Adding FO to HP Soap?

[LBussy]

I am going to be soaping today and the FO lists a flashpoint of 160. I suspect that means I am not going to be able to add it at trace.

Aside from adding it as I cool the soap, are there any other tips? I failed to get a good mix last time with even a CP when the trace for too heavy - how can I get this mixed thoroughly?

 

[The Efficacious Gentleman]

Are you adding in to HP or CP soap? If HP, I would never add anything like scent at trace, but when I am looking to mould up. One thing I find helps when mixing in a scent to HP is to mix the scent with some of the superfat. Depending on whether you are doing a specific super fate or just a lye discount will change how best to do it:

If just doing a lye discount, scoop out about 1% of the total oil weight just before you add the lye and keep it to one side, although you might need to keep it warm. Add the scent to this oil mix and mix it through after the cook, before moulding.

If doing a specific super fat, do the above but with the full amount of superfat.

In both cases, the extra fluid helps to spread the scent really well, I find.

 

[LBussy]

Yes HP - sorry I was thinking it real hard while typing but apparently it never made it to the keyboard.

So I am using 5% superfat, and 5% each SHea and Lanolin. I'm guessing the Lanolin may be a better one to use as it has the lower saponifiables? Or 2.5% of each? Tricky but I can do it.

 

[The Efficacious Gentleman]

I think just picking one to mix the scent in to out be okay - it'll be mixed in well enough anyway

 

[Seawolfe]

You want your HP recipe to use "full water" which is basically the default on soapcalc.

I do like EG says, mix the scent with the SF or just a bit of the oils. Once the cook is done I move the batter to another bowl to start the cooldown (leave behind the dry bits), and just as soon as I think its safe I stir in the scent and oils, mix really well with a silicon spoon and glop it into the molds.

Also remember that because the scent isn't exposed to the saponification reaction, you generally need only half the amount of FO or EO that you would use in CP.

 

[wetshavingproducts]

What Seawolf said.

Flashpoint is not the temperature at which a FO will instantly evaporate, it is the temperature at which the FO will ignite if exposed to a spark. They are related, but flashpoint means that enough ignitables are evaporating at that temperature that the FO can ignite.

I have no idea if higher FP oils evaporate any slower.

 

[LBussy]

Yes, flashpoint is the boiling point of the carrier oils ... so I'd still prefer not to go past it.

Thanks, I'll withhold the superfat amount in 50/50 shea/lanolin and call it good.

 

[Seawolfe]

To my tiny mind, its important that all of the lye is saponified during the cook, so I do something like 1-2% superfat before the cook, and add the rest after the cook. I cant tell if you are superfating at 5%, or 5% before the cook and 5% after with the shea and lanolin - but just something to throw out there.

 

[LBussy]

We're on the same sheet of music. I did add 2.5% superfat to the main mix, and use the remaining 2.5% to add in the FO.

 

[LBussy]

Came out pretty good:

I didn't get a good brush soak there, and the soap is only a few hours old, but I'm pretty happy with it.

It's "shinier" than it looks there. Sorta like a good seven minute icing.

 

[Crombie]

Flashpoint is a term used in candle making and means nothing in soaping. There is no way to get your soap batter hot enough that it will ignite.

 

[wetshavingproducts]

Flashpoint is a term used in candle making and means nothing in soaping. There is no way to get your soap batter hot enough that it will ignite.

CPOP is cooked at 170-190, so yes, it can ignite if a spark is present and low FP oils are used.

 

[Crombie]

Your Soap Will Not Ignite

Please, please show me one example of a soap that has ever ignited. I CPOP all the time with low flash point EOs.

In general, flashpoint is a term used for candle making and for those who ship EOs and FOs. In soapmaking, adding EOs (or some FOs) when your batter is hot may cause the fragrance to dissipate and not be as strong. However, when I HP, I add immediately at the end of the cook and get in the mold. Otherwise, it does not have good fluidity and does not come out smooth.

Flashpoints are an issue with candle makers and one of the reasons they have to pay higher insurance costs.

I spent some time searching the internet and could not find where any loaf of soap has ignited.

 

[LBussy]

Please, please show me one example of a soap that has ever ignited. I CPOP all the time with low flash point EOs. [...] I spent some time searching the internet and could not find where any loaf of soap has ignited.

