So...who uses Excel? (Gluteraldehyde)

thank you to mr batten for taking the time to respond our discussion here on TASA it is much appreciated by all i'm sure.i cannot comment on the scientific aspect of this i will leave it to professor dirk and other knowledgable members,i would like to know if possible can you catergorically state that using seachem excel in the prescribed doses has absolutely no harmful affects on fish at all and that this has been tested?

 

Or can anyone categorically state that using it in the prescribe doses does cause harm to fish?

 

i think this is where we're having the problem and i think the best people to tell us would be seachem themselves as they would be the ones to have tested it.

 

Thank you George. (And welcome to our forum as well...)

Your explanation, whilst at times very cumbersome to read through if you are not a chemist, or understand basic science, seems to have shed some light.

In South Africa we have 9 official languages, (or is it 11 guys? I forget). I would go as far as saying our membership contingent is approximately 48% English, 48% Afrikaans, and 4% something else. Of the 48% English speaking, probably half of that did science in English medium... so we can take a guess that 24% of the members here would have an idea of what you explained, or at least recall this type of "atomic" discussion being shared in class.

So guys, before we all charge Seachem with additional questions that are probably already answered, I've requested @Dirk Bellstedt if he wouldn't mind popping in here again at his earliest convenience, to give us a basic run-down and explanation of what George has shared. Dirk will possibly also ask for additional information, so please keep popping in.

Remember: "You heard it first on TASA!!"

 

@oscar freak Exactly!My reply is not ment to argue your statement but its just if they come back and say NO we cant sate that it doesnt harm fish as we havent tested it then Im going to be left wondering if that means it does harm fish or if they just havent tested it Argh haha. Damn thread. Cause as ive said my fish and as do many other people fishs dont show any ill signs at all.

 

@Zoom, Haha you are a champion thank you! I was busy scratching my head and trying to remember stuff from matric science 14 odd years ago! Needless to say my head is now sore.

 

i know CharlieB neither am i i'm simply saying we have all this info going around thats causing the confusion.what we'd like to know i think is what has seachems tests proven.

 

@oscar freak, exactly. lets hope they can get back to us with some test results.

 

Yes, I can state that at the specified dose, there is no observable harmful effect on fish. You may want to consult an interesting review paper in the journal Ecotoxicology and Environmental Safety, volume 49 issue 1, published in May of 2001 (pages 26-39). The title of the paper is "Ecotoxicology of Glutaraldehyde: Review of Environmental Fate and Effects Studies," by Hon-Wing Leung at Union Carbide. You may object to his affiliation, but at least the paper passed the peer-review process. Since it was a review paper, it dealt with a fair number of studies performed by others. The key in this paper is the NOEC (No Observable Effect Concentration), a level where absolutely no effect was seen. The Flourish Excel dose stays below the NOEC level for fish. That isn't true for certain estuary species (Calanoid copepods and some oysters, for example) but Flourish Excel is designed for planted tanks, not salt water tanks. Leung's review also indicates there is very little tendency to bioaccumulate, that it is biodegradable in a freshwater environment, and that the metabolism of the material takes two different routes, depending upon whether it is done so under aerobic (to carbon dioxide) or anaerobic (to 1,5 pentanediol) conditions.

 

Forgive my manners in my previous post and welcome to tasa.by now I"m sure you've gathered our objective here is merely to find out if your product which is widely used by some of tasa's I think its in excess of 2000 members is safe for not just fishkeeping but also fish breeding.now when you say no noticable harm is noticed are you referring to external physical signs and or death?what of internal damage of fish?you say there is no bioaccumalation,is this in the aquarium or the fish?thanks again for your time.

 

good point @oscar freak i also think that there should be some toxicology report or test recorded to prove the inhabitants of the trial or test tanks in question had no ill effects with long term exposure to this product.

 

I am referring to no external physical signs and no increase in death rate compared to control groups. There may be some studies in the scientific literature that report results of necropsies but we do not do those here on a regular basis. Bioaccumulation, as I understand the use of the term, generally refers to the environment, meaning that the biodegradability prevents a buildup of glutaraldehyde in a sludge, for example. (It is a reducing agent, and tends to be consumed as it reduces other compounds.) I will note, however, a line in Leung's paper as follows: "The toxicity of glutaraldehyde to aquatic organisms is not appreciably increased with repeated long-term exposures." (That is from page 37.) That is not a definitive statement regarding bioaccumulation in an organism, but it can be read positively.

 

I apologize for posting these things in what must appear to be a random order. This is for Firemanmuzz. See page 37 of the Leung paper above for the following statement: "The toxicity of glutaraldehyde to aquatic organisms is not appreciably increased with repeated long-term exposures." This of course refers to repeated exposure at low levels, below the no observable effect concentration.

 

If a person smokes a pack of cigarettes a day for 10 years there will be "no external physical signs and no increase in death rate compared to control groups". However, we all know that if you cut them open and had a look at their lungs it would not be pretty. Saying there are no external physical signs does not prove that there is no internal damage and that their lifespan is not shortened.

 

Once again thank you mr batten for your time and input we don't often have this oppurtunity.

 

For Jenn, true enough, if a person smokes a pack a day for 10 years there will likely be no increase in the death rate compared to control groups. Ornamental fresh water fish do not live for 70 or 80 years, as humans do. Their life spans are short enough so that we have studied these effects over the entire life span of the fish, not just 12 to 14% of their life spans. And, to proceed with the analogy you have introduced, we have had solid scientific evidence dating back to at least 1964 (the first time I was made aware of it) indicating that smoking shortens the life span of a human. When I search the scientific literature, I do not find comparable data for the effects of low doses of glutaraldehyde on fish.

