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I think that is the main point to consider in this question: Is it an easy enough alternative? Using high quality stainless steel instead of plastic or silicone for soap making: mixing bowls, utensils, measuring cups/pouring vessels, lye solution mixing and long term storage for master-batched lye solution, etc. etc. should certainly be possible, but at very high cost. Doable, for some, not for others. And to pass the cost on to customers, one would run into other challenges as well.

My point is that what may be easy for you (if you have the where-with-all) is not necessarily easy for every soap maker.

Those things are not in my budget unless perhaps used. So, I will wait until I can invest in that type of equipment before starting.

I am totally on board with reducing one's impact on the environment. I think if you have the resources and capital available to make your soapmaking comply with the suggestions made by the researchers who conducted this study, then go for it! I'd also encourage correlating the results of this study with other similar research to have the best possible understanding of what's happening when these plastics are "stressed". One study isn't really a large enough body of evidence.

I wonder if this is a case of fighting the wrong fight. We should be concerned about what we're allowing into the environment, but there are things we all can do that will make a much larger difference. Choosing public transport or bicycling, carpooling, reducing use of fossil fuels. Recycling anything - properly - and reducing landfill waste. These things can be easily done on a wide scale and will have the greatest impact on the environment as a whole. If the manufacturing process of plastics CAN be changed, then that may help, but that's out of our control.

For me, it won't change my practice. As a hobbyist, I'm not concerned enough that any hormones leached from plastic will be enough to make any sort of impact on my body. The money I would need to spend on supplies would be prohibitive to me enjoying my creative outlet, so for me it just doesn't make sense. And at any rate, I think it's a better focus for me to try to modify my diet and exercise to keep my body healthy. Your mileage may vary, of course.

The effects are well known enough (through several studies, not just one) for many manufacturers to have switched to BPA-free plastic. What they don't tell the consumer, however, is that they often replace BPA with another estrogenic plasticizer as bad or worse.

That said, I mentioned the study not to change the ways of anyone in this forum--only because you asked about it and because I felt it good to explain why I personally don't want to use plastics unless necessary and, where I must, with lower-temperature oils that won't cook in plastic.

My own view is that this is not the wrong fight. It's just one of many, a drop in the bucket. We live in a very imperfect world that I fear will get worse at a faster pace than it will improve. But that my landlord's landscapers spray Roundup outside of my organic veggie garden and thirdhand smoke makes its way onto my garden doesn't suggest to me that I should stop my organic gardening efforts and go "hog wild" with chemicals (e.g., pesticides) and cancer-causing substances. My efforts will reduce the overall burden on my body.

But, again, there is only so much that each one of us *can* do. I understand that we are each more capable of some changes than others. Carpooling for you may be easier than using stainless in parts of the soaping process whereas stainless would be an easier change for me to make. I mentioned the study not to twist anyone's arm, only to explain my own questions and concerns for the process I am trying to design for myself.
 
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I think it is a step on the right direction, AZJen, and I am glad you are following your conscious on this. I have tried to convince my loved ones not to heat food in plastic containers in the microwave oven; apparently some heed and some do not. I find the evidence when I look at the plastic containers with burnt & peeling inside surfaces in the cupboards. If that's in my kitchen, it gets tossed. If my husband doesn't care, at his age, he can make that decision for himself, of course. But I will not re-use that container. Less for what I know it will leach into the food that may later be stored in it, but for I don't know may leach into the food. But really, even more because I know that the damaged surfaces of the interior of the plastic too easily escapes proper cleaning and can facilitate pockets for contamination inside the container. So for me that is a big deal for food containers. A smooth surface is important to me when storing food inside the fridge or elsewhere.

Of course I don't cross-contaminate food storage and soap making containers made of plastic. I really do believe that to be unwise, no matter how well they are cleaned. But some folks report that the stainless steel containers they use for soap do dual duty with food usage. I do have several SS containers I use for soap making, but only one of them have I ever used for food after making soap in it. It's a good size to hold a bag of micro-waved popcorn, so I've used it for that once or twice. But other than that, I just keep my soaping supplies and food making supplies separate because it is easier for me. If I lived in a smaller house or an apartment, however, I think I would not worry about using SS for both soap and food and could reduce the number of over-all containers in my home.
 
