Engine Coolant Safety
In my 135 Lehman the engine coolant (Ethylene Glycol) circulates through a
heat exchanger in the water heater - as in many vessels. Since EG is toxic
might there be a chance that a leak in the heat exchanger could contaminate
the potable water supply? (This assumes that the pressure on the coolant side
of the exchanger is greater than the pressure on the water side.) If the risk
is real then why not replace the EG with nontoxic polyethylene glycol (the
pink stuff)? I have not seen this discussed on the list. What say you all?
Steve Anderson
"Intrepid" 42 Krogen
-----Original Message-----
.......Since EG is toxic
might there be a chance that a leak in the heat exchanger could
contaminate
the potable water supply?
Steve,
Yes, that is a very real risk, although with the dilution involved, I don't
know how severe it is.
Two years ago I started losing coolant on my main. For every hour of
operation, I was losing about 2 ounces of coolant. Yep, as you've already
guessed, it was leaking into the hot water heater! I took the two hot water
hoses off the heater and bypassed it until I could replace it.
Does anyone know how severe the health risks are of getting EG into the
potable water? Thankfully, I use bottled water for drinking and cooking,
and only used the domestic water for cleaning.
Kevin
Kidney failure for one, automotive antifreeze is highly toxic. How much
does it take I don't know but animals (pets) that lick an antifreeze puddle
(probably 50/50% mix) usually experience kidney failure.
That is a byproduct(risk) of engine coolant loop through the potable water
heater system I hadn't thought of. Frightening thought.
Joe
Carolyn Ann GH N-37
Snip:"...Does anyone know how severe the health risks are of getting EG into
the
potable water? Thankfully, I use bottled water for drinking and cooking,
and only used the domestic water for cleaning...."
Of course consider the domestic water is under a far greater pressure then
the engine coolant. I would think any leakage would be small and quickly
tasted, I would think before any health risk. Bill
----- Original Message -----
From: "Joseph Pica" joseph.pica@gmail.com
To: trawlers-and-trawlering@lists.samurai.com
Sent: Wednesday, January 06, 2010 1:56 PM
Subject: T&T: Engine Coolant Safety thru Hot water heater
Kidney failure for one, automotive antifreeze is highly toxic. How much
"Steve Anderson" stevena48@earthlink.net writes:
In my 135 Lehman the engine coolant (Ethylene Glycol) circulates through a
heat exchanger in the water heater - as in many vessels. Since EG is toxic
might there be a chance that a leak in the heat exchanger could contaminate
the potable water supply? (This assumes that the pressure on the coolant
side
of the exchanger is greater than the pressure on the water side.) If the
risk
is real then why not replace the EG with nontoxic polyethylene glycol (the
pink stuff)? I have not seen this discussed on the list. What say you all?
Several responses:
First, ethylene glycol is HIGHLY toxic. The fatal dose is about 100 ml in
adults (that's about a half-cup). This is not something you want to take
chances with (http://www.antizol.com/egpoisono.htm).
Second, all heat exchangers used in the application of ethylene glycol <->
potable water should be "double wall" (also called "dual wall") type. These
heat exchangers have a small air gap between the tubes, and that gap is open
to the outside of the case. Even if there is a leak within either one of the
sides (fresh or coolant) the resulting leak will flow out of the heat
exchange instead of mixing with the other side. Check the specs of your hot
water tank to confirm this, some older tanks may not be built this way.
Third, yes, there is antifreeze based on propylene glycol. PG is non-toxic
when it's pure, but PG antifreeze is still toxic due to the additives
(http://en.wikipedia.org/wiki/Antifreeze#Propylene_glycol).
Fourth, both propylene glycol and ethylene glycol are sugars and hence have a
distinctive sweet taste. If your potable water EVER tastes sweet, INVESTIGATE
IMMEDIATLY.
This is one area where you don't want to mess around.
Scott Welch
"Things turn out best for people who make the best of the way things turn
out." - John Wooden
I guess there is a chance but if it was a small leak, I don't think it would
get to a toxic level. If it was a large leak I think you would notice the
problem in the Lehman long before your liver. I also think you'd taste it
in your potable at any concentration that posed a human risk. It would also
likely be a short term exposure.
EG is biodegradable and as I recall, the toxicity risk was higher for
animals that might drink it (like a dog bowl)
Jim, amateur toxicologist.
As a side note: I once did an EG cleanup for the Navy (Air)....neat
project....they had a leak in a cooling lagoon for a test engine...they were
working on having less heat signature in their airplane exhausts (obvious
reasons). Got to see the blimp hangars where the Hindenburg went up on that
project! That was a very early biodegradation project.
----- Original Message -----
From: "Steve Anderson" stevena48@earthlink.net
To: "T&T E-mail" trawlers-and-trawlering@lists.samurai.com
Sent: Wednesday, January 06, 2010 12:40 PM
Subject: T&T: Engine Coolant Safety
In my 135 Lehman the engine coolant (Ethylene Glycol) circulates through a
heat exchanger in the water heater - as in many vessels. Since EG is
toxic
might there be a chance that a leak in the heat exchanger could
contaminate
the potable water supply? (This assumes that the pressure on the coolant
side
of the exchanger is greater than the pressure on the water side.) If the
risk
is real then why not replace the EG with nontoxic polyethylene glycol (the
pink stuff)? I have not seen this discussed on the list. What say you
all?