[Bill_Toge]

try Eurofins or Princeton Consumer Research - they routinely do this kind of test, costs are in the £3-4k ballpark

the latter are more expensive, but have a faster turnaround time

[Bill_Toge]

for what it’s worth, 1,2-diols and short-chain 1,3-diols (e.g. 1,3-propanediol) have antimicrobial effects at sufficiently high concentrations; the required concentration decreases as the carbon chain length increases

[Bill_Toge]

apropos of nothing, a few years ago Dettol sold a BAC-containing handwash based on cationic surfactants; I believe they used cetrimonium chloride as a primary surfactant and cocamide DEA as a thickener/foam booster, and the lack of decent alternatives made it difficult to replicate their product without treading on the toes of their patent

interestingly, the BAC in that product was above the maximum permitted limit for use in cosmetics as a preservative, so it’s very likely they were selling it as a human-use biocide

[Bill_Toge]

+1 for the Ajinomoto gelatinisers, they work in a huge variety of solvents

[Bill_Toge]

menthyl lactate also works very well

[Bill_Toge]

for sensory modifiers I’d also suggest checking out Agrana and AkzoNobel’s starch-based polymers

[Bill_Toge]

further to @ngarayeva001 the reason Cithrol 10GTIS works so well is that it’s self-dispersing (it has several bulky isostearate groups attached to the hydrophobic part) and also has a long hydrophilic section (PEG-20)

a similar effect can be achieved without PEGs by combining, e.g. polyglyceryl-3 polyricinolate as a dispersing agent with a hydrophilic emulsifier

[Bill_Toge]

you could use the powdered fruit

[Bill_Toge]

@Pharma if UV filters were were water-soluble they could very easily be washed off by, e.g. swimming

there are more advanced filters developed since the early 1990s, which are non-toxic and environmentally inert (e.g. bisoctrizole, bemotrizinol) and approved for use pretty much everywhere in the world apart from the USA

[Bill_Toge]

+1 for PEG-150 distearate being hard to work with; also, the viscosity it provides is extremely temperature-sensitive

[Bill_Toge]

speaking from bitter experience, IPA is a notoriously difficult solvent to thicken, as almost nothing polymeric can dissolve in it

[Bill_Toge]

we manufacture our own products and sell online, and demand has skyrocketed; while the office staff are isolated, the situation on the shop floor has gone absolutely mental, so we’ve had to recruit extra staff and extend working hours into a two-shift system

whether this will continue after everyone runs out of money and unemployment climbs to 30+ percent is another matter, but for now it’s all systems go

[Bill_Toge]

for what it’s worth, sodium pyrithione is VERY toxic; the reason zinc pyrithione is used in its place is because it’s much less soluble in water, hence less bioavailable

[Bill_Toge]

it takes a very long time to hydrate in water; if you want to speed up the process, use a high-shear mixer

[Bill_Toge]

MurtazaHakim said:

Is it appropriate to store Ethanol 99.9 % in IBCs or HDPE drums ???

I observed a company selling Ethanol 96% packed in HDPE drums which was to be used in perfumes Industries. 

yes, HDPE is extremely solvent-resistant

[Bill_Toge]

it turns your skin white (temporarily), and stings/numbs the area of application - not good qualities for a hand sanitiser

also, in Europe at least, hydrogen peroxide is restricted to specific types of product, and hand sanitisers are not one of those types

[Bill_Toge]

if you’ve got hydrogen peroxide in there, forget about trying to make a Carbopol-style gel - that stuff attacks and degrades even the hardiest of polymers

[Bill_Toge]

was it aerated to start with?

[Bill_Toge]

if you can get hold of Evonik Goldschmidt materials, try Tego Care PBS 6 (polyglyceryl-6 stearate / polyglyceryl-6 behenate) - it’s a remarkably robust and reliable PEG-free emulsifier, it even works with high concentrations of acids, salts or urea

[Bill_Toge]

try armed robbery

[Bill_Toge]

what’s the pH?

[Bill_Toge]

a vacuum pump can only do so much; the best way to avoid bubbles is to avoid introducing air into the product in the first place (prevention being better than cure)

[Bill_Toge]

yes: use more of it

[Bill_Toge]

for what it’s worth, aminomethyl propanol (AMP) is more soluble in alcohol, and forms more stable gels, than TEA

[Bill_Toge]

1,2-glycols are most effective antimicrobial glycols, followed by 1,3; depending which isomer you use, DPG is anything between a 1,5- and a 1,7-glycol, so I’d wager it’s much less effective than MPG