Forum Replies Created

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  • Bill_Toge

    Professional Chemist / Formulator
    February 5, 2017 at 4:14 pm in reply to: Pet testing & safety sheet

    it depends how much you trust the person/company you’re buying it from

    ideally, they should have done it themselves before offering it for sale

  • Bill_Toge

    Professional Chemist / Formulator
    February 1, 2017 at 2:53 pm in reply to: Homogenizers

    in this industry, homogeniser = high-speed rotor/stator mixer 

    also, if you put anything a slurry it shouldn’t hydrate at all; the idea of a slurry is that you add it to water, so that the slurried substance disperses slowly, allowing it to hydrate uniformly, and (hopefully) without lumps

  • Bill_Toge

    Professional Chemist / Formulator
    January 29, 2017 at 6:44 pm in reply to: Creating fragrance water

    @sjinesh the phenomenon you’re describing is phase separation - Ostwald ripening is something else entirely (dispersed phase becoming physically detached from the emulsion interface, which is extremely unlikely to happen in a system like this)

  • Bill_Toge

    Professional Chemist / Formulator
    January 27, 2017 at 8:17 am in reply to: Raw materials sample - GMP

    that’s very surprising!

    we (and every other UK manufacturer I know of) take the results on raw material suppliers’ CoAs as read, and ISO 22716 auditors have never had a problem with that

    apart from basic checks for colour, odour and appearance, the only tests we carry out on raw materials are on water (produced in-house, and the most sensitive raw material we use), SLES (for pH, to check it’s the right blend) and dyestuffs for hair colours (to check they’re the right colour when dyed out)

    personally, I’d dispute that conclusion

  • Bill_Toge

    Professional Chemist / Formulator
    January 26, 2017 at 3:33 pm in reply to: How to guess the percentage

    in my experience, ingredient lists on styling products are notorious for being incomplete, or just plain wrong - personally, I’d take that list with a very big pinch of salt

  • Bill_Toge

    Professional Chemist / Formulator
    January 26, 2017 at 11:01 am in reply to: Mouthwash

    @marek.barnas 1,2-diols (of which propylene and butylene glycol are examples) have antimicrobial effects; the activity increases as the chain length increases

    unfortunately, as the chain length increases, solubility decreases and the taste becomes much more unpleasant

    they can act as solubilisers as well - the effects are not mutually exclusive

  • Bill_Toge

    Professional Chemist / Formulator
    January 26, 2017 at 10:45 am in reply to: Water based hair products

    the easiest way to do that is to add a high HLB and a low HLB surfactant (e.g. PEG-40 hydrogenated castor oil and glyceryl stearate) to an anhydrous formula, so it has some means by which it can mix with water; it’ll be water-resistant, but will wash out with shampoo much more easily

  • Bill_Toge

    Professional Chemist / Formulator
    January 26, 2017 at 9:45 am in reply to: Bugs and chemicals

    has that been stored in a humid atmosphere?

    when we get samples of this and other oxidative dye precursors, the supplier typically puts a packet of silica gel in the container; in general, these substances keep well, provided the containers are sealed tight, kept cool and exposed to as little air or moisture as possible

  • Bill_Toge

    Professional Chemist / Formulator
    January 25, 2017 at 11:28 am in reply to: Water based hair products

    what benefit would water-based products have over your current ones?

    I ask as water-based products are an order of magnitude more complex than anhydrous ones, and most styling resins (which you would need to create a high-performance product) are not generally available to home crafters

  • Bill_Toge

    Professional Chemist / Formulator
    January 23, 2017 at 9:52 pm in reply to: Mouthwash

    the main ones apart from sodium benzoate are sodium methyl paraben, and propylene / butylene glycol

    bronopol used to be used a lot, but not so much these days as it causes the product to go yellow over time

  • Bill_Toge

    Professional Chemist / Formulator
    January 23, 2017 at 8:30 pm in reply to: Duochromes

    this article discusses special effect pigments in detail; duochromes are on the second to last page (“effect pigments based on silica flakes”)

  • Bill_Toge

    Professional Chemist / Formulator
    January 23, 2017 at 8:18 pm in reply to: Mouthwash

    @marek.barnas it is true; sodium benzoate is completely ineffective above pH 5

  • Bill_Toge

    Professional Chemist / Formulator
    January 21, 2017 at 6:35 pm in reply to: Victoria’s Secret Bombshell Ingredients

    the fragrance house will also have to declare any hazardous components on the MSDS (many of which are not required on the label), but only they and the manufacturer will be party to that

