Chlorine Bleach (and Peroxide)

From: Ted.Held at hstna.com on 2001.12.13 at 15:45:05(7901) Here are a few comments about chlorine bleach (sodium hypochlorite): -Nonpoisonous Relatively non poisonous - provided you don't acidify it (as by adding +More vinegar), which will release actual chlorine gas, a decidely toxic material. See later comments. -Compared to complex organics, less persistent True. But many of the commercial microbicides are actually not very persistent as was the case with early pesticides. I think current microbicides are good when used as directed. -Not absorbed by tissues (the prize plant or our skin and lungs) Will be absorbed by tissues as you might notice if you use bleach without gloves. That offensive (to me) smell that hangs on your exposed skin is evidence of lingering chlorine absorption (and tissue degradation). -Breaks down into water and ordinary salt Yes, once its oxidizing work is complete. -Even cheaper than hydrogen peroxide Pound for pound, bleach is less expensive than peroxide as a microbicide. On the other hand, we in the hobby are not in the business of mass killing where the cost is really a factor. Bleach happens to be handy, however, meaning that you have a disinfectant in the house whenever you need it. -Does not oxidize living tissue Does, in fact, oxidize living tissue. That is the way it kills. Bacteria and fungi are oxidized to death. It will oxidize your epidermis if not protected. Not advisable to leave it in contact with skin for any length of time. -As for friendly microorganisms, they can repopulate the sanitized areas very rapidly by spreading from the healthy surface of a tuber, or from healthy dirt True, provided the residual bleach is rinsed away and a healthy inoculate is available. -Very low concentrations will kill germs True. Bleach probably has ten times the killing power compared with an equivalent of peroxide. Incidently, will increase its killing power dramatically if the pH is lowered, making chlorine poison gas more readily available. Acidification by non-professionals is not advised. -You don't have to wear a respirator or chase away the kids and pets. Some people don't like the smell of bleach. I find it cloying and choking when used in a confined space. If you make a little dilution in a bucket for washing off tubers all you really need is a modicum of air circulation. If you acidify it, chlorine gas is really gross and can actually kill you. Take my word for it.

From: Ted.Held at hstna.com on 2001.12.13 at 15:45:45(7904) Oops. And when bleach breaks down there is also some residual alkali (sodium hydroxide, caustic soda) left over. This means the pH will be basic (probably 10 or thereabouts). +More ----- Forwarded by Ted Held/PA/Henkel Americas on 12/13/01 09:36 AM ----- Ted Held To: aroid-l@mobot.org 12/13/01 08:29 cc: AM Fax to: Subject: Chlorine Bleach (and Peroxide) (Document link: Ted Held) Here are a few comments about chlorine bleach (sodium hypochlorite): -Nonpoisonous Relatively non poisonous - provided you don't acidify it (as by adding vinegar), which will release actual chlorine gas, a decidely toxic material. See later comments. -Compared to complex organics, less persistent True. But many of the commercial microbicides are actually not very persistent as was the case with early pesticides. I think current microbicides are good when used as directed. -Not absorbed by tissues (the prize plant or our skin and lungs) Will be absorbed by tissues as you might notice if you use bleach without gloves. That offensive (to me) smell that hangs on your exposed skin is evidence of lingering chlorine absorption (and tissue degradation). -Breaks down into water and ordinary salt Yes, once its oxidizing work is complete. -Even cheaper than hydrogen peroxide Pound for pound, bleach is less expensive than peroxide as a microbicide. On the other hand, we in the hobby are not in the business of mass killing where the cost is really a factor. Bleach happens to be handy, however, meaning that you have a disinfectant in the house whenever you need it. -Does not oxidize living tissue Does, in fact, oxidize living tissue. That is the way it kills. Bacteria and fungi are oxidized to death. It will oxidize your epidermis if not protected. Not advisable to leave it in contact with skin for any length of time. -As for friendly microorganisms, they can repopulate the sanitized areas very rapidly by spreading from the healthy surface of a tuber, or from healthy dirt True, provided the residual bleach is rinsed away and a healthy inoculate is available. -Very low concentrations will kill germs True. Bleach probably has ten times the killing power compared with an equivalent of peroxide. Incidently, will increase its killing power dramatically if the pH is lowered, making chlorine poison gas more readily available. Acidification by non-professionals is not advised. -You don't have to wear a respirator or chase away the kids and pets. Some people don't like the smell of bleach. I find it cloying and choking when used in a confined space. If you make a little dilution in a bucket for washing off tubers all you really need is a modicum of air circulation. If you acidify it, chlorine gas is really gross and can actually kill you. Take my word for it.