I apologize if I seemed like I was accusing you of attempting to change the practices of the forum at large - I simply wanted to convey my thought process.

On a slightly different note, I brought up the subject to my boyfriend who works in the plastics industry. He confirmed that plastics labeled BPA-free are pretty much a scam, containing other plasticizers and compounds that are just as bad or worse. He did say, though, that the process for making silicone is extremely different and doesn't require any plasticizers like the compounds that are in question. It's possible that that might help you decide whether or not to include those products in your soapmaking arsenal.
 
Those things are not in my budget unless perhaps used. So, I will wait until I can invest in that type of equipment before starting.

The thrift store is a great place to look for stainless steel at a bargain price. I sometimes see Revere Ware or Farberware cooking pots, which if you don’t mind the handles, would be perfect for making small batches of soap. I’ve managed to find stainless steel bowls of various sizes that I purchased for a couple of dollars each. I don’t know where you are on silicone, but I also see silicone spatulas all the time, and my favorite SS spoon for mixing lye is also from the thrift store.

I know a scientist who is very active in pollutant research. In his younger days, his research contributed to the eventual US ban on flame retardants in sleepwear for children. He thinks “micro” plastic contaminants are one of the greatest environmental threats of our time. I cringe a little when I see people heating their lunch in a plastic container because that potential exposure can be avoided easily with the sacrifice of only a little convenience. My goal is always to minimize exposure to any compounds that may have long term health risks, but it’s not always easy or practical. Plastics are increasingly everywhere, but with the right equipment we should be able to minimize them in our soaps. Considering relative risks, I personally am not ready to rule out the use of high quality plastic containers in soap making because I feel they make the activity safer in other ways. However, I appreciate your perspectives on the matter and consider them good food for thought.
 
I apologize if I seemed like I was accusing you of attempting to change the practices of the forum at large - I simply wanted to convey my thought process.

On a slightly different note, I brought up the subject to my boyfriend who works in the plastics industry. He confirmed that plastics labeled BPA-free are pretty much a scam, containing other plasticizers and compounds that are just as bad or worse. He did say, though, that the process for making silicone is extremely different and doesn't require any plasticizers like the compounds that are in question. It's possible that that might help you decide whether or not to include those products in your soapmaking arsenal.

I appreciate that you shared your thought process, Steffamarie, and thank you for clarifying that you were not accusing me of attempting to change the practices of the forum at large.

I also very much appreciate the suggestion that silicone might be a safer choice for molds and such. I had assumed worse but hadn't researched it, yet. (I now have a conventional-turned-naturopath doctor of a customer. He may also be able to shed some light on the matter.) After your suggestion, a brief Google search turned up rough confirmation (third party reports) that silicones don't contain plasticizers and similar compounds. I also found this helpful page which suggests that lower temperatures even with high fat products may be fine even for food use (e.g., baby bottles). I still don't know how hot soap gets while saponifying (it seems that most are letting this process happen outside of a refrigerator and with insulation from a towel), but I'm guessing much below 200 degrees. So, silicone may be the safer choice for molds as I think that even freezer paper has a plastic lining. But if saponification happens at a reasonably low temperature, even freezer paper may be acceptable from my perspective.
https://masonbottle.com/blogs/news/49464836-is-silicone-really-safe-will-it-ever-leach-chemicals

Oh, boy. Just found this.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4884743/
"In conclusion, it should be noted that the safety of application decreases with the decrease in silicone particle size. This is due to the possibility to overcome biological membranes and skin barriers by low molecular siloxanes, which demonstrate a lipophilic character according to the rule of Lipinski. The bioavailability and also permeation of compounds through the skin layers is possible, when they meet the following conditions (Lipinski, 2000; Lipinski et al., 2001; Mojsiewicz-Pieńkowska, 2014):

  • (1)
    there are less than 5 hydrogen-bond donors (Expressed as the sum of hydroxide groups OHs and amine groups NHs);

