Talk:Median lethal dose

From Wikipedia, the free encyclopedia
Jump to: navigation, search

LD50 of H2O[edit]

As I stated in my edit summary, the reference doesn't state an exact number. It may be that they were unable to produce a statistically significant result in testing, or it may be that they were unable to kill any rats at all even at extreme levels--though that's really just speculation and doesn't belong in the main article. Anyway, is it useful to keep this questionable number in the table? Preferably, a better source should be found, but the typical chemical companies I use don't have that number in their MSDSs. Also putting "check" tag on the number. 128.138.64.70 (talk) 17:53, 4 June 2009 (UTC)

POV?[edit]

This article seems to be slanted towards the animal rights movement, e.g. putting "controversy" at the top, and the only links pointing to "Animal Testing" and "Vivisection" (which in its own right is a fairly pejorative term). LD50 is a value arrived at through animal testing, true, but if this article is to be considered the norm then all drug pages should have links to "the horrors of vivisection"...62.56.126.163 20:48, 15 October 2006 (UTC)

Yeah, the animal rights section should probably go after the basic concepts, and I hate 'controversy' sections - there's almost always a better title. Hopefully it's a little better now, though it could still do with external links on other angles of this topic. --Calair 16:53, 16 October 2006 (UTC)

The references relative to the sentence in the introductory part: "In 2011 the U.S. [...] as they relate to humans." do not provide any scientific evidence of lack of reliability in animal testing. For this reason the part of the sentence declaring:"[...] in response to research, cruelty concerns, and the lack of validity and sensitivity of animal tests as they relate to humans" must be removed. --AL458 (talk) 20:20, 26 September 2012 (UTC)

Should LD50's of substances be given in Wikipedia?[edit]

There is at least one drug (fentanyl) for which the wikipedia entry has LD50 info. Agreed, recreational fentanyl users are usually hardcore types (I was one, in the early 1980s!). But there are so many OTC medications or easy-to-get-a-prescription-for medications for which the LD50 is much lower than what laypersons think, otherwise there would be lots more successful suicide attempts. Which don't occur because most people with suicidal feelings think that "if you can kill yorself relatively painlessly with something, it must be hard to get".)

Putting LD50 information on Wikipedia pages would be good, as wikipedia is an encyclopedia, although i think it would be necessary to add a small warning somewhere on page where the LD50 is included that they should not solely depend on this information and especially not if they intend to use it as a 'rubric' for consumption. --Neur0X .talk 00:46, 15 July 2006 (UTC)
I think listing LD50 data for substances would be appropriate, but only if we're careful about verifiability and qualification. LD50 values always depend on several qualifiers - mode of administration, subject species, and (very often) an extrapolation from animal results to humans, for instance. It often has political implications, and even without those, it's human nature to pick the most most impressive (i.e. most lethal) possible interpretation of the data. IMHO, LD50 data should only be presented if it states the relevant measurement circumstances and is directly supported by an appropriate source. --Calair 07:00, 17 July 2006 (UTC)

I have seen that almost all blokes on the usenet [incl rec.drugs.hard] are responsible enuff not to give out this info. Ditto for the web. I hope that wikipedians also will refrain from providing LD info for substances not-too-hard-to-get. I dont think that info belongs to a general-purpose encyclopedia (or, indeed, to any easy-to-access source).

23:53, 4 Jan 2005 (UTC)mp from Calcutta India

looking up LD50's on a substance requires 2 things, knowing what a MSDS is and knowing the chemical name or the chemical composition of a drug. Neither of these are hard to come by. I don't think LD50's should be listed on wikipedia, not because people would use it to commit suicide, but because Wikipedia is not a Chemical info warehouse. There are ALOT of compounds, naming them all I believe are outside the scope of this site, let alone provide detailed information. Maybe wikifoundation could setup a WikiMSDS site or something... (MSDS stands for Material Safety Data Sheet, which usually contains the LD50 dosage, but this is changing as LD50 is being phased out because of animal cruelty) --ORBIT 04:49, 16 Feb 2005 (UTC)

if we have an article on a chemical known for it's toxicity then we should include the LD50 (cyanide arsnic and the like). If not then it probably isn't relvant.Geni 18:17, 25 May 2005 (UTC)