  • Bill_Toge

    Professional Chemist / Formulator
    January 17, 2017 at 8:02 am in reply to: TEA stearate manufacturing: odour/colour

    for my two penn’orth, I might add that in Europe, soap formation with sodium and potassium salts is exempt from REACh regulations - i.e. it is not ‘officially’ classified as a chemical reaction, and manufacturers don’t have to register their product with European Chemicals Agency if they make more than one ton per year

    however, this exemption does not cover TEA soaps; this is the main reason why many branders in Europe have moved away from them in recent times, and a likely reason for apparent discrepancies between European and US formulas for the same product

  • Bill_Toge

    Professional Chemist / Formulator
    January 13, 2017 at 12:17 am in reply to: Dipropylene glycol

    it’ll disperse just as well if you use a low HLB surfactant

  • Bill_Toge

    Professional Chemist / Formulator
    January 12, 2017 at 7:57 am in reply to: Dipropylene glycol

    if you want to solubilise a fragrance into oil, you need to use a low-HLB surfactant (e.g. oleth-3); polysorbates will not do the job effectively

  • Bill_Toge

    Professional Chemist / Formulator
    January 3, 2017 at 8:20 am in reply to: Silicones

    it’s a polysiloxane, i.e. it has a fundamental structure comprising multiple Si-O bonds

    the carbon equivalent would be a polyacetal, but due to the difference in chemistry between carbon and silicon it would be difficult, if not impossible, to synthesise such a compound and have it remain stable; silicon readily catenates (forms chains) with oxygen, while carbon does not

  • Bill_Toge

    Professional Chemist / Formulator
    January 2, 2017 at 7:30 pm in reply to: Need pointers for info

    2. not necessarily - if there’s not enough water in the formula to sustain microbial growth, the product can easily pass a challenge test without an active preservative (at my last place, this was our preferred method for preserving toothpastes)

    personally I’d describe that as “self-preserving” rather than “preservative free”, as it’s less ambiguous and less open to legal challenges

    3. that depends on your target market, and their attitude towards parabens - there is nothing intrinsically wrong with them, and plenty of evidence to show that they’re safe in finished products, they’ve just been maligned due to bad/misunderstood science

    plenty of major branders on this side of the Atlantic still use them, and it doesn’t harm their sales or their reputation

  • Bill_Toge

    Professional Chemist / Formulator
    January 1, 2017 at 4:34 pm in reply to: Mica pearlizer in Shampoo

    the aeration depends on the level of polymer used - when neutralised and back acid thickened, both polymers I mentioned are effective suspension agents at very low levels

  • Bill_Toge

    Professional Chemist / Formulator
    December 29, 2016 at 12:30 am in reply to: Mica pearlizer in Shampoo

    you need to include a surfactant-tolerant polymer to suspend particles in a product like this - in my experience, Carbopol Aqua SF-2 and Aculyn Excel do the job very well

  • Bill_Toge

    Professional Chemist / Formulator
    December 28, 2016 at 6:57 pm in reply to: How to Stabilize formulation with colloidal Gold Solution

    CMC is anionic, it won’t stay stable in the presence of cationic guar gum

  • Bill_Toge

    Professional Chemist / Formulator
    December 23, 2016 at 10:07 am in reply to: Should you trust the EWG?

    in my experience, safety assessors/toxicologists always cite the CIR and SCCS as primary sources for their safety data - not one of them cites the EWG

    to my mind, that really says it all

  • Bill_Toge

    Professional Chemist / Formulator
    December 22, 2016 at 11:47 pm in reply to: semi perm dye

    I both love and hate HC Blue No 15 (Jarocol Blue 15 / Arianor Jade Blue)

    I love it because it creates a striking and quite beautiful colour not achievable with most other safe / legal / effective / widely available blue dyes

    I hate it because it stains everything it touches with a vengeance, and it’s particularly difficult to shift

  • Bill_Toge

    Professional Chemist / Formulator
    December 14, 2016 at 8:00 am in reply to: Preserving unstable actives

    @MarkBroussard what kind of percentage would typically be used for this purpose?

  • Bill_Toge

    Professional Chemist / Formulator
    December 7, 2016 at 8:19 am in reply to: Preserving unstable actives

    it’s mostly oxygen from the air; if a solution containing a reducing agent is exposed to the air, it will draw the oxygen from the air, and if the solution has a low viscosity, any oxygen introduced into the product will rapidly diffuse through it

    perm lotions are a good example of this; the thioglycolic acid in the perm will readily pull the oxygen from the air, creating a pressure differential between the inside and the outside of the container, and if the head space is relatively large (e.g. if the container is partially filled) this causes the sides of the container to warp

    permanent dyes, which are usually high viscosity and non-Newtonian liquids, are also a good example, as oxidation in this case causes visible discoloration of the product; because the product is non-fluid, the rate of oxygen diffusion through the product is very slow/zero, and oxidation only occurs near any surfaces exposed to air

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