Prist when and with what to use it

[Pace]

Hate the stuff especially in pressure tins! Many fuellers wont go near and even had one who refused to fuel even with me doing the Cans.
Some fuel has additive yet a fueler stated his fuel was good to -47 and didnt contain additive?
Do those who need to use Prist use it in summertime on low level trips or just high in V cold conditions?
There is a poring variety which sounds better?

Pace

[Agaricus bisporus]

Why on earth do you need to use it? Why isn't the fuel you buy up to spec?
Are you sure H & S allows you to handle it? I wonder.

A simple internet search will reveal how it is packaged and why the delivery pipe needs to be clipped to the fuel nozzle (which is no doubt also clearly explained on the can) which should answer your "poring" (sic) question.

You don't carry this stuff around on the aircraft, do you? How do you manage when fuelling away from base?

[Cecco]

We use Prist once a month because it´s a good precaution against bacteria growth in the fuel tank (citation cj1+), no matter at what altitude you are flying or at what season. Water freezing in fuel is a thing of the past with
the fuel-to-oil heat exchanger.

Cecco

Min.Fuel Temp. according our AFM: -30 Celsius

[JonDyer]

1. It's not an anti fuel-icing additive - it's an anti-water additive. The fuel is quite possibly good to -47ºC but the water that's disolved in it, isn't.

2. It's not particularly nasty stuff. You don't want to be drinking too much of it, and I understand that it should not be used as an eye wash, but you won't die if you do either.

It is carried on 525s routinely - even the 525A. One of the fuel companies did have a standing instruction for a while not to allow it during refueling but I've never been refused.

[Agaricus bisporus]

Ah! Now I've been stung into reading Prist's webiste all is clearer.

My recollection of using the stuff (large company) was that we treated it as though it was highly toxic even by skin contact.

Interesting too that I see no mention of use as a bug killer on the manufacturer's website, or did I miss it?

[Uncle Wiggily]

I know the Learjet 35 ops manual recommends using Prist. Will the plane fly OK w/o it...99%...sure. But there was a crash several years ago relating to the icing up of fuel and Lear then said that you should use a can for every x amount of gallons pumped into the aircraft.

Obviously, there are other aircraft that still use it, but I know the older Learjets definately purchase the little cans of the stuff.

[JonDyer]

The CJs with heat exchangers are still required to use a Biocide (I don't have the reference in front of me, but it's in the AFM) that'll be the 525A and it seems the 1+ and I assume the 2+ and the 3.

The CJs without heat exchangers use it for both fuel biocide and to soak up water.

One of the major problems with it is that if it is not adequately homogenised with the fuel it can clump and those clumps can then block the same filters it was introduced to keep clear.

This problem used to occur on the EBJ fleet with some regularity because we used to use the pouring cans rather than the aerosols.

[Pace]

I know it kills all the bugs living in the fuel tanks who have a taste for gourmet Jet A1 but am concerned about its cancer inducing chracteristics?

The Cans are notoriously unreliable and the dispensing caps even more so.
Pouring with rain you have to stand outside with the refueler finger firmly pressed on the dispensing button for what seems like an eternity.

I use surgical rubber gloves but even then some cans blow back when attaching so you have to look away while attaching the nozzle.

I believe refuelers are stopped by H and S from handling the stuff yet we do.
This is on a Citation 2 and while used most of the time there can be an occasion when the cans dont work or you dont have it.

I was interested as to when its vital to use Prist or when you can get away without? or use lower amounts than recommended?
Plus getting fed up getting soaked (by rain :) every time we refuel. The co has a habit of vanishing at refuel times.

Pace

[matoto]

The only important thing is what it wrote in Pilot Operanting Handbook.

Depenting of aircraft oil/heat exchanger is not enough to ensure safe operation.
(See crash of Boeing 777 at heathrow few years ago.)