  • (2)
    molecular Weight is less than 500;

  • (3)
    the Log P is less than 5;

  • (4)
    there are less than 10 hydrogen-bond acceptors (expressed as the sum of nitrogens and oxygens).
Therefore, consideration of siloxanes toxicity should be always referred to a particular compound, which may be low molecular, medium molecular (oligomer) or a high molecular weight (polymer), but not to the entire chemical group. Actually, particle size and chemical structure determine their physicochemical properties (e.g., solubility, lipophilicity, log P, volatility), ability to penetrate and permeate through skin layers, ability to overcome cellular barriers and toxicity. Moreover, low molecular weight silicones can change the structure of lipid bilayer, by the fluidization or even extraction of the lipids (Glamowska et al., 2015; Mojsiewicz-Pieńkowska et al., 2015; Yang and Guy, 2015). This effect can weaken the natural barrier of cell membranes (Glamowska et al., 2015;Mojsiewicz-Pieńkowska et al., 2015). Low molecular weight silicones can accumulate in the organism, and affect the organs in the long-term perspective (Wang et al., 2013). The least safe are cyclic siloxanes and low molecular weight linear siloxanes (Flassbeck et al., 2001; Gaubitz et al., 2002; Papp et al., 2004; Tran et al., 2015; Xu et al., 2015). Additionally, their volatility poses a threat of entering to the organism through the respiratory system (Genualdi et al., 2011; Kierkegaard and McLachlan, 2013; Tran et al., 2015; Xu et al., 2015)."
 
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Oh, boy. Just found this.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4884743/
"In conclusion, it should be noted that the safety of application decreases with the decrease in silicone particle size. This is due to the possibility to overcome biological membranes and skin barriers by low molecular siloxanes, which demonstrate a lipophilic character according to the rule of Lipinski. The bioavailability and also permeation of compounds through the skin layers is possible, when they meet the following conditions (Lipinski, 2000; Lipinski et al., 2001; Mojsiewicz-Pieńkowska, 2014):

  • (1)
    there are less than 5 hydrogen-bond donors (Expressed as the sum of hydroxide groups OHs and amine groups NHs);

  • (2)
    molecular Weight is less than 500;

  • (3)
    the Log P is less than 5;

  • (4)
    there are less than 10 hydrogen-bond acceptors (expressed as the sum of nitrogens and oxygens).
Therefore, consideration of siloxanes toxicity should be always referred to a particular compound, which may be low molecular, medium molecular (oligomer) or a high molecular weight (polymer), but not to the entire chemical group. Actually, particle size and chemical structure determine their physicochemical properties (e.g., solubility, lipophilicity, log P, volatility), ability to penetrate and permeate through skin layers, ability to overcome cellular barriers and toxicity. Moreover, low molecular weight silicones can change the structure of lipid bilayer, by the fluidization or even extraction of the lipids (Glamowska et al., 2015; Mojsiewicz-Pieńkowska et al., 2015; Yang and Guy, 2015). This effect can weaken the natural barrier of cell membranes (Glamowska et al., 2015;Mojsiewicz-Pieńkowska et al., 2015). Low molecular weight silicones can accumulate in the organism, and affect the organs in the long-term perspective (Wang et al., 2013). The least safe are cyclic siloxanes and low molecular weight linear siloxanes (Flassbeck et al., 2001; Gaubitz et al., 2002; Papp et al., 2004; Tran et al., 2015; Xu et al., 2015). Additionally, their volatility poses a threat of entering to the organism through the respiratory system (Genualdi et al., 2011; Kierkegaard and McLachlan, 2013; Tran et al., 2015; Xu et al., 2015)."
That article relates to exposure via application of very small particles on the skin or via ingestion. What you probably want to know is whether or not (or at what rate, e.g. very, very slowly) silicone molds or spatulas will release very small, molecular wt particles into soap batter.
 
That article relates to exposure via application of very small particles on the skin or via ingestion. What you probably want to know is whether or not (or at what rate, e.g. very, very slowly) silicone molds or spatulas will release very small, molecular wt particles into soap batter.

