Bill_Toge
Forum Replies Created
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are you using deionised water?
(I ask as free metal ions can have a drastic effect on structured surfactants)
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@bohnjowers personally I’d take those ingredients lists with a HUGE pinch of salt; having battled through weeks and weeks of frustration trying to match products of this type, particularly those which have been made in China, I’ve found the best way to match them is to disregard the listed ingredients altogether, compare the product’s characteristics with those of a known formula, and modifying that formula to fit
I think you’re right in that there’s not much PVP in your benchmarks - it sounds like there’s a more fundamental difference between them and your formulas, most likely within the oil phase of the emulsion, that’s not reflected in the labelling
I might also add that since the product is non-volatile, the entire emulsion will act as a plasticiser/hardener for the resin, not just the glycerine and PEG-7 cocoate, so the sensory characteristics of your pomade will have a real impact on the hold!
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try using a different resin in combination with PVP; Advantage LC-E (or Advantage S, if you can get hold of it) is particularly good for stiff, rigid hold
having some hard/sticky waxes into the oil phase, e.g. beeswax, microcrystalline wax or lanolin wax, helps too
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Glyceryl Stearate SE (self-emulsifying) means it’s a mixture of glyceryl stearate and sodium stearate; since sodium stearate is anionic, and the HLB system is only meaningful where non-ionic surfactants are involved, that HLB value is not indicative of its power as an O/W emulsifier
and since PEG-2 stearate is typically used as a bulking agent rather than an emulsifier (e.g. as Cithrol DEGMS from Croda), my guess is that it helps in physically preventing the emulsion from separating
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no worries, glad to be of assistance!
to the best of my knowledge, the only thing apart from sodium nitrite that a) could generate nitrosonium ions (the reactive species responsible for nitrosamine formation), and b) is generally approved for use in cosmetics, is bronopol; you’ll be fine using DMDMH, no matter what amine you use
(I researched the gory details of this subject a few years back, when someone senior in our marketing department read something about nitrosamines, and got themselves into a huge panic about it)
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regardless of pH, there is no possibility of nitrosamine formation here; DMDM hydantoin is not a nitrite or a nitrite precursor, and triethanolamine is a tertiary amine (so it couldn’t become an N-nitrosamine even in the presence of nitrites)
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from my experiments with oral care preservatives in a previous job, I’d strongly suggest you avoid using phenoxyethanol and benzyl alcohol, as they both have an unpleasantly oily taste and a temporary local anaesthetic effect (i.e. they make the mouth numb for 5-10 minutes after contact)
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sodium methyl paraben is one of the most widely used preservatives in the world; hunt around for other suppliers, as someone somewhere near you is bound to stock it
if you can’t find it anywhere, try methyl paraben instead (you’ll have to dissolve it hot water first)
wouldn’t recommend using sodium benzoate for toothpaste; if your pH is above 5 it won’t work it all, and a toothpaste that acidic will damage the teeth
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in my experience, sodium methyl paraben is a good preservative for toothpaste; it’s one of the few preservatives that dissolves readily in water, is generally recognised as safe, doesn’t have a noticeable taste, and works in alkaline formulas
(given that it contains bicarbonate of soda, your formula is likely have a pH of about 8 or 9)
however, unless you’ve got an airtight mixer and a vacuum pump, you will struggle to get a smooth air-free paste
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the free fatty acid content is indicative of how fresh the oil is; if it’s above the upper limit of the supplier’s spec, it’s been significantly degraded
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in my experience, aliphatic oils with long carbon chains (e.g. coconut oil, joboba oil) are very hard to incorporate into products like shampoos; they are often the direct cause of phase separation, even when you use rheological stabilisers to prevent it
if you want to be sure your shampoo will hold together, I’d suggest knocking your oil levels down to 1/10th of what you’ve got now
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what @Perry said - provided your bulk phase is hot enough for everything to melt fully, provided you thoroughly shear the batch, and provided you take care to ensure the batch remains reasonably uniform as it cools, the laws of kinetics and thermodynamics will do the rest of the work for you
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speaking as a chemist for a company which has routinely made relaxers on an industrial scale: ensure everyone who is likely to be near the vessel is wearing safety goggles, add it slowly, and try to avoid splashing it
provided you take due care it’s pretty simple; dissolving calcium hydroxide in water is a lot less exothermic than dissolving sodium hydroxide, therefore it’s a lot more straightforward
also, for what it’s worth, we used to put it in the main vessel with the water phase and heat it up to dissolve it before we added the oil phase
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brief summary of the SCCS opinion, 2005 (link to full text):
the LD50 for dermal toxicity (the dose needed to induce lethal effects in 50% of the test subjects) was found to be greater than 10,000 mg per kg of body weight; they stopped the test at 10,000 mg per kg
assuming the average person weighs 60 kg, this means the average person would need to directly apply 600+ grams of concentrated benzoic acid/sodium benzoate to their skin before they started showing symptoms of poisoning
the rate of absorption through the skin was calculated to be 3% per hour, under an air- and water-tight patch; considering benzoic acid/sodium benzoate is typically present at 0.5% or less of a cosmetic products, and that said product is generally left open to the air once it’s been applied to the skin, almost none of it would get into the body
furthermore, there was no evidence of any carcinogenicity, mutagenicity or reproductive toxicity (characteristic symptoms of benzene poisoning) due to benzoic acid/sodium benzoate
I suspect the panic about it being reduced to benzene comes from J. Agric. Food Chem., 1993, 41 (5), pp 693–695 (link), which describes how benzoic acid can be reduced to benzene by oxygen which has reacted with vitamin C and iron/copper ions; however, mass-produced foods and cosmetics are typically made with deionised water, meaning there is typically next to no iron or copper present in the finished product
hope this helps!