Well then it must not have happened! :grin:

Okay seriously, what we're talking here is about solvent fumes in proximity to a source of ignition. We are not talking about soap bursting into flames. Here's a couple references for you:

"Flash point" is defined by OSHA (U.S. Occupational, Safety and Health Administration) and the DOT (U.S Department of Transportation) in the U.S. Code of Federal Regulations (CFR) as: "The minimum temperature at which a liquid gives off vapor within a test vessel in sufficient concentration to form an ignitable mixture with air near the surface of the liquid."

49 CFR 173.120; Class 3- Definitions.
29 CFR 1910.106; Flammable and Combustible Liquids.

If/when we add a low flash point EO/FO to a HP soap (we are talking about HP here) that is > the flash point, we create a flammable vapor consisting of the carrier solvent. You can believe me or not that filling the area with a flammable vapor is dangerous, but I'm here to tell you it is and I'm going to avoid it. Search the Internet for solvent fumes and fires and see if that's ever happened.

So the issue is HP and low FP solvents. The takeaway is to not add the EO/FO's with low FP until you have reduced the temperature safely below the flash point. That's just some common sense advice based on the science of flammable solvents.

 

[The Efficacious Gentleman]

Interesting points.

I do find that HP directly after the cook can be hotter than a lot of the flash points and therefore likely to result in flammable fumes, I wonder if the amounts that we use is also a factor in this -

3% is a usual amount and coupled with the size of the areas in which we generally work........is it enough of a concentration to cause a problem? Maybe.

Also the sorts of tools - I can imagine that CPOP in a gas oven or a double boiler on a gas hob could be an issue, because it would be so much closer to a source of ignition.

Personally, it's something that I am mindful of, but I would push it slightly if the flashpoint was rather low and I wanted to mix it in before the batter got too cold to be workable. I think with some recipes and scents it is really a trade off on that front.

 

[LBussy]

All true - a person needs to be informed to make an informed decision I guess is my point.

 

[Crombie]

Flashpoints: Your Soap Will Not Ignite

"Flashpoint is the temperature at which a pure, not mixed or diluted fragrance oil will combust or burst into flames when given an open flame. With CPOP soap, there is no open flame and the fragrance oil has been diluted by over 95% by your soap mixture." ~
Professor Kevin M. Dunn, author of Caveman Chemistry and Scientific Soapmaking
(there is no open flame with HP either, unless, perhaps, you are working with a gas stovetop - but, in that instance, it really would not matter what the temperature of your soap is!)

This article is an interview of Kevin Dunn (soap chemist) and Robert Tisserand (EO expert). Keven says it is BOILING point that should concern you, not flash point. Most boiling points of EOs are too high to be reached by ANY soaping process. Flashpoints are a concern with candle making and with the shipping of some EOs/FOs.

http://roberttisserand.com/2011/06/essential-oils-in-soap-interview-with-kevin-dunn/

There are a lot of soapmakers that think flashpoint is important; however, I put more faith in the soap chemist and EO expert; especially, since no soapmaker has ever been able to say that they had a fire from an EO based on the temperature of their soap.

And, with that, I'll shut up. But, please, post your photos of your soap catching on fire next time it happens.

 

[Obsidian]

I used a low flash point FO in HP before and it did not burst into flames. It did how ever "burn" off and produce lots of noxious fumes, the scent that was left morphed considerably and the house stunk for days.
Now I'm mindful of flash point just so I don't try and poison myself with cooked fumes.

 

[Seawolfe]

I wouldn't be worried about explosions, but I would be concerned about what Obsidian just mentioned. Seems a waste to just burn off the scent, and who knows what gets left behind.

 

[goji_fries]

Just a quick note on flashpoints,

Flashpoint is: heating the liquid to a temp where it will produce vapors that in the presence of spark or flame will ignite the vapor produced by the liquid. It is possible to confuse this with auto-ignition temperature. AIT is where the temp is so ihgh that it spontaneously combusts.

When I steam down essential oils, there is a flame present from fire or from my burner. Since, say something like eucalyptus has a flashpoint of something like 118f, I definitely keep the volatile oil away from a flame or spark via long tubing. In soap mixtures, I don't know if this necessarily applies. :smile: