extend similar protections to students. So when your teacher orders
chemicals for the lab, each chemical will come shipped with an SDS,
either in written or electronic form. Having an SDS on hand for each
chemical you use in the lab is not just a good idea—it’s the law.
The SDS for any chemical is written by the supplier or manufacturer of that chemical. There is a great deal of motivation for these
companies to be thorough and accurate, as any incomplete or false
information could lead to serious harm by the user, not to mention
a lawsuit. But an SDS does not address the possible hazards that could occur as a
chemical reaction moves forward
and the constituents and concentrations of the chemicals involved
Let’s look at an example of an SDS
for methanol and see if it contains
information that could have helped to
prevent the tragedies described above.
Section 2 of the SDS is labeled
“Hazards Identification.” A typical listing for methanol under
this section may read as shown below (see “Highlights from
‘Section 2: Hazards Identification’ ”).
By reading the information contained in the SDS, the highly flammable
nature of methanol is revealed. It is so flammable that there is a direct
warning to avoid open flames and even sparks.
Although the label says that both the liquid and vapor are flammable,
the liquid itself does not actually burn. When a liquid is ignited, it is the
vapors on top of the liquid that burn. For a liquid to be considered flammable, it needs to evaporate quickly so that enough vapors can form
above the surface of the liquid to support combustion. It is these vapors
that will ignite, if enough heat is applied.
Many accidents involving
methanol occur because it is
poured onto an open flame.
The same precaution against
pouring any substance onto
an open flame should be followed.
Even though most people
should know better than
to pour a flammable liquid
onto an open flame, sometimes even trained professionals make this mistake
with methanol, with disastrous consequences.
Read through section
5 of the SDS (see
‘Section 5: Fire-Fighting Measures’ ” on the
right) to see if you can figure out why this mistake
Because methanol burns with a clear, clean flame, it is often difficult to
see this flame in the daytime. As stated in the SDS, the flame may appear
invisible during the day. If you are performing a demonstration where a
methanol flame is produced and then the flame dies down, you might be
tempted to add more methanol, thinking that the fire has gone out. This
could be a tragic mistake.
Flash point and autoignition
Methanol does not have to be poured directly onto a flame
to produce unintended results. On September 3, 2014, a
demonstrator at a science museum in Reno, Nev., attempted
to conduct a flame tornado demonstration on a rotating plat-
form that makes a vortex composed of flames. He poured
some additional methanol onto cotton balls in a dish after
the flames had apparently gone out, but the cotton balls
were still smoldering and instantly re-ignited when the
methanol was added. The flame traveled up into the
bottle (as described in the SDS), spraying the flaming
liquid into the audience. Thirteen people were injured,
Highlights from "Section 2:
Ü Highly flammable liquid and vapor
Ü Keep away from heat, sparks, open
flames, hot surfaces. - No smoking
Ü Toxic if swallowed, in contact with
skin or if inhaled
Ü Causes damage to organs
Ü Use only non-sparking tools
Ü Take precautionary measures
against static discharge
Highlights from "Section 5: Fire-Fighting Measures"
ÜHighly flammable liquid and vapor ÜSealed containers exposed to excessive heat may explode ÜVapors may travel back to ignition source
ÜFlame may be invisible during the day ÜUse dry chemical, CO2, or foam to extinguish
ÜAvoid using water to extinguish— water may not cool the fire to a tem- perature below methanol’s flash point. Ü Water will cause fire to spread if not contained.
Ü Water and methanol mixtures still flammable at concentrations above 20% methanol
1. Gases under pressure____
4. Acute toxicity (severe)______
7. Environmental toxicity________
9. Carcinogen, reproductive or
organ toxicity, or respiratory
(Answers on p. 7)