- 1 Summary
- 2 Basic Safety Guidelines when Distilling
Will home-distilled alcohol make me go blind ? Not if you're careful. This pervasive question is due to moonshine lore, which abounds with myths of blindness, but few actual documented cases. The concern is due to the presence of methanol (wood alcohol), an optic nerve poison, which can be present in small amounts when fermenting grains or fruits high in pectin. This methanol comes off first from the still, so it is easily segregated and discarded. A simple rule of thumb for this is to throw away the first 50 mL (reflux still) you collect (per 20 L mash used), or 100-200 mL from a pot still.
There is no safe way to make methylated (denatured) spirits drinkable.
The other impurities, which form the tails (known as congeners or fusel oils) are quite a complex collection, but mostly just smell/taste bad rather than are actually unsafe towards you.
Basic Safety Guidelines when Distilling
Areas of concern with safety:
- Never leave a still that is running.
- Pay attention to the still - check it regularly (cooling water still flowing, no leaks, collecting nicely, all temperatures OK)
- Don't distill in a closed room. Try and keep some through-draught (eg both a window and door open). Distilling can produce some nasty smelling fumes.
- Be sober - its not a time to be making drunken mistakes.
- Do the math - don't boil the still dry
- Check your still with water-only the first time you use it, to make sure your condenser is up to the job. You don't want vapor coming out of the collection tube.
- A well designed still will not produce any significant pressure. If your still seems to be producing pressure shut it down immediately and figure out why.
- Make sure the still design is such that you can't pressurize the still - it should always be able to vent somehow to atmosphere. There shouldn't be valves such that you can fully close the column off
- Make sure the outlet tube is free flowing - not crimped or blocked in any way. Check this every time you use it.
- Lower end stills usually won't have pressure release valves or vacuum relief valves. This is a very good and inexpensive upgrade to increase safety.
- Cheap pressure cooker stills like that on Amazon are very dangerous. Their outlets are too small and can get clogged easily. This can lead to over pressure and an explosion.
- Alcohol burns nearly invisibly or with a weak blue flame. It is very difficult to detect. That's why it's so dangerous.
- Hot alcohol vapor will ignite with any ignition source.
- Room temp alcohol will burn at ~50% ABV or higher with an ignition source.
- Keep a fire extinguisher with you (and on your side of whatever is going to catch fire)
- Water is a good way to fight alcohol fires. Water will cool and dilute alcohol to put a fire out.
- Don't smoke - you don't want ignition sources around a liquid as flammable as gasoline
- If your still leaks (liquid or steam) shut it down immediately.
- If your condenser puffs vapor shut it down immediately. Your condenser is not cooling enough and is allowing highly flammable vapor to vent. Figure out if you're running too hot or else your condenser is not working properly.
- Collect the alcohol securely - don't put yourself in a position where its easy to knock over the collection vessel etc, or bump the tube out of it. This means having enough space to work in, well lit, tidy.
- Do the math and have enough jars or whatever to collect ~30% of the wash. Running out of jars is a really bad thing.
- If using electrical heating, have an GFCI/RCD on the line (a fancy circuit breaker)
- Water and electricity are a bad mix. If you get water/wash/spirit on electrical components shut them down and clean them before continuing.
- Make sure the electrical connections are not exposed, this could led to getting shocked.
- Keep close to the power switch or the cord in case there is an issue. You should be able to shut the power down quickly and easily if the need arises.
- If using direct flame heat have a CO monitor close by and ensure a good supply of fresh air.
- Ethanol is a very powerful solvent. It will react to most synthetics. You should use only recommended materials.
- Hi temp ethanol steam is even more so. The vapor path (lyne arm) in a still should only be made of copper or stainless steel. Aluminum will react ethanol.
- Seals for a still should only be made of PTFE or flour. The seals are exposed to the vapor and will leach chemicals if present. PTFE is non-reactive, flour is safe.
- For cold storage of low alcohol ABV (15% or less) PET, LDPE/MDPE/HDPE (Low/Medium/High density Polyethylene), stainless steel, or glass is fine.
- For cold storage of higher alcohol ABV (15% or more) only glass or stainless steel is ok.
- A discussion of plastics: Plastic codes
The greatest risk to anyone who drinks alcohol is the stock-standard pissed-as-a-newt high school student style of alcohol poisoning. It tends to come from our culture of binge drinking, rather than the more moderate consumption sometimes observed in Europe. Jack has the details ... The fatal dose of ethanol is 300-400 mL of pure ethanol (600-800 mL of 50% spirits), for the average adult if consumed in less than one hour.
Chronic users develop a tolerance to ethanol. Ethanol depresses the central nervous system irregularly in descending order from cortex to medulla, depending on the amount ingested. The range between a dose that produces anesthesia and one that impairs vital functions is small. Thus, an amount that produces stupor is dangerously close to a fatal dose. Effects are potentiated by concomitant ingestion of barbiturates and other depressant drugs.
- Intoxication levels (broadly) are found in this manner:
- Mild (Blood alc content 0.05%-0.15% - one fourth of the people at this level are clinically intoxicated) results in decreased inhibition, slight visual impairment, muscular uncoordination, and slowed reaction time.
- Moderate: (BAC: 0.15%-0.3% - 50 to 95% of the people at this level are clinically intoxicated)- results in definite visual impairment, sensory loss, muscular uncoordination, slurring of speech.
- Severe (BAC 0.3%-0.5% -fatalities begin to occur in this range)-marked muscular uncoordination, blurred vision, approaching stupor.
- Coma (BAC above 0.5% - death is common in this range)- Unconsciousness, slowed respiration, complete loss of sensations.
Treatment of acute poisoning begins with the removal of unabsorbed ethanol by gastric lavage with tap water or by emesis (induced vomiting). The airway must be kept clear- artificial respiration may be needed. Give 2grams of sodium bicarbonate in 250ml of tap water every 2 hours to maintain neutral or slightly alkaline urine, avoid administration of excess fluids. Avoid all depressant drugs. In the presence of hypoglycemia, give 5-10% glucose intravenously plus thiamine, 100mg intra-muscularly. Hemodialysis is needed if the blood ethanol level is above 5mg/ml. Survival for 24 hours is ordinarily followed by recovery.
I know most of the readers of this website are responsible enough to not need this information, but we just had another college student have a "21 drinks for 21 years" birthday party, and it killed him.
The next greatest risk to distillers is that of fire. You're producing a liquid which is on a par with gasoline with flammability, yet doing so around heating elements (or even gas flames).
Make sure that there is no way you can build up pressure inside your still - say by blocking the outlet piping (accidentally crimping it ?). Make sure your equipment is in good condition when you use it, that it's clean (don't want the packing material clogging up & blocking), and that there are no leaks. Don't bury the outlet tube under the surface of the liquid level in the collection jar, rather have it dripping into it openly. If using gas, keep the collection jar quite away from it. Don't set up your collection jars so that they are easily knocked over, and cap them when not in use. Keep your area well ventilated, and never leave the still unattended.
At all times keep a fire extinguisher close.
Will I go Blind? Methanol & Other Impurities
A big fear for many new distillers is that they are risking poisoning themselves with methanol, which can cause blindness. There is little basis for this fear however; if formed, it is only in small amounts, and can be easily discarded with the "heads" collected first during distillation.
A simple (but effective) rule of thumb for this is to throw away the first 50 mL you collect (per 20 L mash used) for a reflux still. If using a potstill, make it more like 100-200 mL. Do this, and you have removed all the hazardous foreshots, including the methanol. To get a really clean distinction between the foreshots and the rest of the alcohol, increase the reflux ratio to the point where you're taking off this first 50 mL at a very slow rate (eg 1 drop per second). This will give a very stable equilibrium within the column to allow all the methanol to collect at the top of the column and be in this first portion.
If you are doing a double or triple distillation with a pot still, don't worry about removing the heads & tails on the first pass. Wait for the second run, when they are more distinct & easier to separate. Once you have removed them, they are gone, so much less will need to be discarded from the subsequent runs, other than that dictated by taste, and any improved seperation that may result from running a more pure distillate through the still.
How dangerous are the various fusel oils ? I've got some of them listed below.
- The ones with toxicity data listed are ...
- Methanol : usual fatal dose 100-250 mL
- 1-Pentanol : LD50 (rat) 3030 mg/kg
- 3-Pentanol : LD50 (rat) 1870 mg/kg
Compare this to the amounts present in distilled spirits. The data in Wheeler & Willmotts "Spirits unlimited - a complete guide to *home distilling" gives : Home distilled spirit (untreated): methanol 0.0067%, ethanol 99.632%, fusels 0.361%
- Commercial vodka: methanol 0.013%, ethanol 99.507%, fusels 0.48%
- Poor quality home distilled spirit : methanol 0.0186%, ethanol 98.453%, and fusels 1.528%
If you're talking about untreated spirits as being dangerous, then to reach the LD50's that are published, you'd need to consume 149 L to be affected by the methanol, or for a 90kg bloke, about 58 L for the pentanol, from the "good" homemade stuff. That would be one hell of a session ! Even on their "poor quality" brew you'd need 11 L for the fusels. Stock standard pissed-as-a-newt high-school-student alcohol poisoning is the greater problem.
Now their "home distilled spirit" was at a time when their best design was only putting out roughly 75% pure ethanol. What's the story from like a Nixon-Stone or Euro doing 95%+ purity ?
Compare that to the levels of methanol etc that you get via other sources ...
Methanol is formed when fermenting beverages high in pectins - eg grapes and berries. Starting with a grain or sugar based wort, in a clean fermenter with a yeast culture from a well aerated source will result in small/none formed.
- Carl from Hambletonbard (makers of Alcotec yeasts) details ..
Methanol, you will typically get around 2 or 3 parts per million (or milligrams per liter if you prefer) of methanol produced during fermentation of a standard 6kg type Alcotec - this is extremely low even compared to commercial products. We don't have a great deal of data on methanol because whenever we have tested for it we have got extremely low results.
- Mike explains about the pectin ..
The methanol comes from the pectin, which mainly composed of methyl esters of galactose. When pectin breaks down, by enzymes introduced by microorganisms, or deliberately introduced, the methyl esters combine with water to produce methanol, so the aim should be to leave the pectin well alone if you can.
I think Jack would agree that what he means is that fermenting at a high temperature, or adding pectin enzyme, or trying for an abv higher than 12% all increase the risk of methanol being produced, so his advice about low temperature fermentation, adding no extra enzymes, and a target lower than 12% abv is all good stuff.
You are already being exposed to methanol from other sources. Some fruit juices are naturally high in methanol - for example apple juice can have 0.2-0.3% methanol, or if derived from pulp by enzymatic degradation, the levels can be 2 to 3 times higher.
- Johan found ..
In http://archive.food.gov.uk/maff/archive/food/infsheet/1993/no17/17orange.htm orange juice contains 10 to 50 times as much methanol as sugar mash.
The lethal dose of methanol is at least 100 ml that is equal to about 80000 mg or you need 27000 liters of mash at least to get that amount.
also from the web page: "Dietary surveys have shown that an extreme consumer of orange juice drinks slightly over 2 liters/day. The estimated maximum intake of methanol based on this consumption would be 455 mg for a 60 kg adult which is below the maximum advisory intake of 600 mg per day for a 60 kg adult, recommended by the Department of Health."
So if we stay under 600 mg per day we are safe, that's the same as 200 liters of mash per day or about 70 liters of 40% alcohol per day if you weight is 60 kg.
total amount of methanol in mash expressed in ml is about 0.1 ml = nothing.
- Jack comments ...
The Long Ashton Research Station did some studies that showed that ciders and apple juices clarified with pectic enzymes are higher in methanol due to the demethylation of juice pectins. The methanol content varied from 10 to 400 ppm in the test samples. I don't know which fruits are highest/lowest in pectin content, but apples are commonly considered the highest.
This is why all the old books on cider making refer to a condition called "apple palsey" - it's the massively painful hangover from the high methanol content. In order to prevent this (I'm sure distilling the pectin turns it into methanol) distillers must fully clarify any fruit wine before cooking it. Rather than use clarifiers, put the wine into 2 or 4 liter plastic jugs (only filled half full) and freeze them solid, then thaw them out, this will result in perfectly clear (and chill- stabilized) wine ready for distilling. After the thawing is complete or maybe as much as a week after, the wine will be crystal clear. Stephen Alexander reports that commercial spirits contain small levels of methanol. 'Food Chemistry' by Belitz & Grosch list an assay of about 50 different components of about 10 different distilled beverages. The US and Scotch whiskies had methanol levels around 0.2 to 0.3 %. Kevin Brown has scanned in some MeOH chromatograms from a column application guide published by Supelco of Bellefonte, PA. (a vendor for chromatography supplies). Check out http://amlc.uvi.edu/distill/meoh.html for details.
See also "Increasing Direct Marketing for Fruit Farmers by Connecting Producer to Producer through Research and Development of a Value-Added Product" at http://www.ams.usda.gov/tmd/FSMIP/FY2001/MO0341.pdf for quite a detailed report into the composition & quantities of impurities present etc in fruit brandies, and the factors affecting their production.
The Food and Drug Administration (FDA) advised ATF that 0.1 percent of methanol by volume in wine was a safe level. Any wine containing methanol in excess of this amount is deemed adulterated pursuant to the Federal Food, Drug and Cosmetic Act, 21 U.S.C. 34l(a)(2)(C) and 348.
From http://www.polishvodkas.com/fr_vodka-tech.htm - it reckons that a molasses wash won't have any methanol present!
"....Molasses spirit can also be rectified and then used to produce vodka. In some countries it is even preferred, since it contains no methyl alcohol at all. Crop-sourced spirit contains infinitesimal amounts of methyl alcohol which have no effect on health, but some people, victims of their own over concern, insist on molasses spirit. I should add that the presence of these tiny amounts of methyl alcohol have no effect whatever on the aroma of even unflavored vodka. It is simply undetectable. In neutral grain or potato spirit the methyl alcohol has practically disappeared....."
- "DBall" asks .. If Methanol is poison and is removed at the beginning of distillation... Question
- When/how is methanol removed from wine or beer?
- Brad answers ...
It's not tricky at all. Methanol is a by-product of fermentation; more methanol is produced in fruit fermentation than in grains. Brewers do not remove the methanol in beer and wine because methanol is not especially toxic at low concentrations. You are looking at between 0.4%-1% methanol in wines and brandies and smaller amounts in beers. Distillers remove almost all the methanol in most cases. Ever notice how vodka produces clean hangovers and wines (particularly reds) give you very nasty hangovers? Methanol. That, and dehydration!
Methanol is an especially nasty type of alcohol because the body tries to break it down the same way it metabolizes, or breaks down, ethanol, the type of alcohol in beer, wine and other drinks. Metabolizing ethanol produces chemicals less toxic to the body than alcohol. Unfortunately, if the same chemical action is performed on methanol the result is formic acid, lactic acid and formaldehyde.
Formaldehyde attacks nerve cells, especially the optic nerve and can damage the liver and kidneys. Formic acid and lactic acid also attack the kidneys and liver. Most people who have drunk methanol die of severe and sudden kidney and liver failure.
Chronic methanol drinking will cause optical damage. The stories of moonshine causing blindness comes from U.S. prohibition times where some bootleggers used to cut moonshine with methylated spirits to increase profit.
- Methanol Toxicity
Ups advises about methanol toxicity :
The fatal dose of methanol is 60 to 250 mL. Death depends on the size of the individual, their general health and stomach contents. The exposure limit is 200ppm. The highly lethal nature of methanol (compared to ethanol) has not been fully researched, but it is believed to be the result of the byproducts of metabolism, which turn methanol into formic acid and formaldehyde, and formaldehyde has been proven to have selective injurious effects on retal cells- this is the reason for it's ability to cause blindness.
Methanol is metabolized and excreted at a rate about one-fifth that of ethanol, and a single dose may take up to 4 days to leave the body (provided the drinker isn't already dead)
Symptoms fom acute poisoning of a moderate dose- Severe headache, dizziness, nausea and vomiting, and central nervous system depression. Vision may fail temporarily or permanently after 2-6 days. In higher doses the above occurs much faster and turn into rapid shallow breathing, blood pressure falling, dilation of pupils blurring of vision, cyanosis. More than 25% of those who reach this level, even in a hospital, still die.
Chronic poisoning tends to result in visual impairment as the first symptom. The only treatment from chronic poisoning is to halt all exposure.
Treating acute cases must be done within 2 hours of ingestion: give syrup of ipecac. Lavage thoroughly with 2-4L of tap water with sodium bicarbonate (20G/L) added. This is to treat acidosis of the blood)
- Antidote: Give ethanol, 50%, 1.5ml per kilo of body weight, orally, diluted to no more than a 5% solution, followed by 0.5-1ml/kg every 2 hours orally for 4 days. ethanol interferes with the absorption of methanol by the body and allows it to be excreted with less damaging effects. Also give up to 4 liters of water daily to maintain adequate urine output. Control delirium by giving 10mg valium slowly by injection in order to prevent respiratory depression.
- Prognosis:in acute methanol poisoning approx 50% do not recover. Visual impairment will show no improvement after 1 week.
Looking up medical and drug testing labs in the phone book will help you find someplace to send a sample of the stuff your making (say you found it in a friend's room and your worried about what he's drinking) to see how clean it is.
One real problem can be if you use lead based solder in building your still. A very bad practice that use to be prevalent was the use of old car radiators as the vapor condenser. THIS SHOULD NOT BE DONE. Car radiators are lead-soldered, and the lead will leach out and poison you. Any still construction should be welding, brazing, or silver soldering.
From "Moonshine & lead poisoning" : http://www.cdc.gov/mmwr/preview/mmwrhtml/00016616.htm May 01, 1992 / 41(17);294-295
Elevated Blood Lead Levels Associated with Illicitly Distilled Alcohol -- Alabama, 1990-1991
The use of automobile radiators containing lead-soldered parts in the illicit distillation of alcohol (i.e., "moonshine") is an important source of lead poisoning among persons in some rural Alabama counties.
From March 5 through October 26, 1991, eight persons were diagnosed with elevated blood lead levels (BLLs) at a local hospital and were reported to the notifiable disease surveillance system maintained by the Alabama Department of Public Health (ADPH). None of these patients had known histories of occupational or other potential sources of lead exposure, but all reported recent histories of moonshine ingestion. This report summarizes the results of an investigation of these cases conducted by the ADPH during December 1991.
A case-patient was defined as any person aged greater than or equal to 17 years who presented to the hospital from January 1, 1990, through December 31, 1991, and had a BLL greater than or equal to 15 ug/dL. Laboratory records of specimens submitted for blood lead determination, and medical records were reviewed at the hospital. In addition to the eight patients reported to the ADPH, review of laboratory records identified one patient with a BLL of 35 ug/dL during November 1990.
Patients ranged in age from 28 to 64 years (median: 33 years); five were female. Five patients resided in the county in which the hospital is located, and four lived in adjacent counties.
All nine patients had been evaluated for alcohol-related medical conditions at the hospital. Manifestations included generalized tonic-clonic seizures (six), microcytic anemia (five) (hematocrit mean: 32.1%), encephalopathy (two), upper extremity weakness (one), and abdominal colic (one). BLLs ranged from 16 ug/dL to 259 ug/dL (median: 67 ug/dL).
Seven patients required hospitalization for 48 hours or longer (range: 2-18 days). Three of these received chelation therapy; initial BLLs were 67, 228, and 259 ug/dL. One patient, whose BLL was 67 ug/dL, died during hospitalization from alcohol-withdrawal syndrome complicated by aspiration pneumonia.
Patients reported moonshine ingestion ranging from 0.2 L per day to 1.5 L per day. No specimens of moonshine consumed by the patients were available for analysis. However, the lead contents of specimens of moonshine confiscated from two radiator-containing stills in the county in 1991 were 7400 ug/L and 9700 ug/L, compared with nondetectable amounts (less than 1.0 ug/L) in municipal water from the county. Consumption of 0.5 L per day of moonshine containing 9700 ug/L lead would result in a steady state BLL of approximately 190 ug/dL. *
Reported by: T Dix, S Walker, MD, Crenshaw County Hospital, Luverne; D Cosby, Alabama Alcohol Beverage Control, Andalusia; CH Woernle, MD, State Epidemiologist, Alabama Dept of Public Health. Div of Field Epidemiology, Epidemiology Program Office; Lead Poisoning Prevention Br, Div of Environmental Hazards and Health Effects, National Center for Environmental Health and Injury Control, CDC.
Editorial Note: The findings in the ADPH investigation underscore the adverse health effects associated with consumption of moonshine. Specifically, this problem can result from the leaching of lead from solder used in radiators or the adjoining copper pipe during distillation; moonshine may contain up to 74 ug/L of lead (1).
In adults, manifestations of lead intoxication include gastrointestinal, hematopoietic, renal, reproductive, and neurologic findings (e.g., peripheral neuropathy and encephalopathy) (1-3). Because signs and symptoms of lead poisoning may be nonspecific, the relative contribution of lead and alcohol toxicity to illness in these patients could not be determined. However, overt signs and symptoms of neurotoxicity rarely occur in adults when BLLs are less than 40 ug/dL (1). Thus, the seizures observed in these patients with BLLs less than 40 ug/dL may have been related to alcohol withdrawal rather than lead toxicity.
This cluster of patients with elevated BLLs was detected through review of notifiable disease surveillance data. In Alabama, elevated BLLs (greater than or equal to 15 ug/dL) have been a notifiable condition since December 1990. In 1991, 612 persons aged greater than or equal to 17 years with BLLs greater than or equal to 15 ug/dL were reported to the ADPH notifiable disease registry. Of these, the two highest values (228 ug/dL and 259 ug/dL) were from patients in this cluster.
The nine patients identified in this cluster may under-represent the number of lead toxicity cases related to moonshine ingestion in the counties involved in this study and in others throughout Alabama. Although the number of illegal stills operating in Alabama is unknown, Alabama Alcohol Beverage Control destroyed 94 stills in 1991, including 50 stills in the county where the hospital is located and in two adjacent counties (D. Cosby, Alabama Alcohol Beverage Control, personal communication, 1992). Since a typical four-barrel still can produce 75-95 L of moonshine per week, a substantially higher number of persons may be at risk for lead toxicity from moonshine ingestion. Ongoing surveillance efforts are directed toward further characterizing risk factors for elevated BLLs and may assist in determining the scope of lead poisoning from moonshine ingestion among Alabama residents.
Because of the illegal source of the alcohol, patients may be reluctant to admit to moonshine ingestion. Therefore, clinicians, particularly in rural areas, should suspect moonshine ingestion when treating alcohol-abusing patients, both to detect and treat the adverse effects of lead poisoning and to direct alcohol-prevention efforts.
Agency for Toxic Substances and Disease Registry. Toxicologic profile for lead. Atlanta: US Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, 1992.
Baker EL, Landrigan PJ, Barbour AG, et al. Occupational lead poisoning in the United States: clinical and biochemical findings related to blood lead levels. Br J Ind Med 1979;36:314-22.
Goldman RH, Baker EL, Hannan M, Kamerow DB. Lead poisoning in automobile radiator mechanics. N Engl J Med 1987;317:214-8.
Assuming an equilibrium blood lead/dietary intake slope of 0.04 ug/dL per ug/day.
Why can't we get commercial methylated spirits and just distill it to make it safe to drink ?
Methylated spirits (a.k.a. denatured spirits) is ethanol or methanol with various chemicals added to make it non-potable (unsafe to drink). Some commercial distilleries sell their foreshots as metho after denaturing them with the pyridine and wood naptha group[s]; two of the most obnoxious, toxic/poisonous compounds in that family. The whole point of denaturing it is to add chemicals that can't be easily removed, then it can be sold without excise tax.
The additives chosen have vaporization properties almost identical to ethanol so can't be separated by distillation and/or chemical methods. The Australian/New Zealand Food Authority Act has chosen pyridine & wood naptha because they BOND in an ethanol/water solution most delightfully to the point that to separate this evil concoction you would need rising/falling film distillation equipment which worked under vacuum as well and then the result after one pass may only be marginal. This cost for this sort of equipment starts around 6 figures
Fusel Oil Composition
Thanks to Brad, heres a bit more detail on what has been found in the fusels, and can be present in your distilled product:
- 4195. Fusel Oil.
A by-product of carbohydrate fermentation to produce ethyl alc. The material varies widely in composition, depending on the fermentation raw material used, but contains chiefly isopentyl alcohol and 2-methyl-1-butanol as well as isobutyl alcohol(20%), n-propyl alcohol(3-5%), and small amounts of other alcohols, esters and aldehydes. Described as an oily liq with a disagreeable odor; 60% boils at 122-138°. Amyl alcohol (commercial) obtained by chemical treatment and refining of fusel oil contains about 85% isopentyl alcohol and 15% 2-methyl-1-butanol. Ref: Industrial Chemicals, W.L. Faith et al.
- 5816. Methanol.
Methyl alcohol; carbinol; wood spirit; wood alcohol. Flammable, poisonous, mobile liq. Slight alcoholic odor when pure; crude material may have a repulsive, pungent odor. Burns with a non-luminous, bluish flame. bp 64.7°. mp -97.8°. Caution: Poisoning may occur from ingestion, inhalation or percutaneous absorption. Acute Effects: Headache, fatigue, nausea, visual impairment or complete blindness (may be permanent), acidosis, convulsions, mydriasis, circulatory collapse, respiratory failure, death. Death from ingestion of less than 30ml has been reported. Usual fatal dose 100-250ml. Chronic: Visual impairment, cf.Patty's Industrial Hygiene and Toxicology vol. 2C, G.D.Clayton et al. pp 4528-4541.
The alcohols of interest in the same MERCK: (just the boiling points at atmospheric pressure, some basic characteristics and all the alternative names for each alcohol)
- 212. Alcohol, Anhydrous. Ethanol
ethyl alcohol. Clear, colorless, very mobile, flammable liquid; pleasant odor; burning taste. Absorbs water rapidly from air. bp 78.5°. mp -114.1°. Solidif below -130°.
- 4978. Isobutyl Alcohol.
2-methyl-1-propanol; isopropylcarbinol; 1-hydroxymethylpropane; fermentation butyl alcohol. Colorless, refractive liq; flammable; odor like that of amyl alcohol, but weaker. bp 108°. mp -108°.
- 5042. Isopentyl Alcohol.
3-methyl-1-butanol; isoamyl alcohol; isobutyl carbinol; primary isoamyl alcohol; fermentation amyl alcohol. Liquid; characteristic, disagreeable odor; pungent, repulsive taste. Vapors are poisonous! bp 132.0°. mp -117.2°. Caution: May be moderately irritating to mucous membranes. High concns may cause CNS depression, narcosis; lower concns, headache, dizziness.
- 5906. 2-Methyl-1-butanol.
Active amyl alcohol; dl-sec-butyl carbinol. One of the major components of fusel oil. Liquid, bp 128°.
dl-sec-Isoamyl alcohol; sec-isopentyl alcohol; isopropyl ethyl carbinol. Liquid, bp 113-114°. Fusel oil component.
- 211.Alcohol, 95%.
Binary azeotrope having a distillate composition of 95.57% ethyl alcohol (by wt) and bp 78.15°C. Also specified as containing 94.9% by vol or 92.3% by wt of ethyl alcohol at 15.56°C. See U.S.P. XVIII, 20, 1067(1970). d 0.816 at 15.56°C (60°F).
- 6985. 1-Pentanol.
Pentyl alcohol; n-amyl alcohol; n-butyl carbinol. Liquid, mild characteristic odor. bp 137.5°C. mp -79°C. Slightly soluble in water (2.7g/100ml at 22°C); misc with alcohol, ether. LD50 orally in rats: 3030mg/Kg, P.M.Jenner et al., Food Cosmet. Toxicol. 2, 327 (1964). Toxicity: Irritating to eyes, respiratory passages. Narcotic: E.Browning, Toxicity and Metabolism of Industrial Solvents (Elsevier, New York, 1965)pp 356-367.
- 6986. 2-Pentanol.
dl-sec-Amyl alcohol; methyl propyl carbinol. Liquid, characteristic odor. bp 119.3°C. Slightly soluble in water (16.6g/100ml at 20°C). Miscible with alcohol, ether. Caution: see 1-Pentanol.
- 6987. 3-Pentanol.
Diethyl carbinol. Liquid, characteristic odor. bp 115.6°C. Slightly soluble in water (5.5g/100g at 30°C); sol in alcohol, ether. LD50 orally in rats: 1870mg/Kg, Smyth et al., Arch. Ind. Hyg. Occup. Med. 10, 61 (1954). Caution: see 1-Pentanol.
- Brad also commented :
As you can probably see from these brief descriptions, methanol appears to be one of the most toxic of all. In fact the other alcohols by and large appear to have much the same effct as ethanol when consumed (with much greater activity/toxicity), except methanol which has some toxic metabolite (formaldehyde) which is somehow toxic to the optical nerves of the eye. Ethanol administration is actually used to slow down the metabolism of methanol when it's accidentally consumed! Note the Merck note about Chronic effect (long-term use) of methanol being visual impairment; does this occur to heavy drinkers?!?