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my guess is that it’s related to the tannins in your green tea, which go brown/black in the presence of iron; the first thing I’d try would be adding a chelator
in addition to the chelators Bob mentioned, I’d recommend Dissolvine GL from Akzo Nobel (INCI: Tetrasodium Glutamate Diacetate) if you want a biodegradable naturally derived alternative to EDTA
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if they just want to register the product on the Cosmetic Product Notification Portal, then ranges will be sufficient, though there are certain prescribed ranges you have to use (0.1-1%, 1-2.5% etc.)
though as @LianePamuspusan said, if you want to get it safety assessed in accordance with Annex I of the cosmetics regulations, the vast majority of assessors will want the exact formula
the finished safety report is held by the Responsible Person and is not uploaded onto the Portal; the only third party who’d need to see it would be a member state’s competent authorities (e.g. the Trading Standards Institute in the UK), who’d need to see the report if they were addressing specific safety or regulatory concerns that had been raised about the product
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what red dye are you using? some dyes are notoriously unstable towards daylight
also, benzophenone-4 goes bright yellow in alkaline formulas (e.g. bar soaps), hence the colour change
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in any case I’d suggest using a different preservative; phenoxyethanol/ethylhexylglycerin doesn’t work well in surfactant bases, and it has low water solubility
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don’t know about REACh regs, but according to Annex III/66 of the cosmetics regs, the acceptable limit for residual acrylamide is 0.1 ppm for leave-on products and 0.5 ppm for everything else
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if in doubt, ask your supplier; most reputable manufacturers have enough regulatory support in place to answer questions like this
also CosIng is by no means a complete or comprehensive source - it’s good if you want to find out if something’s on a banned or restricted list, but there are lots of ingredients on there that don’t have their CAS/EINECS numbers listed on there (as I’ve found out from compiling many safety assessments!)
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could the mods please delete this comment; I got an error message when I tried to post it the first time, thought it hadn’t worked, and ended up posting it twice by accident
cheers!
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I’d suggest you ask your plastics manufacturer if they can provide coated or metallic effect plastic containers instead
the cost per unit would be higher, but it would be a lot more reliable and less labour intensive than trying to paint them after the fact
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@Microformulation, we only passivate 316 grade steel if it’s coming into contact with reactive or metal-sensitive materials, e.g. hydrogen peroxide or thioglycolic acid
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glucosides and CAPB are not ethoxylated, and in my experience they have never had a negative effect on preservatives
also, CAPB is amphoteric (carries both a negative and a positive charge), rather than non-ionic
the only real problem I can foresee from using phenoxyethanol in a product like this would be mixing it in and getting it to stay in; it has very low solubility in water
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coal tar has been banned from cosmetics in Europe since 1999, as it’s a class 1 carcinogen (i.e. there is substantiated, relevant in-vivo data indicating its carcinogenicity); you can only use it in over-the-counter pharmaceuticals, and only if you have data to prove that it’s safe for use in that particular application
most phthalates bar DMP and DEP have been banned as well, as they are class 1 reprotoxins
as far as personal preference goes, I tend not to use triclosan because salicylic acid is more effective in liquid soaps, and CPC is more effective in oral care
apart from that, I have no issues with the others; any “x free” statements on our products are there because they’ve been requested by the customer