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Ethers

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Ethers are organic compounds in which oxygen serves as a link between two organic radicals. Most of the ethers of industrial importance are liquids, although methyl ether is a gas and a number of ethers, for example the cellulose ethers, are solids.

Hazards

The lower-molecular-weight ethers (methyl, diethyl, isopropyl, vinyl and vinyl isopropyl) are highly flammable, with flashpoints below normal room temperatures. Accordingly, measures should be taken to avoid release of vapours into areas where means of ignition may exist. All sources of ignition should be eliminated in areas where appreciable concentrations of ether vapour may be present in normal operations, as in drying ovens, or where there may be accidental release of the ether either as a vapour or as a liquid. Further control measures should be observed.

On prolonged storage in the presence of air or in sunlight, ethers are subject to peroxide formation that involves a possible explosion hazard. In laboratories, amber glass bottles provide protection, except from ultraviolet radiation or direct sunlight. Inhibitors such as copper mesh or a small amount of reducing agent may not be wholly effective. If a dry ether is not required, 10% of the ether volume of water may be added. Agitation with 5% aqueous ferrous sulphate removes peroxides. The primary toxicological characteristics of the non-substituted ethers is their narcotic action, which causes them to produce loss of consciousness on appreciable exposure; and, as good fat solvents, they cause dermatitis on repeated or prolonged skin contact. Enclosure and ventilation are to be employed to avoid excessive exposure. Barrier creams and impervious gloves assist in preventing skin irritation. In the event of loss of consciousness, the person should be removed from the contaminated atmosphere and given artifical respiration and oxygen.

The principal physiological effect of the unhalogenated ethers shown in the accompanying tables is anaesthesia. At high exposures, such as repeated exposures in excess of 400 ppm to ethyl ether, nasal irritation, loss of appetite, headache, dizziness and excitation, followed by sleepiness may result. Repeated contact with the skin may cause it to become dry and cracked. Following long-term exposures, it has been reported that mental disorders may occur.

Halogenated ethers

In contrast to the unhalogenated ethers, the halogenated ethers represent serious industrial hazards. They share the chemical property of being aklylating agents—that is, they can chemically bind alkyl groups, such as ethyl- and methyl- groups to available electron donor sites (e.g., -NH2 in genetic material and haemoglobin). Such alklyation is believed to be intimately related to the induction of cancer and is discussed more fully elsewhere in this Encyclopaedia.

Bis(chloromethyl) ether (BCME) is a known human carcinogen (Group 1 classification by the International Agency for Research on Cancer (IARC)). It is also an extremely irritating substance. The carcinogenic effects of BCME have been observed in workers exposed to the substance for a relatively short period of time. This reduced latency period is probably related to the potency of the agent.

Chloromethyl methyl ether (CMME) is also a known human carcinogen which is intensely irritating as well. Exposure to the vapours of CMME even at levels of 100 ppm can be life threatening. Workers exposed to such levels have experienced serious respiratory effects, including pulmonary oedema.

Unless there is evidence to the contrary, it is prudent to treat all halogenated ethers prudently and to consider all alkylating agents potential carcinogens unless there is evidence to the contrary. The glycidyl ethers are considered in the family entitled “Epoxy compounds” .

Ethers tables

Table 1 - Chemical information.

Table 2 - Health hazards.

Table 3 - Physical and chemical hazards.

Table 4 - Physical and chemical properties.

Halogenated ethers tables

Table 1 - Chemical information.

Table 2 - Health hazards.

Table 3 - Physical and chemical hazards.

Table 4 - Physical and chemical properties.

 

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Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides