Doug White (gwhite@ll.mit.edu) posted this on 11/16/94 regarding safety of some common solvents:
HEALTH HAZARDS OF COMMON CHEMICAL CLEANING SOLVENTS
People in several different newsgroups I subscribe to use chemical solvents for various projects. A while back in rec.bicycles, there was a discussion of the health hazards of using these solvents. A friend of mine is in the laboratory safety business, and ran off copies of the 'Material Safety Data Sheets' (MSDS) for many of the common solvents. It's a bit tricky to cover everything, because some are known by several different names, and MSDS's from different sources don't list things in a consistent manner. I've attempted to consolidate this information into something that covers the critical differences between the solvents, and that is easy to understand for people like me who aren't safety experts or chemists.
I've listed these (roughly) in decreasing order of 'nastiness'. It's difficult to do a precise ranking, because some solvents are greater risks depending on whether you touch it, breath it, drink it, or set it on fire. If there is anything you like to use that you don't see here, just call the manufacturer and ask for the MSDS on the product. They are required by law to send you one. There are several key things I would watch out for:
Because all of these solvents dissolve grease and oil, at a minimum, they will leach the oils out of your skin. With prolonged exposure, this can cause irritation and dermatitis. Your senses are a good warning system. If a mere whiff of something makes your eyes water and your head spin, it's probably not too good for you. Whatever you like to use, do so with adequate ventilation, gloves, eye protection, and away from any source of combustion.
Nitrobenzine: (AKA Essence of Mirbane, Mirbane oil) I've included this because it used to be used in some gun cleaning solvents. It was removed because of health risks. Nasty stuff.
Very toxic by inhalation, skin contact, or ingestion
Irritating to eyes, respiratory system and skin
Danger of cumulative effects, causes nervous system disorders
Combustible, Flashpoint = 190F, 87C
Readily absorbed through skin, do not breath vapor.
Time Weighted Average exposure limit 1 part per million (5 mg/M*3)
Kerosene: (AKA Coal Oil, Range Oil) Easy to obtain. This was my father's favorite all-round solvent. Works well on bicycles chains.
Toxic by inhalation or ingestion
Irritating to eyes, respiratory system and skin
Attacks central nervous system
Combustible, Flashpoint = 100F, 38C
Time Weighted Average exposure limit 14 parts per million (100 mg/M*3)
Lacquer Thinner: This is a mixture of a variety of chemicals, and will vary with manufacturer. Some of the components are pretty nasty, but information on the mixture is not very complete. The brand I have a data sheet on contains: Isopropanol, n Butyl Acetate, Methanol, Acetone, VM&P Naptha, Toluene, and Hexane. This is a particularly effective solvent, and works very well removing hardened grease and grime from old machine tools.
Toxic by inhalation, minimal toxicity by ingestion
Irritating to eyes, respiratory system and skin
Attacks central nervous system
Flammable, Flashpoint = -10F, -23C
The Worst component (Hexane) has a Time Weighted Average exposure limit
of 50 parts per million, but it's percentage in the mixture is unknown
Naptha: (AKA Lighter Fluid, Petroleum Ether) This is one of my favorite cleaning solvents, because it doesn't attack most plastics or paint. It's great for removing adhesive from tape and labels. Although it is listed as a skin irritant, it isn't toxic if you spill some on your hands.
Toxic by inhalation or ingestion
Irritating to eyes, respiratory system and skin
Attacks central nervous system
Highly Flammable, Flashpoint = -57F, -49C
Time Weighted Average exposure limit 100 parts per million (400 mg/M*3)
Paint Thinner: (AKA Mineral Spirits, Petroleum Naptha) A common solvent, readily available at most hardware stores. It is considered non- irritating to eyes.
Toxic by inhalation or ingestion
Irritating to respiratory system, slightly irritating to skin
Attacks central nervous system
Combustible, Flashpoint = 111F, 44C
Time Weighted Average exposure limit 100 parts per million (400 mg/M*3)
Turpentine: (AKA Spirit or Oil of Turpentine) I never use this anymore, but it was THE standard paint brush cleaner before latex paints came out.
Toxic by inhalation or ingestion
Irritating to eyes, respiratory system and skin
Can penetrate skin to produce systemic effects. Can cause eye damage
Prolonged exposure can cause allergenic sensitization.
Combustible to Flammable, Flashpoint = 90-115F, 32-46C
Time Weighted Average exposure limit 100 parts per million (560 mg/M*3)
Acetone: (AKA Methyl Ketone, Propanone, Pyroacetic Ether) The one unique application I know of for acetone is that it dissolves cyanoacrylate glues (SuperGlue). It will attack many plastics.
Toxic by inhalation or ingestion
Irritating to respiratory system and skin
Risk of serious damage to eyes
Attacks liver and kidneys
Flammable, Flashpoint = 1F, -17C
Time Weighted Average exposure limit 200-1000 parts per million
(470-2400 mg/M*3) (Varies substantially from country to country)
Denatured Alcohol: (Denatured Ethanol) This is ethyl alcohol with just enough 'denaturant' to make you violently ill if you try to make a cocktail out of it. Denaturants vary, but the most common one is a few percent methyl alcohol (methanol). I couldn't find a MSDS on the 'denatured' version, so the info below is from the ethanol MSDS. The only major difference should be in toxicity by ingestion, which is the whole point of the denaturant. Ethanol is a fairly mild solvent, and may require more patience and elbow grease than others. On the other hand, it's pretty safe. Water dissolves in it, so you can use it to dry off delicate items that have gotten wet, or have been washed in water first. Ethanol will cleanly remove even the most fossilized protective paper from acrylic plastic (Plexiglass), if you let it soak overnight in a plastic bag.
Somewhat toxic by ingestion (mostly because of denaturant)
Excessive exposure to vapors can cause eye and respiratory irritation
Flammable, Flashpoint = 50-55F, 10-13C
Time Weighted Average exposure limit 1000 parts per million (1900 mg/M*3)
Orange Oil: (AKA OptiClear & lots of other tradenames) This is listed as a 'food oil distillate'. It's a volatile liquid extracted from orange peels, and smells like oranges. The manufacture of 'OptiClear' recommends it as a replacement for 'toluene, xylene, or chlorinated hydrocarbons such as TCE' (Trichloroethylene). It is biodegradable. This is the only type of solvent that is listed as GRAS (Generally Regarded as Safe).
Not considered toxic
Can cause skin irritation
Combustible, Flashpoint = 140F, 60C
No exposure limit
Before everyone floods me with email asking where you can get this stuff, 'OptiClear' is an optical grade solvent used at the lab where I work. It's probably a bit more refined (and expensive) than what most people need. The price info I have is very old, but lists a case of four 1 gallon jugs for $86. It's manufactured by:
National Diagnostics, Inc.
1013-1017 Kennedy Blvd.
Manville, NJ 08835
(201) 722-8600
I have seen ads for other brands of orange based solvents, but haven't ever bought any. My local hardware stores don't seem to carry it. If someone has a good source, I'd love to hear about it.