They were legally obliged to provide you with the MSDS on purchase. Should they not do so when you buy something new, to remind them they are breaking the law.
The MSDS for the Kilfrost TKS fluid is here
The one I had previously was Aeroshell Compound 07
The MSDS for Aeroshell Compound 07 (the original TKS fluid, referenced in many aircraft manuals) is here
Any opinions on which of the two above is less toxic?
toxic yes – but more or less only if swallowed. The following describes a wine scandal we had in Germany. Diethylene glycol was used as sweetener – at this time it was also used by Kilfrost for aircraft external deicing on the ground.
The 1985 diethylene glycol wine scandal involved a limited number of Austrian wineries that had illegally adulterated their wines using the toxic substance diethylene glycol (a primary ingredient in some brands of antifreeze) to make the wines appear sweeter and more full-bodied in the style of late harvest wines.1 Many of these Austrian wines were exported to Germany, some of them in bulk to be bottled at large-scale German bottling facilities. At these facilities, some Austrian wines were illegally blended into German wines by the importers, resulting in diethylene glycol ending up in some bulk-bottled German wines as well.2
The scandal was uncovered by German wine laboratories performing quality controls on wines sold in Germany, and immediately made headlines around the world. The affected wines were immediately withdrawn from the market. A number of people involved in the scandal were sentenced to prison or heavy fines in Austria and Germany. Although potentially health-damaging in larger quantities, no recorded instances of injuries from the consumption of the adulterated wines are known
Diethylene glycol (DEG) was otherwise used as an industrial chemical or as antifreeze, although ethylene glycol is more common for that application. Adulteration of products with diethylene glycol has led to thousands of deaths worldwide since the first recorded case: the Elixir sulfanilamide incident in 1937.5 Most of the recalled wines contained up to a few grams of DEG per litre (and many only a fraction of a gram), which meant that dozens of bottles would have to be consumed in a limited period of time to reach the lethal dose of approximately 40 grams. However, in one record-setting wine (a 1981 Welschriesling Beerenauslese from Burgenland) 48 grams per litre was detected, which meant that the consumption of a single bottle could have been lethal.
(source Wikipedia)
Very interesting!
The problem with TKS is that you will swallow some of the fluid, from the part of the system that does the prop or the front window.
However, unless I am missing something (I got only a Grade 6 O-Level in chemistry 
) neither of the two fluids contains DEG.
right, however they are very similar. DEG is a by-product producing ( Mono- ) Ethylene Glycol. Both taste sweet and both are used for de-icing/ anti-icing.
Found something interesting:
Ethylene glycol disrupts hydrogen bonding when dissolved in water. Pure ethylene glycol freezes at about −12 °C (10.4 °F), but when mixed with water, the mixture does not readily crystallize, and therefore the freezing point of the mixture is depressed. Specifically, a mixture of 60% ethylene glycol and 40% water freezes at −45 °C (−49 °F).2 Diethylene glycol behaves similarly. It is used as a de-icing fluid for windshields and aircraft. The antifreeze capabilities of ethylene glycol have made it a component of vitrification (anticrystallization) mixtures for low-temperature preservation of biological tissues and organs.
So if you get poisoned by MEG/ DEG the coroner will be very happy
Toxicity is also similar. Ethylene glycol is moderately toxic with an oral LDLo = 786 mg/kg for humans. Corresponds to 40g for DEG +/- 20%
If you read the sections of the MSDS on precautions and classification, neither of them are particularly hazardous. Don’t drink it (obvs), and wear gloves. If you spill it on yourself, wash it off. Nothing too nasty.
Understand dont drink the stuff, wear gloves when you handle it (I never do but should as I overfill the container and sop it up with paper towels) but what about breathing in the mist coming off the prop?
Precautions I take are closing all the vents. I even have a filter mask if I suspect it getting into the cabin. (Overkill Im sure)
I had to refuel the plane myself because I was mixing Prist in Denmark. Was told it’s company policy. Employees don’t go near it.