It also mentioned inhalation (they volatilize, it appears). Thank you! I had assumed that products such as molds might contain none of the lower weight particles. I wonder who could answer such questions about what spatulas and molds (ice, soap, baking) are made of and, if they contain lower weight particles, at what rate they release into soap batter or water. Knowing the temperature range I might expect during saponification would help.
 
I think there's also something to be said for the potential toxins that are in wash-off products vs potential toxins in food. My kids can't eat BHA, BHT, or TBHQ. Nor do I buy deodorant or lotions with those ingredients in them, due to absorption through the skin. However, many on this board swear by them as antioxidants. I probably wouldn't buy a wash-off product with those, just because there are other choices, but many soapers have found that those are necessary ingredients to achieve their ends.
I do put warm oils in plastic bowls and my moulds are silicone or milk cartons. I never heat any plastic in the microwave for any reason. We've all got our lines in the sand ;-)
 
Personally I think we all should be cautious about environmental elements around us, however, not to the point of being absolutely terrified of everything that could be potentially bad for us. If that were the case we would all just stay in bed with the covers over our heads and cower at life.
JMO -
We have to decide what we are and are not comfortable with.
 
It also mentioned inhalation (they volatilize, it appears). Thank you! I had assumed that products such as molds might contain none of the lower weight particles. I wonder who could answer such questions about what spatulas and molds (ice, soap, baking) are made of and, if they contain lower weight particles, at what rate they release into soap batter or water. Knowing the temperature range I might expect during saponification would help.


I would suspect you could contact a major producer of such items and request some feedback from one of their plastics engineers who may be able to address some of your concerns. It may be a long shot that the company will pass your inquiry on, but worth a try. One of my brothers has his degree as a plastics engineer and worked in the field for a number of years, but has been retired from it now for over a decade. I don't think he has kept up with all the changes in the field since he left, because he has pursued other avenues of interest that require a lot of his time and energy. Perhaps if you can find someone like that in your circle of acquaintances you might be able to get some answers, or even a referral to a forum where they talk with each other on topics such as this.

For the most part, however, I believe most silicone spatulas we use in soap maker were specifically designed for use as food preparation utensils and did not have soapmaking in mind when they were being developed and tested. If you contact one of the major producers of such items, they are likely to state a disclaimer about using their products for activities other than their intended design purpose.
 
Based on the following statement, I'm guessing that silicone molds used for baking and soaping are made of the high molecular weight silicone polymers. "Polymers of moderate molecular weight are fluids, while high molecular weight, slightly cross-linked polymers are elastomeric. " https://www.sigmaaldrich.com/materials-science/material-science-products.html?TablePage=20204339

I'm presently leaning toward silicone molds, but I'll try to pick a few brains outside of this forum. Thank you greatly for your feedback!
 
Re: plastics: Certain plastics should never be used with lye, but there are two that are safe: HDPE #2, and PP#5. I mix my lye in a tall Rubbermaid pitcher made of PP #5, and I store my lye solution long term in a (thoroughly washed/rinsed) reclaimed liquid laundry detergent bottle with a tight-fitting screw-top cover all made of HDPE #5. I master-batch my lye and it lasts forever in my reclaimed detergent bottle without harm to the plastic or the lye (for 2 years and counting).

IrishLass :)[/QUOTE]

Hi IrishLass, Thanks for your input. How do you master-batch your lye solution when each oil has a different lye amount that it will need or is your recipe constant? How does this work?
 
Not IL, but the way one masterbatches lye is to mix the dry lye with the water at a specific amount (quite often 50% concentration - which equals 1:1 lye to water). This is the masterbatch.

When one measures out he required amount of lye solution and add the extra water based on the specific recipe. There is a calculation for figuring out how much more water is needed, but if you use the Soap Making Friend lye/soap calculator it will do the calculation for you.

If you use a different lye calculator, you will have to figure it out manually. For a 33% lye concentration (or 1:2 lye to water) the calculation is: (2 x the lye weight as ID'd by your lye calculator = the weight you need of your 50% masterbatch solution) + (1/2 the lye weight = the extra water weight). That totals a 33% lye concentration. There are many threads here at SMF that address masterbatching lye solution, so if you do a search you can find more detail about the calculations required.

