Lamp Oil , Kerosene & Paraffin

[Flibby]

So I've seen a lot of posts all over the internet about oil lamps in boats, cabins, and generally indoors. There's lots, and I mean lots, of misinformation out there about the differences between kerosene, paraffin, and lamp oils in general.

I've done some research into it all and thought I'd share.

Here in Southern California I can purchase Lamplight Farms "Ultra-Pure" Paraffin Lamp Oil which the Lamplight web site says is "99% pure paraffin." But of course what is paraffin and how does it compare to kerosene?

There are lots of posts on this topic not only in cruising forums but all over the 'net, and every single one I've run across is wrong.

First off you need to know what ALKANES are. They are simple hydrocarbons with one or more carbon atoms strung together, and hydrogen atoms connected to them.

The simplest is methane. We all have heard of that. Methane is "C1" because it has one carbon.

You go up from there. From light to heavy. Methane is a gas at room temp. As you string more carbon atoms together the molecule gets heavier, oily-er, and eventually waxier.

The issue is that few people realize that what we consider kerosene, paraffin, mineral oils, jet fuel, etc. are not one substance but a range of alkanes that may vary from locale to locale or even from batch to batch.

As the book "Toxological Chemistry" by Stanley E. Manahan states, Kerosene is a mixture of primarily C8-C16 hydrocarbons. "General, Organic, And Biological Chemistry" by H. Stephen Stoker states that Vaseline (petroleum jelly) is a mixture of predominantly C25-C30 alkanes. Much heavier, much waxier.

Mineral oil (NOT mineral spirits) involves alkanes in the C18 to C24 range. Paraffin oil has no real defined usage but may be somewhere between kerosene and mineral oil.

Interestingly, Lamplight's own MSDSs (Material Safety Data Sheets) on its "Ultra-Pure" lamp oil show a change in the product over the past few years.

The MSDS from 2003 states that Ultra Pure Lamp Oil at the time was made from a "Mixture of Tetradecane, Pentadecane, and Hexadecane" which means it had C14-C16 alkanes in it only. A fairly refined product. That same MSDS shows that its flashpoint was 250°F (121° C) which is quite high. Its melting point was 48-50°F meaning it was very waxy and would easily gum up in colder weather.

A more recent MSDS from 2007 states that the same Ultra Pure Lamp Oil by Lamplight Farms is made up of "C5-20 Paraffins." This means that the tolerance of compounds has increased substantially and that it's not nearly as refined as it was. You get very light alkanes along with very heavy, waxy ones in the same bottle. The flashpoint has dropped to 207°F (97° C) and the melting point has also dropped to around 32 degrees F.

This is a substantial change in the composition of the product over a short span of time, and a certain percentage of the product apparently now consists of alkanes that are lighter and more volatile than typical kerosene!

But the point of all this is that separating "kerosene" and "paraffin" lamp or heating oils into two distinct substances is foolish. They are actually made up of an overlapping range of alkanes and most likely they change depending not only on where you are in the world but what materials happened to go into the container on a specific manufacturing date.

And finally I'd like to turn my attention to the assertion that you shouldn't use "paraffin" oil in flat-wick lamps, only in oil-candles with round wicks. This may have been true at a time when paraffin oil consisted of heavier alkanes. Now it appears that at least the Ultra-Pure brand is "cut" with simpler alkanes, so gummed-up wicks may be a thing of the past. I know that I use my current batch of paraffin oil in lamps with wicks of 7/8" with no problems whatsoever.

However, by the time you read this, the formulation may have changed on this product, or similar products may have widely different ingredients.

[roverhi]

My DenHaan trawler lamp requires lamp oil. Mineral spirits, which I've used instead of kerosene in all sorts of lamps for going on 40 years, will cause flare ups in the round wick trawler lamp. Apparently mineral spirits has too low a vaporization temperature and gases off too low on the wick causing major issues. Before I discovered the problem, lamp would send carbon floating through out the boat and make an ungodly mess. Lamp would not maintain a level requiring constant adjustment to keep it burning cleanly. Once I switched to 'Lamp Oil', it's worked without a problem.

Don't know how that fits in with the above report but lamp oil is not kerosene or mineral spirits.

[Flibby]

Mineral SPIRITS (unlike mineral OIL) are usually made up of alkanes of much higher volatility (lower molecular weight), often with benzene or other toxic aromatic compounds mixed in. Maybe in the range of C5 to C12. These should never be used in lamps due to high toxicity and low flash point.

"Odorless mineral spirits" have the toxic aromatic compounds removed but still have a low enough flashpoint that they should generally not be used in lamps, though they're not hugely different than kerosene. You could arguably get away with it.

[djmarchand]

Kerosene is the only product mentioned that has a real specification and there are a number of grades Jet A1, K1, etc that meet various ASTM detailed specs for boiling range, flash point, sulfur content, etc.

All of the others: paraffin, lamp oil, mineral oil, etc are products that have no real definition, only what commonly accepted usage has come to mean.

And even plain kerosine has no real spec. It is used by the refining industry to mean any intermediate product that can ultimately be refined/blended into one of the ASTM grades.

[GordMay]

Greetings and welcome aboard the CF, Flibby.

Thanks for sharing your expertise.

[andypack]

Interesting! I had no idea. Here are some additional details of how these get called different names in different countries. Kerosene - Wikipedia, the free encyclopedia

[Sam Plan B]

I use charcoal lighter fluid in my lamps. It has no oder and does not smoke. I used it all last Winter with no problems.