acid and weak-acid processes, were tested inadequately in mice by inhalation, skin application and subcutaneous administration. Isopropyl oils formed during the strong-acid process were also tested inadequately in dogs by inhalation and instillation into the sinuses (lARC, 1977, 1987). 

One of the most important facets of the mixer con arison was the effect of the mixer type on alkylate quality. As mentioned previously, since acid composition does have a profound effect on quality it is necessary to compare mixing effects at constant acid composition. For this study, the acid con ionent which seemed to play the key role in this composition/quality effect is the acid soluble oil. This component, which is characteristic of strong acid processes, is a complex mixture in which cyclic conjunct polymers predominate ( ). Since alkylate quality does vary markedly with acid soluble oil content, many theories on its role in quality enhancement have been proposed such as a hydride transfer agent, surfactant, or agent to increase isobutane solubility. 

Isopropyl Alcohol (Mfg-Strong Acid Process) A235 Precursor 129... 

This strong acid process is straightforward but for a key factor — the cost of handling and recovering the acid. Gregor and Jefferies point out that advances in membrane technology may offer a solution to this problem (. ... 

Strong acid process in the manufacture of isopropyl alcohol. 

All industrial processes which are listed in aimex I of the carcinogens and mutagens directive 90/679/EEC, now 2004/37/EC (e.g., manufacture of auramine, work involving polycyclic aromatic hydrocarbons, roasting and electro-refining of cupro-nickel mattes, strong acid process for the manufacture of isopropyl alcohol, work involving exposure to hardwood dusts, see also Section 6.4). 

VOC = volatile organic compound HAP = Hazardous air pollutant Sec 313 of the Emergency Right-to-know Act (EPCRA), also known as Title 111 of the Superfund Amendments and Reauthorization Act of 1986 (40 CFR Part 372). Use of strong acid process, no supplier notification. Ligroine (light naphtha), VM P naphtha, Stoddard solvent, and certain paint thinners are also commonly referred to as mineral spirits. These distillation fractions contain less than 10 % by mass HAPs (see Table 14.26.4). 

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