Chlorine tablets or, How I nearly killed me (and maybe "us"))

I'm posting this for those that either have the Galley Maid waste treatment systems or who use chlorine tablets for any purpose in the boat's water system.

THIS IS REALLY IMPORTANT!!! ONLY use chlorine tablets that are Calcium (or Sodium) Hypochlorite. DO NOT USE chlorine tabs that are Trichloro-s-triazinetrione (Tri-Chlor) or Sodium Dichloro-s-triazinetrione (Di-Chlor). The only thing to really remember is ONLY Calcium Hypochlorite since Sodium Hypochlorite tablets are not as commonly available as they used to be. If you are using swimming pool tabs in your intake strainers, make sure they are Calcium Hypochlorite. Regular toilet bowl tabs should be fine but I don't know that for sure. If they are sodium or calcium hypo they are OK.

Galley Maid says to use only Calcium Hypochlorite tabs in the system (previously it was Sodium Hypochlorite but calcium is more widely available and they changed to that some years ago)

That's the important part. Here's the (long) story. You can save yourself a lot of time by just following the advice above and not bothering with what follows. But it is a good example of how I screwed up badly without realizing it.

I have the GM waste treatment system. In NY I used sodium hypochlorite tabs. No problem at all - it was the original tablet recommended by GM when the systems were developed. Later, they changed the recommendation to calcium hypochlorite.

We moved here and I could not find Sodium hypo tablets so back in '07, at the local hardware store, I found Calcium hypo tabs. I bought a container on the calcium hypo shelf...

Shortly afterward I started having strange problems - the SS fasteners holding the GM container (star eng room) with the tabs would literally disintegrate in a matter of a few months with a brown, almost oily substance on them. Aluminum was showing some oxidation while the same parts in the other eng room were not. Also, the braided hoses connecting to the tablet container were turning white up near the container fittings (these are the standard clear braided hoses with the red-ish strands of fiber mesh). There was always the smell of chlorine in the eng room. It's important to note that the container for the tabs does not have an airtight seal, it's just a cover which slides down over it.

I called GM, they told me that that reaction was caused by mixing different chlorine tabs or using the wrong chlorine tabs. I ASSumed that they were referring to the difference between Sodium, which I used to use, and Calcium, which I THOUGHT I was using. They said no, the problem was most likely caused by someone using the wrong tablets previously. They said that it should clear up rapidly and again emphasized that I should be using Calcium Hypo as per the current GM instructions. I figured they were idiots and didn't know what they were talking about. I was right but had the wrong "idiot."

The same thing was happening in the master stateroom where the GM tab container is located under the starboard cabinetry. You could detect the odor of chlorine in there just as in the eng room and the SS hose clamps were failing. Keep in mind that all this has been going on for a couple of years.

OK, flash forward to yesterday eve. All day I had been nursing a severe headache that I couldn't shake - I had awakened with it after having slept the night with the Master stateroom door closed and all the ports closed. In addition to the headache, I had a cough, a bit of wheezing, my throat was a bit sore and my eyes were a bit burny. Figured I was getting sick or it was allergies. I took some Ibuprofen for the headache per recommendations of a famous physician I had lunch with. I didn't mention the other symptoms.

I worked all day in the star eng room (GM container in there) and the headache/other symptoms seemed to be getting worse and worse. I had seen that the GM container strap was again in need of replacement so I opened the container and literally gagged from the fumes, racing out on the deck for air. I have a toxic chemical mask (for Imron and such) so I put that on, went back in the eng room, put the cover back on the container, and turned on the blowers.

I determined to call GM again in the morning. But as I thought about it, dimly a light went on (in my head, not a real light). I knew from the previous conversation that they would just say to use exactly what I (thought) I was using. So I began to wonder why, since the system USED to work fine with the recommended chemical and now with the new recommended chemical, it wasn't. Smugly, I figured "I know this is not necessary but as a first step I'll go through the motions and check the container of chlorine tabs." I had not the slightest concern it could be wrong, it was just a box to be checked. I looked at the ingredients and almost fell over - TRI CHLOR!!!

I looked it up - it reacts with (destroys) some metals and plastics. Obviously, SS is one of the metals and braided hose contains one of the plastics. Then I looked up symptoms of chlorine exposure:

?They include:
? wheezing, ?sore throat, cough, eye irritation (and stuff a whole lot worse). Well, well, well.... ;)

For whatever chemical reason, which I don't know (or care) the Trichlor tabs react to produce a lot of fumes where the Sodium Hypo (and I assume, the Calcium Hypo) does not. As I said earlier, with sodium H, there was no chlorine odor in the boat and even opening the container produced no more than the smell of opening a bottle of clorox.

So this morning I opened both containers, removed the Tri Chlor tabs, washed down the containers with soapy water and am running fans aimed at both. I will change out the hoses, the deteriorated SS fittings (hose clamps and screws that mount the containers to the bulkheads), purchase some CALCIUM HYPOCHLORITE and start over.

USE ONLY CALCIUM HYPOCHLORITE and check the container a couple of time before you walk out of the store.

What I did reminds me of the story of the guy on LI who disconnected his CO sensor because it kept going off but he couldn't smell anything. He and his family died of CO poisoning.

Mike,
Thanks for a valuable message.
Regards,

Here's a pic of braided hose that was passing the tri chlor/water mix. The white was so brittle that if you hit it with a hammer it broke. This hose was new last year. This hose does not pass sewage, just the water/chlorine. You don't want tri-chlor/water going through any hoses so that's why I suggest that if you use pool chlorine tablets in your strainers, you check to be sure it's not tri chlor or di chlor.

http://i208.photobucket.com/albums/b...6/DSC_1268.jpg

Chlorine poisoning....and I missed it? maybe it's time to retire..glad you aren't dead. I had no idea.

Like most patients, I lie to doctors! ;)

So user error? Glad you were lucky and didn't end up a Darwin Award candidate. It's pretty freaky how many average chemcials can kill you super fast, but of course some states ban ammo and don't let 17 year olds by sudafed.

Yes, absolutely user error! I knew what I wanted, checked the label, then a few minutes later went back to that shelf and grabbed of bucket of tablets but this time I didn't look at the label, not noticing that the two different chemicals were side by side. They also have different color tops - Calcium Hypo has a yellow lid, Trichlor a orange lid. Didn't notice that when I was looking at the labels.

Nobody did anything wrong but me! :(

The "other" tab chemicals you mention cannot even be used in the skimmers of swimming pools...they are so STRONG that the plastic skimmers and container basket become brittle.....and fail.

Sodium hypcochlorite is, by the way, household bleach...about 5% chemical, 95% water....

It does destroy the white sewage hose! I just got back to the boat - opened the eng room door and now, without the chlorine smell to mask it, I could detect the odor of waste in the eng room. The new (last year) white sewage hose from the outlet of the GM macerator to the waste treatment system was sticky to the touch and my hand smelled strongly of poop. Oh Poop! Another set of hoses to change due to my screwup. ;)

Mike- glad you're feeling better and back on track. I have to admit thought, I did giggle at your latest post- I thought you were going to say that your hand smelled of lavender!

Cheryl & Mike