Ethyl toxicity

Health and Safety Factors. The following toxicities have been reported for cyanoacetic acid oral LD q (rat) 1500 mg/kg subcutaneous LD q (rabbit), 1900 mg/kg and subcutaneous LD q (frog) 1300 mg/kg (29). Eor ethyl cyanoacetate the following toxicities have been reported interperitoneal LD q (mice), 750 mg/kg subcutaneous LD q (rabbits), 1500 mg/kg and subcutaneous LD q (frogs), 4000 mg/kg. 

Table 4 lists a variety of aLkoxypropionaldehydes and certain of thek properties (67). Alcohols up to -butyl have been added to acroleki ki this fashion. Methyl, ethyl, and aHyl alcohols react with ease, while the addition of hexyl or octyl alcohol proceeds ki low yields. Although the aLkoxypropionaldehydes have found only limited kidustrial utiUty, it is anticipated that they will find use as replacements for more toxic solvents. Furthermore, the aLkoxypropionaldehydes may readily be reduced to the corresponding alkoxypropanols, which may also have deskable properties as solvents. 

The Brominated Flame Retardants Industry Panel (BFRIP) was formed ia 1985 within the Flame Retardant Chemicals Association (FRCA) to address such concerns about the use of decabromodiphenyl oxide. Siace 1990 the BFRIP has operated as a Chemical Self-Funded Technical Advocacy and Research (CHEMSTAR) panel within the Chemical Manufacturers Association (CMA) (64). As of 1993, members of BFRIP are Ak2o, Amerihaas (Dead Sea Bromine Group), Ethyl Corp., and Great Lakes Chemical. Siace its formation, BFRIP has presented updates to iadustry on a regular basis (65,66), and has pubhshed a summary of the available toxicity information on four of the largest volume brominated flame retardants (67,68) tetrabromo bisphenol A, pentabromodiphenyl oxide, octabromodiphenyl oxide, and decabromodiphenyl oxide. This information supplements that summarized ia Table 11. 

Beryllium Hydride. BeryUium hydride [13597-97-2] is an amorphous, colorless, highly toxic polymeric soHd (H = 18.3%) that is stable to water but hydroly2ed by acid (8). It is insoluble in organic solvents but reacts with tertiary amines at 160°C to form stable adducts, eg, (R3N-BeH2 )2 (9). It is prepared by continuous thermal decomposition of a di-/-butylberylhum-ethyl ether complex in a boiling hydrocarbon (10). 

Health and Safety Factors. MEK is slightly more toxic than acetone, but is not considered highly toxic, and nor does it exhibit cumulative toxicological properties. The OSHA time weighted average iu air is 200 ppm other measured toxicity values are shown iu Table 3. Methyl ethyl ketone is highly flammable. 

Naphthol is mainly used in the manufacture of the insecticide carbaryl (59), l-naphthyl A/-methyicarbamate/ iJ-2j5 - (Sevin) (22), which is produced by the reaction of 1-naphthol with methyl isocyanate. Methyl isocyanate is usually prepared by treating methylamine with phosgene. Methyl isocyanate is a very toxic Hquid, boiling at 38°C, and should not be stored for long periods of time (Bhopal accident, India). India has developed a process for the preparation of aryl esters of A/-alkyl carbamic acids. Thus l-naphthyl methylcarbamate is prepared by refluxing 1-naphthol with ethyl methylcarbamate and POCl in toluene (60). In 1992, carbaryl production totaled > 11.4 x 10 t(35). Rhc ne-Poulenc, at its Institute, W. Va., facihty is the only carbaryl producer in United States. 

Methyl Ethyl Ketone Peroxide in Dimethyl Phthalate (4TT3)), National Toxicology Program, Toxicity Report Series Number 18, NIH Pubhcation 93-3341, United States Department of Health and Human Services, Washington D.C., Eeb. 1993. 

Mesitylene. One of the principal derivatives of mesitylene is the stericaHy hindered phenol of the stmcture shown in Eigure 4. Its trade name is Ethanox 330 and it is produced by Albemarle Corporation (formerly Ethyl Corporation) (31). Ethanox 330 is an important noncoloring antioxidant and thermal stabiHzer for plastics, adhesives, mbber, and waxes (qv) (32,33) (see Antioxidants). The oral toxicity of Antioxidant 330 is extremely low (oral LD q in rats >15 g/kg) since its large size, C H gO, effectively eliminates absorption from the gastrointestinal tract. 

Thiuram Sulfides. These compounds, (8) and (9), are an important class of accelerator. Thiurams are produced by the oxidation of sodium dithiocarbamates. The di- and polysulfides can donate one or more atoms of sulfur from their molecular stmcture for vulcanization. The use of these compounds at relatively high levels with litde or no elemental sulfur provides articles with improved heat resistance. The short-chain (methyl and ethyl) thiurams and dithiocarbamates ate priced 2/kg. Producers have introduced ultra-accelerators based on longer-chain and branched-chain amines that are less volatile and less toxic. This development is also motivated by a desire to rninirnize airborne nitrosamines. 

International Specialty Products (ISP) suppHes ethyl, isopropyl, and -butyl half-esters of PMVEMA as 50% solutions in ethanol or 2-propanol. Typical properties are shown in Table 8. These half-esters do not dissolve in water but are soluble in dilute aqueous alkaU and in aqueous alcohoHc amine solutions. The main appHcation for the half-esters is in hairsprays where they combine excellent hair-holding properties at high humidity without making the hair stiff or harsh. These half-esters are easily removed during shampooing, have a very low order of toxicity, and form tack-free films that exhibit good gloss, luster, and sheen (see Hair preparations). 

