SailNet Community - Reply to Topic
Thread: EG vs PG--If marine toxicty is equivalent, why not use EG for non-potable systems? Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

  Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below

  Topic Review (Newest First)
01-06-2013 01:44 PM
EG vs PG--If marine toxicty is equivalent, why not use EG for non-potable systems?

First, I'm not talking about potable water systems. PG is much less toxic to mammals than EG. That is well established, so let us skip that discussion. Black water and engine systems only.

Let's avoid cost discussions. They are in fact very, very close, with EG generally cheaper. PG antifreeze typically apears cheaper because the -50 burst stuff only contains 25% PG.


Why does it matter?
* I've been doing some immersion testing of marine parts in PG and EG and the results for PG are not pretty. Neoprene gets hard. Nylon crazes.
* I have spoken with a number of respected marine mechanics who unanimously agree that PG ruins neoprene water pump impellers.
* These problems are also well known in the automotive engine coolant industry, perhaps the secondary reason all OEMs avoid using PG (primary is that is an inferior heat transfer and antifreeze agent).

So I did a little reseach that I posted here:
Sail Delmarva: EG vs PG: Conventional Wisdom That is Provably Wrong
In a nutshell, I could find no credible data that sugested any important difference.

From Risk World (European conference)
"Based upon the limited available data, no general distinction can be made between aquatic toxicities of ethylene and propylene glycol formulations."

I have also contacted a number of environmental agencies and groups that post PG recomendations on-line. Of course, none had done any research of their own. Their answers are variations on:
* We got our information from (another site with no data).
* "Everyone knows...."
* Liability concerns. Someone will use EG in the potable system.
* "We are concerned about heavy metals" (While there are heavy metals in used vehical engine coolant, that is not a EG/PG difference).


Does anyone have data regarding EG/PG and marine toxicity that tells a different story? Is there some other reason?

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

For the best viewing experience please update your browser to Google Chrome