From: Alektra at aol.com on 2001.12.16 at 22:08:44(7925) Nothing I have so far read about sodium hypochlorite, on this list or elsewhere, suggests that anyone has ever found it inappropriate to use for plants. I am going to go into more detail on my reasons for bringing up the question in the first place. Again, I repeat: Chlorine compounds such as sodium hypochlorite, calcium hypochlorite, and NaDCC are precisely what tissue culturists use to clean leaf-cuts and seeds. In fact, sodium dichloroisocyanurate can be used mixed into the medium, right into the substrate, to discourage microbial growth and safeguard the plant tissue! These people do not seem to find a raised final pH to be a problem. For the professionals among them, often there's a lot of money riding on the culturing. And naturally, people who culture tissue for a hobby would start demanding other disinfectants if they didn't like the results they get. If I were using one of these chlorine compounds on a rhizome or cutting or seed to plant or culture, I would rinse it afterwards, anyway. Maybe one of you out there who is culturing tissue at home could comment on this, or could ask the people on the various home tissue culturing lists, or at kitchenculturekit.com. I would think that those of you who are doing all that home tissue culturing to build up the santa-leopoldina species would know about this. Cost and availability are serious issues, I think. It is virtually impossible to get specific plant microbicides in small quantities at a reasonable cost. Specific plant microbicides are hard to get, impossible to mail order, and sold in expensive bottles or boxes that are enormous in relation to the size of a single dose. I get awfully skittish at the idea of, hypothetically, spending a work day taking a train out to the country to a farm store so I can spend twenty bucks on a liter of something just to get 5 or 10 ml, or a pound to get a fraction of an ounce. +More Furthermore, safety and disposal are even more serious issues. Supposing I got a quart of some specific plant microbicide and used the 5 or 10 ml I needed, I'd really hate to have the bottle around my place just getting stale and waiting to break, perhaps from an accident, perhaps from degeneration and pressure inside. But if I've got a quart of fungicide I need to get rid of, I can't flush it down the toilet the way I can with a quart of bleach or other chlorine compound. And if there were an accidental swallowing or eyesplash, I would =much= rather deal with nontoxic bleach (needing rinsing-- lavage-- and rest) than a specific microbicide (intravenous treatments). Speaking of toilet cleaning, I do not know about the educational background of this group, but I thought everybody knows not to mix vinegar, ammonia, or other acids with bleach. And nobody I am aware of has suggested vinegar or ammonia on plants anyway. There are lots of potentially dangerous chemicals that are commonly used at home, and I sincerely think bleach is a lot safer than, for example, old-fashioned brown Lysol, or TSP (trisodium phosphate), or even Tylenol. There's a certain amount of careful common sense that I think that we aroiders share. Sodium hypochlorite solution, at bleach concentrations or lower, does not oxidize one's epidermis when one leaves it in contact with the skin. The stratum corneum is a highly effective protective barrier. The lingering smell on the skin is not a sign of reaction with the epidermis. It is a sign that the stratum corneum has effectively blocked the bleach from going further. Speaking of aesthetic considerations such as smell, this really is a personal matter, insofar as some people actually don't mind it, go swimming in chlorine solutions daily, or put their private parts over toilet bowls that have water disinfected by chlorine tablets. Calcium hypochlorite and sodium dichloroisocyanurate are common pool compounds, and Chlorox sells tablets that are put into toilet tanks for slow release. And speaking of water, one last note about pH, especially, pH 10. My favorite bottled water, trinitysprings.com, has a pH of 9.6, and it tastes great. I h ave a cousin living out near that spring, and he doesn't have problems watering his lawn with this 9.6 water. Even four times as alkaline, pH 10, we're still not talking about the kind of alkalinity which would dissolve pieces of plants. So, to bring this topic back to where it started, is there anybody out there who can comment, from experience, on disinfecting rhizomes etc by using dilute solutions of various simple chlorine compounds? In a message dated 12/13/1 3:46:18 PM, Ted.Held@hstna.com writes: << Oops. And when bleach breaks down there is also some residual alkali (sodium hydroxide, caustic soda) left over. This means the pH will be basic (probably 10 or thereabouts). ----- Forwarded by Ted Held/PA/Henkel Americas on 12/13/01 09:36 AM ----- Ted Held To: aroid-l@mobot.org 12/13/01 08:29 cc: AM Fax to: Subject: Chlorine Bleach (and Peroxide) (Document link: Ted Held) Here are a few comments about chlorine bleach (sodium hypochlorite): -Nonpoisonous Relatively non poisonous - provided you don't acidify it (as by adding vinegar), which will release actual chlorine gas, a decidely toxic material. See later comments. -Compared to complex organics, less persistent True. But many of the commercial microbicides are actually not very persistent as was the case with early pesticides. I think current microbicides are good when used as directed. -Not absorbed by tissues (the prize plant or our skin and lungs) Will be absorbed by tissues as you might notice if you use bleach without gloves. That offensive (to me) smell that hangs on your exposed skin is evidence of lingering chlorine absorption (and tissue degradation). -Breaks down into water and ordinary salt Yes, once its oxidizing work is complete. -Even cheaper than hydrogen peroxide Pound for pound, bleach is less expensive than peroxide as a microbicide. On the other hand, we in the hobby are not in the business of mass killing where the cost is really a factor. Bleach happens to be handy, however, meaning that you have a disinfectant in the house whenever you need it. -Does not oxidize living tissue Does, in fact, oxidize living tissue. That is the way it kills. Bacteria and fungi are oxidized to death. It will oxidize your epidermis if not protected. Not advisable to leave it in contact with skin for any length of time. -As for friendly microorganisms, they can repopulate the sanitized areas very rapidly by spreading from the healthy surface of a tuber, or from healthy dirt True, provided the residual bleach is rinsed away and a healthy inoculate is available. -Very low concentrations will kill germs True. Bleach probably has ten times the killing power compared with an equivalent of peroxide. Incidently, will increase its killing power dramatically if the pH is lowered, making chlorine poison gas more readily available. Acidification by non-professionals is not advised. -You don't have to wear a respirator or chase away the kids and pets. Some people don't like the smell of bleach. I find it cloying and choking when used in a confined space. If you make a little dilution in a bucket for washing off tubers all you really need is a modicum of air circulation. If you acidify it, chlorine gas is really gross and can actually kill you. Take my word for it. >>