The most important hazard ia the manufacturiag of xanthates is the use of carbon disulfide (qv) because of its low flash poiat, ignition temperature, and its toxicity. A report on the manufacture of sodium ethyl xanthate at Keimecott Nevada Mines Division discusses the various safety problems and the design of a faciUty (81). A plant layout and a description of the reagent preparations are also given. 

Propionates and higher aliphatic esters generally become less toxic as the si2e of the alkyl carboxylate increases. As an example, the LD q (rat, oral) for ethyl nonanoate [123-29-5] is greater than 43 g/kg, and the LD q (rat, oral) for ethyl heptanoate [106-30-9] is 34.6 g/kg. 

Ethyl acetate (exempt solvent) is much less toxic than MEK. 

Some authorities question whether dmnkeimess can result from the inhalation of ethyl alcohol vapors. Experience has demonstrated that in any event such intoxication is indeed rare (281). There is no concrete evidence that the inhalation of ethyl alcohol vapor will cause cirrhosis. Liver function is definitely impaired during alcohol intoxication (282), making the subject more susceptible to the toxic effects of chlorinated hydrocarbons. 

Toxicology. The toxicity of ethyl ether is low and its greatest hazards in industry are fire and explosion. The vapor is absorbed almost instandy from the lungs and very prompdy from the intestinal tract. It undergoes no chemical change in the body. Prevention and control of health hazards associated with the handling of ethyl ether depend primarily on prevention of exposure to toxic atmospheric concentrations and scmpulous precautions to prevent explosion and fire. 

Ethyl dibunate [5560-69-0] (59), which is sold ia Canada, is the ethyl ester of 3,6-(/ f2 -butyl)-l-naphthalenesulfonic acid. It is stmcturaHy unrelated to most of the classical antitussives and is a selective central inhibitor of the cough reflex. Also significant is its low toxicity. The oral LD q is greater than 5000 mg/kg in the rat. The clinical and pharmacological profile of this compound has been reviewed (89). 

Furan, 3-acetoxy-2,4,5-triphenyl-synthesis, 4, 659 Furan, 2-acetyl-isopropylation, 4, 607 rotamers, 4, 544 synthesis, 4, 665 toxicity, 1, 136 Furan, 3-acetyl-bromination, 4, 604 Furan, 3-acetyI-2-amino-reactions, 4, 74 Furan, 2-acetyl-3,5-dimethyl-synthesis, 4, 691 Furan, 2-acetyl-5-ethyl-synthesis, 4, 691 Furan, 2-acetyl-3-hydroxy-synthesis, 4, 649... 

V-Allylthiourea (thiosinamine) [109-57-9] M 116.2, m 70-73 , 78 . Recrystd from H2O. Soluble in 30 parts of cold H2O, soluble in EtOH but insoluble in "CeHg. Also recrystd from acetone, EtOH or ethyl acetate, after decolorising with charcoal. The white crystals have a bitter taste with a slight garlic odour and are TOXIC. [Anal Chem 21 421 7949.]... 

Benzoyl suinde [644-32-6] M 174.4, m 131.2-132.3 . About 300mL of solvent was blown off from a filtered soln of benzoyl disulfide (25g) in acetone (350mL). The remaining acetone was decanted from the solid which was recrystd first from 300mL of 1 1 (v/v) EtOH/ethyl acetate, then from 300mL of EtOH, and finally from 240mL of 1 1 (v/v) EtOH/ethyl acetate. Yield about 40% [Pryor and Pickering J Am Chem Soc 84 2705 7962]. Handle in a fume cupboard because o/TOXICITY and obnoxious odour. 

Ethyl chloroformate [541-41-3] M 108.5, m -81 , b 94-95 , d 1.135, n 1.3974. Washed several times with water, redistd using an efficient fractionating column at atmospheric pressure and a CaCl2 guard tube to keep free from moisture [Hamilton and Sly J Am Chem Soc 47 435 1 925 Saunders, Slocombe and Hardy, J Am Chem SocT3 3796 1951]. LACHRYMATORY AND TOXIC. 

Ethyl trifluoromethanesulfonate [425-75-2] M 178.1, b 115 /atm, 118-120 /atm, d 1.378, Hp 1.336. The ester reacts slowly with H2O and aqueous alkali. If its IR has no OH bands (-3000 cm" ) then purify by redistillation. If OH bands are present then dilute with dry Et20 and shake (carefully) with aqueous NaHC03 until effervescence ceases, then wash with H2O and dry (MgSOa), filter, evaporate and distil the residue under slight vacuum then at atmospheric pressure in a N2 atmosphere. IT IS A POWERFUL ALKYLATING AGENT, AND THE FUMES ARE VERY TOXIC - CARRY ALL OPERATIONS IN AN EFFICIENT FUME CUPBOARD. [Gramstad and Hazeldine J Chem Soc 173 7956 Howells and McCown Chem Rev 77 69 1977.]... 

Solvents acetone, methyl ethyl ketone (MEK), toluene, xylene, glycol, ethers, alcohol defats and dries skin some may be absorbed may carry other components through skin high volatility, exposure possible irritation central nervous system depression (e.g. dizziness, loss of coordination) low to high toxicity, longterm effects... 

Polymeric ethyl cyanoacrylate exhibits very low toxicity properties. In tests with laboratory rats, oral administration of 6400 mg/kg of the polymer failed to harm the test animals. Some skin irritation did occur in tests on guinea pigs, but skin sensitization or absorption through the skin was not observed [45]. 

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