 

Dear Dr Batten,

Thank you for your reply. You are obviously responding to questions that I asked about Excel as a result of which I would like to respond. However, I do not wish this to become an argument about you claiming one fact and I claiming another, this would not be constructive. I would like to state some aspects from my perspective, you would obviously be welcome to respond and then I feel that the aquarist must decide whether he wants to use Excel or not, it is his/her decision.

May I firstly say that I fully agree about its benefits and where it fits into the metabolism of plants, you would see that I have given a similar argument about its benefits before, so I fully agree about the benefits that this substance can have for plant growth. South African aquarists are also all agreed that Excel is very useful against algae, and I also do not doubt that. These are therefore clear benefits of using Excel, I do not doubt those.

However, in spite of your reply, there is still a considerable amount of uncertainty in my mind about the safety of the use of glutaraldehyde.

You have in your post, clearly indicated that exposure to glutaraldehyde is dangerous to the user, you personally use gloves when working with it, and you appear to have developed a sensitivity towards it. A simple internet search would get numerous hits about the dangers of glutaraldehyde exposure to humans. It has been used in medical science because of it can be used as a very effective chemical to sterilize medical equipment, in other words it kills microbes, but this has exposed many humans to its detrimental effects and for this reason, a considerable amount has been written about the dangers of glutaraldehyde. I will be the first to admit that this is at higher doses than what you recommend should be added to an aquarium, but numerous publications list its dangers, and many of these are in the USA. As an example, I refer the reader to: http://www.cdc.gov/niosh/topics/glutaraldehyde/

You quote safety sources in California and in this internet reference there is a reference again to the "California Department of Public Health: Glutaraldehyde Fact Sheet

" see http://www.cdph.ca.gov/programs/hesis/Documents/glutaral.pdf​

In that fact sheet from California its states, and I quote:

"Cancer: Whether glutaraldehyde can cause cancer in humans has not been studied. It does not cause genetic mutations in most laboratory tests. This suggests that it is unlikely to cause cancer. However, it is closely related to the cancer-causing chemical formaldehyde. Glutaraldehyde is now being tested to see whether it causes cancer in animals that breathe its vapor."

So you state that there is no evidence that it causes cancer, but here we read that it has not been studied. So we cannot actually make the statement that it does not cause cancer, at this stage we do not know. You state in your post that the difference between methanol and ethanol is significant and that it can be compared to the differences between glutaraldehyde and formaldehyde. In South Africa we have many methanol drinkers as opposed to ethanol drinkers and are acutely aware of the differences between these two alchohols. However, I do not agree with your comparison of glutaraldehyde with formaldehyde. Just look at the quote above from the California Department of Public Health which states that glutaraldehyde is closely related to formaldehyde. If your authority in California states this, am I wrong in saying that they are similar? If they are similar, and this document states that formaldehyde causes cancer, how can we categorically say that it does not cause cancer if glutaraldehyde is similar to formaldehyde? This question remains unanswered.

I agree with you that the glutaraldehyde levels in Excel and the recommended doses for its use in aquaria are low, but in spite of this, I have my concerns about its use in aquaria.

In my post, I asked the question:

Have you made any anatomical analyses of fishes before and after extended treatment with Excel?

You have not answered this question, and I want to ask you this again. Until this has been done by an independent laboratory, there is no scientific evidence that this product is safe for use in aquaria in which fishes are kept in my opinion.

In conclusion, I would like to state that I would not like this to turn into an unpleasant accusation session, I appreciate it that Dr Batten has personally replied. My personal reservations about the product will remain, but anyone is free to decide whether they want to use the product. Seachem produce excellent products, the use of which I support (see the seachem discus buffer thread), but I have my personal reservations about the safety of the use of glutaraldehyde in aquariums, and I hope that the persons that have responded to this thread can respect my opinion, you are entitled to yours, and so is Dr Batten and Seachem, you must decide if you want to use it.

Kind regards,

Dirk

 

I think what we can categorically state on this thread is that we will never all agree on this topic, and the decision will rest with each aquarist whether they want to use it or not. I think we could talk this thread over and over, and we would continually be going around in circles and circles. The danger is now, (and we've seen it from time to time), the "mob mentality" may re-arise... derailing this thread entirely again.

I think in summary, we can conclude:

Seachem Excel admit to the use of Gluteradehyde in their product. The dangers if it is known, however based on third party, research the dilution they use is below levels that is considered safe. It would be interesting to read the type of research and study that this third party did in order to ascertain this conclusion.

Dirk Bellstedt has stated his scientific opinion based on his vast knowledge in biochemistry. His opinion is that regardless of the dilution of gluteradehyde, the scientific evidence against the chemical is still not safe in his mind, and he has given his own reasons as to why he believes this.

The decision ultimately rests with you, the member. A debate is just that... giving the facts from two opposing sides of the fence, and allowing the audience to make up their own mind.

I am going to leave this thread open for now, however, sadly, I am expecting a few members to "have there say," and use this platform as a personal attacking position, rather than constructive criticism. Please note that the moderators will remove such posts, and I have actually advised the other moderators that we should consider closing this thread in a few days time.


To Dr Batten, and Michael from Seachem;
I would like to extend a really big thank you on behalf of all the members here as Tropical Aquarium for your input in this thread, as well as the Discus Buffer thread. The moderating and Administrative team would also like to extend an additional invitation to sign up as a sponsor, I know our members would greatly benefit from your presence, ultimately growing the extremely fast growing aquarium industry in South Africa.

Regards

 

@Zoom, Very well said and thanks to all parties involved for their knowledge and for helping us better understand this product! I doubt there is a single person who hasnt at least learnt a little from this epic debate!

 

Hear, hear!