Nitromethane Color Question

[Bruce Reynolds]

Guys,

We purchased some nitro from a local source to mix up some home-brew.  We didn't pay much attention to it until we got home and noticed that the color was more of a light golden brown verses the more yellowish-sort-of-lemonade color we remembered from back in the day of rolling our own fuels.

Does anyone have any knowledge on whether the color indicates a problem with the nitro, or whether there are different grades, or should we just shut up and mix it? 

Thanks for any info.

[Tim Wescott]

Wikipedia, which must be accurate because anyone can edit an article, lists nitromethane as a colorless liquid (see http://en.wikipedia.org/wiki/Nitromethane).

My suspicion is that the color in your nitro was most likely specified by a marketing guy, not an engineer.

[Steve Fitton]

Pure nitromethane is indeed a colourless liquid.  Back in my lab days, we had to do some tests on nitro for a drag racing organization, at the time comparing relative purities of US made vs Chinese made nitro.  The US made was colorless and typically exceeded 99% purity, the Chinese nitro was amber in color and typically around 96% purity, with water being detectable as well as a host of organic compounds.

[Robert Schroeder]

Yeah, and now the only source is chicom.

[Mike Lauerman]

Our current administration is making every effort to keep dangerous chemicals out of our incompetent hands. Thank God for a wizard for a president.

[Howard Rush]

Yellow dye in nitro is an indicator that turns blue if it's contaminated with something that could make it dangerous.  If it's contaminated by an amine or a base, the nitro forms an azide (as I remember), becomes shock sensitive, and could blow up.   Most nitro I've found has the dye; some doesn't.   In a previous nitro shortage-- maybe 20 years ago-- I got some bad Chinese nitro.  It turned brown and dissolved metal.  Chinese nitro I've gotten lately has been just fine.  I got the last batch from Mark Smith in Arizona.  Density was spot on for pure nitro.   

[Greg McCoy]

Confirming Howard's info, the MSDS calls it a colorless liquid, made unstable by amine and acid contamination.

 
Safety data for nitromethane

 
Glossary of terms on this data sheet.
The information on this web page is provided to help you to work safely, but it is intended to be an overview of hazards, not a replacement for a full Material Safety Data Sheet (MSDS). MSDS forms can be downloaded from the web sites of many chemical suppliers.

General

Synonyms: nitrocarbol
Use: detonating agent, fuel, solvent, gasoline additive
Molecular formula: CH3NO2
CAS No: 75-52-5
EC No: 200-876-6
Annex I Index No: 609-036-00-7
Physical data

Appearance: Colourless oily liquid
Melting point: -29 C
Boiling point: 100 - 102 C
Vapour density: 2.1
Vapour pressure: 27.8 mm Hg at 20 C
Specific gravity: 1.136
Flash point: 36 C
Explosion limits: lower 7.3% upper n/a
Autoignition temperature:
Critical temperature: 315 C
Critical pressure 62.3 atm
Water solubility: substantial
Stability

May detonate if sensitized by amines, alkalies, strong acids, high temperatures or adiabatic compression. The dry alkali or amine salts are shock-sensitive and the sodium salt ignites on contact with water. Incompatible with amines, strong acids, strong bases, strong oxidizing agents, strong reducing agents, copper, copper alloys, lead, lead alloys. Flammable. Store under an inert atmosphere.
Toxicology

Harmful if swallowed, inhaled or absorbed through skin. Irritant. May cause cyanosis, which can be delayed up to 4 hours. Typical TLV 100 ppm.
Toxicity data
(The meaning of any abbreviations which appear in this section is given here.)
IHL-MUS LCLO 18 g/m3/2h
IVN-RBT LDLO 750 mg kg-1
ORL-RAT LD50 940 mg kg-1
ORL-MUS LD50 950 mg kg-1

Risk phrases
(The meaning of any risk phrases which appear in this section is given here.)
R5 R10 R20 R21 R22.

Transport information

(The meaning of any UN hazard codes which appear in this section is given here.)
Hazard class: 3.0. Packing group: II. UN No 1261.
Personal protection

Must not be used without carrying out a prior risk assessment. Safety glasses (face mask if working with anything other than trivial amounts) and good ventilation required.
Safety phrases
(The meaning of any safety phrases which appear in this section is given here.)
S41.

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