But it's really nice to use a calculator that does the math for you, which is on reason why so many soapmakers are really liking the Soap Builder (Soap Making Friend) lye calculator here.
 
Yesterday, I found another study on siloxanes migrating into food.
https://pdfs.semanticscholar.org/d63b/8dae052a78719743c5007cd610572255e3a8.pdf

Long baking times, high fat foods, untempered molds (not sure how to find tempered molds since most product listings don't give that info.), and fat being absorbed by the silicone then leached back out (especially problematic if rancid and able to prematurely spoil a new batch) were the biggest problems named. Based on this study, I'd consider tempered molds used at lower temperatures (hopefully the batter doesn't heat up a lot during saponification; nobody has answered this question, yet, so I'll have to find out after investing in the equipment) and for a short duration (not long enough for the oils trapped in the mold to become rancid). Safely used silicone molds, parchment paper (which is lined with silicone), or freezer paper (lined with more silicone, I believe) for temporary use seem to be the only viable options.

What in the world did they do before the days of silicone is one lingering question! Since soap is said to not release from non-silicone molds with ease, I'm guessing the imperfections at the edges and bottom had to be cut off. More time and more waste were a part of life?
 
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Yesterday, I found another study on siloxanes migrating into food.
https://pdfs.semanticscholar.org/d63b/8dae052a78719743c5007cd610572255e3a8.pdf

Long baking times, high fat foods, untempered molds (not sure how to find tempered molds since most product listings don't give that info.), and fat being absorbed by the silicone then leached back out (especially problematic if rancid and able to prematurely spoil a new batch) were the biggest problems named. Based on this study, I'd consider tempered molds used at lower temperatures (hopefully the batter doesn't heat up a lot during saponification; nobody has answered this question, yet, so I'll have to find out after investing in the equipment) and for a short duration (not long enough for the oils trapped in the mold to become rancid). Safely used silicone molds, parchment paper (which is lined with silicone), or freezer paper (lined with more silicone, I believe) for temporary use seem to be the only viable options.

What in the world did they do before silicone is one lingering question! Since the other options don't release the soap from the mold with ease, I'm guessing the imperfections at the edges etc. had to be cut off. More time and more waste were a part of life.


AZJen, watch a video on the making of Allepo soap and you will see an old-world method of pouring and cutting soap that does not use any mold lining methods or molds as we know them. They pour the soap on the floor and wait until it is ready to cut and remove for stamping and stacking. It does not look like they have any waste to be concerned about.

Here is one:

 
Amazing, earlene! I'd found that video a few days ago but didn't watch it from start to finish until just now. The floor is covered in large sheets of wax paper before they pour. Maybe that paper has a thicker coating of wax than paper found here, and maybe the paper is thicker. I've read from some to turn the waxy side of the paper away from the soap, but then it seems the paper would bond to the soap. I guess I ought to watch a few more videos on that subject and read a few more threads.
 
I doubt waxed paper was used centuries ago, though, considering that they say it is a centuries old method. Perhaps linen or some other fabric may have been used, though.

Here is another link to lining molds with oil cloth, another alternative some soap makers use:



I don't know how you feel about oil cloth specifically, but it's another jumping off point for your own personal brainstorming when trying to think of alternatives to the materials you prefer to avoid. My niece uses homemade diaper liners she makes using lanolin to waterproof fabric, just the same idea of how dusters were made waterproof for cowboys. And pretty much the same way those beeswax wrappers are made for wrapping sandwiches.
 
Not IL, but the way one masterbatches lye is to mix the dry lye with the water at a specific amount (quite often 50% concentration - which equals 1:1 lye to water). This is the masterbatch.

When one measures out he required amount of lye solution and add the extra water based on the specific recipe. There is a calculation for figuring out how much more water is needed, but if you use the Soap Making Friend lye/soap calculator it will do the calculation for you.