From: Mpclarkeyz at aol.com on 2001.12.17 at 19:51:56(7930) Hi all I hope you do not mind my chipping in, Marge is the member of this mailing list but I was the chemical engineer and worked for a company that made lots of sodium and calcium hypochlorites. Ted covered it pretty well but I have a couple of nit-picks. You do not get appreciably better biocidal action from chlorine than from hypochlorite. When chlorine dissolves in water it makes hypochlorite ion which does the killing. SO DO NOT ACIDIFY BLEACH SOLUTIONS!!!! As Ted says, it can kill you. The excess alkalinity in bleach solutions is caustic soda (NaOH), added to improve the shelf life. Without it shelf life would be days, not months. I'm not sure which is worse on your hands--hypochlorite or caustic. Be smart, wear rubber gloves. And one final, really nit picky, comment. The stink of bleach that remains on your hands if you don't wear rubber gloves is not chlorine, it is a mixture of chlorine oxides, and sometimes chloramines from the bleach attacking proteins. Since none of these are nice compounds, be smart, wear rubber gloves. Mac Clarke

From: Mpclarkeyz at aol.com on 2001.12.21 at 15:02:19(7972) Hi all I have no knowledge about using simple chlorine compounds on plants. I do have a friend who filled a tablet type pool chlorinator half full of calcium hypochlorite tablets, ran out ot them, and filled the top half with a chlorocyanurate compound (probably trichloro but it doesn't matter). He started the water flow and, fortunately, went back inside. While he was pouring himself a glass of water the pool chlorinator exploded and blew a foot or two of water out of the pool. Mixing water, hypochlorites, and chloroisocyanurates almost always causes an explosion, and people have been killed doing so. BEWARE!! Organic compounds should never be added to a container of calcium hypochlorite. READ THE STUPID LABEL!! Hypochlorites and chlorocyanurates are strong (in high concentrations often violent) oxidizing agents, and are very dangerous. So I get upset when people say "nontoxic bleach" or "But if I've got a quart of fungicide I need to get rid of, I can't flush it down the toilet the way I can with a quart of bleach or other chlorine compound." Please do not drink that non-toxic bleach nor dispose of it by pouring it down the drain. If you must dispose of it kill some weeds by pouring it on them, preferably in the sunshine which decomnposes these compounds quickly. Mac Clarke

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