Last september, we don't put Prist in tank (lack of time :ugh: ) Fuel Temp on Ground 15°C, Total Fuel Quantity nearly 2600 Lbs. After two hours at FL260 , OAT-30°C, both fuel pump came "on" and fuel filter by-pass pop out.
30 minutes later we were safe on ground and only during taxi, Fuel pump came "off".

[supermoix]

As stated before, Prist is a glycol based liquid that works magic preventing water dissolved in fuel to freeze up in ice crystals and block filters. IMO Not much different than wing anti-ice. Prist does not advertise themselves as a anti-fungal/anti-microbial additive. Bio-Bor is the product used to kill living things inside fuel tanks.

Old generation citation I and II's to needed Prist as a regular basis to avoid this same problem, and some pilots i know still use it in Beechjets, i think they do not have fuel heaters.

Just as a note, The citation Bravo, due to a good Oil to Fuel heat exchanger do not need that stuff, but not long ago i had a "FUEL GAUGE" light in the master warning panel, indicating an error on the fuel gauging system, possibly caused by long term fuel contamination. the option to fix it was defueling the airplane, opening the wet wing and change on one the offending capacitor probes (read expensive). An old mechanic told me to try first putting pre-mixed Prist in Jet-A at any airport that offers it and monitor... You know what? the fuel gauge problem went away in just five flights and has not recurred agin in two years, so I found another use to Prist.

Regarding the toxicity and cancer potential, I think is no worse that some airport food I've had to eat in some long days...

[cldrvr]

Hmm, interesting discussion here. My question is as "prist" is an aerosol and classified as UN1950, do all these Citations have dangerous goods licenses to carry this on board?

This is a quote from the Prist website:

Health Risk Rating: Harmful
Health Hazards

Acute— Diethylene glycol monomethyl ether (DEGMME), the primary ingredient of Prist Hi-Flash aviation fuel additive, is an eye and mucous membrane irritant, a nephrotoxin and central nervous system depressant.
DEGMME can be absorbed through skin in toxic amounts when contact is extensive and prolonged; it is toxic by skin absorption. And it may cause pain and transient injury to eyes. DEGMME may cause irritation to the mucous membranes. Due to the low volatility of this material, it is believed to present no unusual hazards from inhalation when handled at room temperature. The oral toxicity of DEGMME is low.http://www.pristaerospace.com/hi-flash/safety/index.html

From their own data sheet:

HANDLING
Isolate from oxidizers, heat, sparks, electric equipment & open flame.
Use only with adequate ventilation. Avoid breathing of vapor or spray mist.
Do not get in eyes, on skin or clothing.
Wear OSHA Standard goggles or face shield. Consult Safety Equipment Supplier.
Wear gloves, apron & footwear impervious to this material. Wash clothing
before reuse.
Avoid free fall of liquid. Ground containers when transferring. Do not flame
cut, saw, drill, braze, or weld. Empty container very hazardous! Continue
all label precautions!I have never seen a Citation Jockey on the ramp with an apron and goggles on...



Furthermore, the HSE states referring to UN 1950:
TRAINING all modes of transport
Appropriate training for consignors of dangerous goods is required, the 1 day BAMA Transport of Aerosols course is suitable training and certificates are issuedBAMA Fact Sheet - Transport of Aerosols by road, sea & rail - British Aerosol Manufacturers' Association (BAMA) (http://www.bama.co.uk/transport_factsheet/)

[Boeing man]

This brings back memories when I operated citation 500 and 550 back in early 90s we used prist 100% of time we always had a case stored in front lockers .later on ce 650 no requirement to use it.

[Pace]

Hmm, interesting discussion here. My question is as "prist" is an aerosol and classified as UN1950, do all these Citations have dangerous goods licenses to carry this on board?

We carry the stuff and no dangerous goods but makes disturbing reading. Know there is a pouring alternative which seems more secure to use although not sure of the difference or mixing ability?

Pace

[cldrvr]

Prist is a UN 1950 with risk R12, that makes it subclass 2.1 if I am right. Anyone got an updated Dangerous Goods manual handy? I am not sure if it is even allowed to be carried on passenger aircraft or is that one limited quantity only? Google is a bit ambiguous on that one.

Anyone with the right reference?

[Check 6]

Anti-ice additive (Prist, Dice, etc.) is REQUIRED in Lear 20 and 30 series aircraft. This is not a "recommendation," it is a limitation as spelled out in the AFM.

It is also required in the Pilatus PC-12.

[leadingedge12]

A lot of the fuel you put into your aircraft has prist premixed already. It is a required additive on many aircraft clearly stated in the limitations section and yes it is hazmat that shouldn't be carried on board passenger aircraft. So when you are operating to a remote location are you going to bring the cans of prist or operate out of limitations?

[firefish]

If the manual says use it then use it. Dual engine flame out is more harmful than the potential danger of pouring prist in the fuel.

And as stated, it is not about lowering the freezing point of the fuel but rather to make sure that the water in the fuel doesn't cause problems. Some engines have good fuel heaters, some have fuel filter de-icing capabilities (like the RR Viper) and some need additives.

If you are uncomfortable about using these additives you can sometimes get fuel with the stuff already in it (like Shell Aerojet). You can't get it everywhere but it is a way of lessen the exposure.

[Pace]

Lots of useful info. We have to carry the stuff I have yet to find a supply away from base without getting some from another Pilot / aircraft.
Spray cans are a potential hazard especially with a product as dangerous as this.
The instant pour variety has to be better? We realistically have to carry Prist but would be interesting to know the CAAs view on carriage and dispensing by Pilots.
Maybe rubber gloves, goggles and a mask should be a must as how many of us really knew how dangerous this stuff really is and have not handled it safely?

Pace

[His dudeness]

One outfit I flew for had a permit to carry prist (IIRC 3 tins).

Some fuel trucks can tank with prist mixed in, happens somewhere near the pump. Thankful we havent got to use that stuff anymore.

[inbalance]

German LBA published a letter how to tranport Prist in limited Quantities:

http://www.lba.de/cae/servlet/contentblob/33778/publicationFile/1109/B32_antiicing.pdf

[tommoutrie]

Jonny Dyer.. you've turned into Yoda!

[Agaricus bisporus]

Well, seems my memory wasn't so far wrong after all.
Its a toxic hazchem that can't legally be carried in an aircraft without a dangerous goods licence, however it is a certification requirement to use it on certain types.
You need to have done a course before you touch it and must wear a face mask or goggles, and impervious gloves, apron footware which must be washed before re-use.
The manufacturer states categorically that it MUST not be merely poured into a tank as this is more hazardous (to the aircraft) than not using it at all yet regular users seem unaware of this!
Other users seem to think it has further properties unknown to the manufacturer (ie biocide).
Users evidently ignore the health hazards mentioned above and carry - and use - it illegally and to the potential detriment of both their own health, and that of their pax.
"Justifying" illegal use and carriage is no different from claiming that you "have" to bust minima because the company expects you to and the pax "must" get to their destination.

I'm rather shocked at the cavalier attitude shown to H & S at work and hazardous goods carriage by both employers and users (pilots) here. If you get poisoned by this stuff there's only one person to blame, and it ain't your employer!

[JonDyer]

Feeling I had, you'd turn up to a discussion on Prist, Moutrie Tom.

Was going to mention your extensive research - but I judged you'd arrive to tell us yourself!


Other users seem to think it has further properties unknown to the manufacturer (ie biocide).

The C25A AFN contains a statement from Cessna that DIEGME additive (e.g. PRIST) has provided acceptable protection from bacterial growth in fuel systems.


I have no idea whether the manufacturers are aware of Cessna's position on this - but I suspect that they probably are.

Edit

I just checked the PRIST (http://www.pristaerospace.com/hi-flash/FAQ/index.html#biocidal) website myself and of course they do acknowledge that their product has these properties - they just point out that the certification process is uneconomical so they haven't completed it.

[cldrvr]

Before we start throwing insults at each other, does anyone here have the rule book to hand and can verify for the non fuel heater carrying jockeys what the carry limitations are on UN1950 subclass 2.1?

Once we know the facts you can pass judgement to your heart's content.

I'm rather shocked at the cavalier attitude shown to H & S at work and hazardous goods carriage by both employers and users (pilots) here

[JonDyer]

I checked the Dow Chemicals datasheet for Diethylene Glycol Monomethyl Ether, and it says nothing to confirm the (apparently widely held) view amongst pilots and refuelers that this is a deadly neuro-toxin similar to Sarin.

Just to be clear - this stuff is not made to be eaten. Neither is Jet A1, the aircraft itself, or your uniform.

The data sheet says the following about handling it: (my underlining)

Health Information
Eye contact with DEGME may cause slight temporary eye irritation and/or pain disproportionate to the level of irritation to the eye. Prolonged skin exposure is not likely to cause significant irritation or result in absorption of harmful amounts.

No adverse effects are anticipated from single exposure to DEGME vapor. Small amounts swallowed incidentally as a result of normal handling operations are not likely to cause injury due to its low toxicity.
Dow do not make Prist (they make DICE) - apparently Prist make Prist themselves. So I checked their datasheet to see how they advise handling it. (my underlining again)

After mentioning gloves and goggles they say this:

Boots, aprons, or chemical suits should be used when necessary to prevent skin contact
So what have we got?
It's an irritant - it hurts a lot when it gets in your eye but it doesn't do any lasting damage.
It's not likely that a pilot can suffer sufficient skin exposure to allow for any negative effects,
It's biodegradeable and it's effective as a biostat but noone wants to pay the certification costs that would enable it to be advertised as such.They also say that if you want to go out on the apron wearing a full chemical-warfare attack prevention suit and a geiger counter then you can be their guest.

I'm going to stick to goggles and gloves myself.

[falconer1]

to the original question about whether to use Prist or not to....

Guess, one can say, if it is required for your aircraft as per AFM / POH, then you have to use it..

but be advised that that is for pure fuel anti-ice reasons..

Any angi-fungal properties are not only highly in doubt..

PRIST themselves do not claim that anymore on their web-site ( and not because it would have been inconvenient or complex to certify it for that use..)

on the contrary, relying on PRIST, TOGETHER with bad fuel tank draining practices can create enormous problems..

called "apple jelly", that stuff is known to have sent FCUs south, engines have stopped or behaved erratically..

So draining the tanks everytime is of utmost importance..

even if the plane does not fly...planes "make water" in the tanks just by the temp diff between night & day..

Questions & Answers: Prist Hi-Flash (http://www.pristaerospace.com/hi-flash/FAQ/index.html)

http://swri.org/4org/d03/fuellube/petprod/images/03-4371.pdf

[MAN777]

Used Prist for years, as a previous poster has said it is not as dangerous as some would have us believe, there seems to be a self perpetuating myth emanating from the fuelers which is not backed up by fact and which suits their self obsessed Health and safety cultures that they have surrounded themselves in.

Yes its certainly not the sort of stuff you want splashing around and a degree of common sense should be used when handling it but you should not be frightened of using it.

For prist to work correctly it has to be dissolved or held in suspension in the fuel, aerosols work best sprayed directly into fuel flow. If you spray aerosols directly into standing fuel it just sinks to the bottom as does pouring prist. Pouring prist is designed to fill tanks that supply an agitation system that mixes fuel and prist in measured quantities,these systems can be found on fuel bowsers. Pouring prist should not be poured directly into aircraft fuel tanks it wont mix, sinks to the bottom and forms a jelly like mess in the tank.

Basically prist works by attracting water particles held in suspension in the fuel, it forms larger clumps which sink into the water catch sump, once there it can be safely drained off. It is not an anti freeze it is basically a water collector.

[Steak&Kidney_Pie]

DIGEME as many on here state, lowers the freezing point of the (very small amounts of) water in the fuel. It used to be advertised as a Biocide, but now the manufacturers of the said brands have admitted that it is too expensive to certify. If they don’t hold approval, then they will not advertise the property of DIEGME. Remember they are in America, the home of litigation. :mad: Speak to them directly on the phone and they will admit off the record this claim. It does hold bio-cidal properties.

Application of an “additive” will be declared in the AFM. If it is declared, then follow it. In the event of an insurance related incident, then this could bite you if this was not followed. I would far rather have to use the product than suffer engine flameout(s). :ugh:

The pourable cans can present massive problems. The primary reason is people chuck them in, in their entirety, and then begin fuelling. The rate of mixing is vital. If it is not mixed properly, then “apple jelly” will form in the tank. This then gets sucked into the system and it will not burn. It can also therefore clog the fuel filter. On several Citations, I have been involved with un-commanded engine rollback due to clogging, (in the Hydro-mechanical fuel unit of the C550) as well as “fuel filter bypass” annunciations. :{ The answer is daily checking of fuel drains when flying. :ok:

The D-ICE product produced in aerosol cans works far better. The only real issue with this is the fact the aerosol propellant could be dangerous if handled without care (exposed to piercing, excessive heat etc.) Also care is required when inserting the nozzle to avoid squirting in your eye. When using it, turn the nozzle away from yourself and the fueller.

All types must be handled with care and common sense, (unfortunately the latter being a dying attribute:ugh::mad:) All operators I have worked for have provided eye protection and gloves. If not, buy some. It is your choice what you choose to use and whether you choose to use it. :confused:

JohnDyer: your comments are quite accurate! And very sensible. :ok::ok:

It is vital that when DIEGME is used in the fuel, that aircraft fuel drains are drained daily. You will collect the orangey coloured apple jelly at some point.

Cessna states directly:
“In addition, to checking water in sump drains, proper blending of fuel products such as Prist® and biocide additives is equally important to monitor. Too much Prist® in poorly blended fuel can sometimes cause an “apple gel” condition to form in fuel tanks. Should an improper mixture ratio of anti-ice and biocide additives be discovered, the airplane must be defueled and then returned to service. Refer to the Chapter 12, Fuel –Servicing procedures in the applicable maintenance manual.”

An important fact to note here, is that if the aircraft is left for an extended time period, and/or is subject to large variations in temperature, then the DIEGME can come out of the fuel and settle to the bottom of the tank which can be drained off during the next pre-flight inspection. (Related to the comments made by falconer1 and MAN777:ok:)

There are refuellers at certain airports, which can over-react with the appearance from the nose locker, of fuel additive. They are taught (for some unknown reason that it is carcinogenic) and therefore you have to refuel yourself. Airports I can remember doing this at are Copenhagen, Stockholm and Exeter. Go to the product websites, learn the information, and help sensibly educate the refuellers. :cool: I have found this has worked wonders with some airports we regularly visit.

As for airports with pre-mix, they tend in the UK to only be military, although Shell at Bournemouth provide the facility as do TAG refueling at Farnborough.

Please note under EU-OPS:
"Airworthiness and Operational Items (OPS 1.1160(b))
An approval is not required for dangerous goods which are required to be aboard the aircraft such as:
(a) Items for airworthiness or operating reasons"

This proves there is no issue carrying these products. ;) You can carry them onboard in a nose-locker. Many operators have done this for some 30 years now.

As you may or may not be able to tell, I have had to do a risk assessment on this before and researched it. (Still using it BTW!) :mad::ok:

S&KP

[FlyingGasMain]

Lots of good info here for those who have to use Prist regularly eg. drivers of the older Citations. I've used the pour-in cans before and poured it in at the same time as the fuel, but not tried to moderate the flow much, so I've learnt something. The cans do come with a pouring nozzle but its a pretty crude way of controlling the flow compared to the aerosols.

Anybody able to name other airport/fuel company combinations (UK or European) where pre-mix fuel is available ?

FGM