If you use a different lye calculator, you will have to figure it out manually. For a 33% lye concentration (or 1:2 lye to water) the calculation is: (2 x the lye weight as ID'd by your lye calculator = the weight you need of your 50% masterbatch solution) + (1/2 the lye weight = the extra water weight). That totals a 33% lye concentration. There are many threads here at SMF that address masterbatching lye solution, so if you do a search you can find more detail about the calculations required.

But it's really nice to use a calculator that does the math for you, which is on reason why so many soapmakers are really liking the Soap Builder (Soap Making Friend) lye calculator here.

Ohhh thanks, thats awesome. I never knew that. Thanks for the great explanation and the website to aid in this. I like the website too its pretty sleek. I'll have to start master batching. Thanks again!
 
Wikepedia is saying this about oil cloth:

"Oilcloth, also known as enameled cloth or American cloth, is close-woven cotton duck or linen cloth with a coating of boiled linseed oil to make it waterproof. Historically, pre-Mackintosh, oilcloth was one of very few flexible, waterproof materials that were widely available. Leather was expensive—very expensive in large pieces—and required regular maintenance if often wetted. Oilcloth was used as an outer waterproof layer for luggage, both wooden trunks[1] and flexible satchels, for carriages and for weatherproof clothing.[2]"

"By the late 1950s, oilcloth became a synonym for vinyl (polyvinyl chloride) bonded to either a flanneled cloth or a printed vinyl with a synthetic non-woven backing." [I note that vinyl at least sometimes contains phthalates.]​

Hardened linseed is basically very rancid flax seed oil, I think (but perhaps past the stage of being able to make other oils rancid???); so I'm not sure how that would affect soap. I guess it might depend on whether antioxidants are used and how prone to rancidity the soap's oils are.

Normally I avoid hydrogenated oils, but if the hydrogenated olive oil "silicone" is truly unsaponifiable, that may be the most promising 'liner' option, yet. I'm also thinking to try a micro batch (one bar), once I buy some lye, in very small stainless containers that I already have. If those work well enough once cured for enough time at room temp or after put in the freezer, it may be safe to assume that the same may be true for a larger container.
 
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I doubt waxed paper was used centuries ago, though, considering that they say it is a centuries old method. Perhaps linen or some other fabric may have been used, though.

Here is another link to lining molds with oil cloth, another alternative some soap makers use:



(I couldn't find a way to delete the comment just before this one; so, I edited it as if it would follow this one.)

I don't know how you feel about oil cloth specifically, but it's another jumping off point for your own personal brainstorming when trying to think of alternatives to the materials you prefer to avoid. My niece uses homemade diaper liners she makes using lanolin to waterproof fabric, just the same idea of how dusters were made waterproof for cowboys. And pretty much the same way those beeswax wrappers are made for wrapping sandwiches.



I will take a look at the oil cloths, earlene! And making my own cloth liners with lanolin seems a great possibility especially after reading that lanolin is almost completely unsaponifiable as well as used in some soaps. Whatever is saponifiable might be removed by the first batch.

Additionally, I've been playing with three additional ideas. One is that soap may unmold from bare stainless steel if put in the freezer for a short while (15 minutes to 3 hours). I've heard that soapers do such with other molds. More cure time in the mold at room temperature may also cause enough shrinkage to release it from the stainless container. And the third idea is a really just a discovery. While looking at parchment paper lined with silicone (disposable seemed better than reusing silicone molds that absorb oils which can then become rancid), I found a product lined with a vegetable form of "silicone": https://www.amazon.com/gp/product/B075B7LBJ7/ref=ox_sc_act_title_3?smid=AWKM4HK9OSLXS&psc=1. Google then turned up some science about the product. It's (partly or completely?) hydrogenated olive oil that is not saponifiable (at least not with usual amounts of lye, I believe). Sounds promising! The word AND in the following description from a website seems to imply that some of the hydrogenated product is saponifiable. "Vegetable-derived Silicon replacement with vegetable-derived squaleneHydrogenated Ethylhexyl Olivate and Hydrogenated Olive Oil Unsaponifiables"
 
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