IMO there should be a list of most toxic (eg. botulin) and least toxic materials (carbon, water...) and their LD50 values (if applicable)... As for the dangers of listing them, well, quick Googling can probably find them anyways. - G3, 16:08, 14 February 2006 (UTC)

Dangers or no dangers, Wikipedia has no responsibility to nanny people. We don't need to care if people could try to kill themselves with this information, simply because most people won't. The fact that shooting yourself in the head is rather deadly isn't exactly privileged information either. --217.91.122.24 (talk) 08:28, 18 June 2008 (UTC)

Removed text[edit]

I removed this passage from the introduction:

Two species are normally required to be involved in the testing. A feeding syringe is forced down the animals’ throats, injecting into the stomach a chemical ingredient of the product, or the product itself, often household cleaners or gardening products like weedkillers. The forced feeding increases in amount until half the animals are dead, after experiencing vomiting and convulsions. Technicians note quantity required to kill 50% of the animals, and then the survivors are killed. No harmful effects are measured, just the lethal dose.

I did so because as it stood it was misleading; its position in the introductory section gives readers to understand that this description applies to all LD50 testing, which it certainly does not. For one thing, the methodology described would only provide a LD50 for ingestion - this might be useful for evaluating toxicity of a consumer product, but not for investigating (e.g.) a snake venom or an injected/inhaled anaesthetic. For another, while many toxins will cause vomiting and convulsions, this isn't universal. And whether harmful effects are measured depends very much on the researchers in question.

This material might be elsewhere in the article, if accompanied by information providing some context on just whose experimental process it's describing, but it doesn't belong in the intro. --Calair 03:14, 18 October 2005 (UTC)


I'm also quite concerned about the POV of the removed statement. I'm not exactly an encyclopaediac source, but it seems a bit fallacious to claim that household cleaners and weedkillers are 'often' used, without some sort of citation. I also doubt the claim presented as fact that they experience vomiting and convulsions, as my gut feeling tells me this cannot be the case all the time. 80.7.199.165 16:16, 10 March 2007 (UTC)

In the Limitation section, the sentence: "Another weakness is that it measures acute toxicity only (as opposed to chronic toxicity at lower doses), and does not take into account toxic effects that do not result in death but are nonetheless serious (e.g., brain damage)." is a mere nonsense, as LD50 test is not aimed to measure nonlethal toxicity in specific organs. It should be removed.--AL458 (talk) 20:34, 26 September 2012 (UTC)

What when LD-50 information is wrong or misleading...[edit]

The LD-50 given for Acetaminophen/Paracetamol is from rat tests and is nearly 2 grams per Kg, yet folks routinely commit suicide with doses under 25 grams. In fact the UK doesn't allow supermarkets to sell more than 16 tablets at a time because of the suicide risk. The gap between reality and the posted LD-50 should be addressed. — Preceding unsigned comment added by Dr Wagstaff (talkcontribs) 21:47, 10 May 2012 (UTC)


The LD-50 given for fentanyl is 3.1 mg/kg. The dosage administered by one of those duragesic fentanyl patches, total (since this is what the patch contains) is between 2.5 mg and 10 mg. This is administered over 48-72 hours.

Only people who are opioid tolerant are supposed to get the 75 ug/hour and the 100 ug/hour strengths of the patches.

Now, one might presume that an adult would weigh at least 40 kilograms, so a 10 mg dose would be an eighth of a mg/kg/day. And yet that dosage can still be fatal.

I know of one case where an abuser had to be taken to the hospital because of respratory depression after consuming 10 mg in a single dose. He was normal sized and not completely narcotics naive.

I know the point is not to promote recreational drug use, and I know that there are other issues, but someone trying to size a dose might die in short order at 10th the listed LD-50, and probably would at 1/2 the listed LD-50.

Simicich 00:16, 1 November 2005 (UTC)

This isn't really the place to ask such a question, try the reference desk. But you understanding of LD50 appears flawed. A dose significantly below the LD50 isn't necessarily a safe dose. The LD50 is simply the dose at which 50% of the test population dies. Clearly some will die at a lower dose, they don't all suddenly die when given the LD50. Depending on the substance in question, people's reactions could vary significantly.
Also your calculations are incorrect. If a 40kg individual received 10 mg, that's 1/4 or 0.25mg/kg. If the LD50 is 3mg/kg, this will be about 1/10 of the LD50 and I don't think anyone would suggest this would be a safe dose or a good idea without further information. I definitely don't think anyone in their right mind would suggest 1/2 of the LD50 could be considered a safe dose...
Finally, remember the LD50 is the LD50 in whatever animal was used for testing. Just because the LD50 is 3mg/kg in rats or whatever, doesn't mean it'll be the same in humans. Also, remember it's important to consider the method if administration. If you're talking about the oral LD50, then using this for patches which administer subdermally I assume is a very bad idea. The LD50 is arguably a useful measure to have but they aren't an end all and it's important to understand what they are. In your case, I would suggest the Lowest published lethal dose or LDLo is a more useful figure to consider.
Nil Einne 10:31, 21 December 2006 (UTC)

Plutonium[edit]

Removed this text: Similarly, in the case of certain metalic elements, plutonium in particular, the LD50 is properly expressed as µg/kg, or even as nanograms/kg. About 1 µg of plutonium, if inhaled, is presumed to be probably a lethal dose, in the long term, because it is known that it will promote and almost guarantee lung cancer.

As per discussion on plutonium, there is a lot of dubious information about plutonium toxicity doing the rounds without citing any good sources; AFAICT, a lot of it ultimately seems to have come from Heinlein's fiction story The Long Watch.

This article estimates the cancer risk from inhaling 1 µg of reactor-grade plutonium dust at around 1/200 (for Pu-239, around 1/1300) and cites several other sources that yield similar numbers. Markedly lower numbers need to be supported with citations. --Calair 04:11, 3 November 2005 (UTC)

OK; but I doubt you'd be willing to inhale some plutonium dust. Or would you? Show us all how brave you are.  :)

Depends. How much is 'some'? --Calair 00:55, 4 November 2005 (UTC)

I recall a Dr Cohen (probably Samuel, probably not the same Cohen) who proposed building an extremely radioactive wall, or trench, around Israel. It would kill anyone who went near it, to defend that country against its enemies. I hadn't read too many ideas that were crazier than that one. He was a scientist. I believe he worked at Los Alamos. It made me think of Dr Edward Teller and his insane idea, that the world could survive even a full-scale thermonuclear war; no problem.

I'm inclined to believe that *some* pro-nuclear scientists (like scientists who work for the food, drug or tobacco industry, or really any field where there is money to be made) have agendas that can make their scientific judgement suspect.

This is one of the reasons why we don't take science on trust. Scientists are expected to show how they got their results, so other scientists can examine their reasoning and attempt to reproduce the data that supports it. It doesn't entirely eliminate the problem of vested interest, but it goes a long way to reduce it; this is why controversial claims need citations. --Calair 00:55, 4 November 2005 (UTC)

For example. In the 1950's, one of the Atomic Energy Commission's top scientists began promoting the term "sunshine unit", to describe exposure to nucleotides and radiation. Like it was no more worrisome than getting a suntan. We all know that by the 1960's, fallout had become such a serious problem that it led to the end of above-ground nuclear testing.

However: point taken. I accept your edit. It was really a point about *units*, anyway. I gave plutonium as an example. Thanks for your explanation, but I don't think you need to reach as far as SCIENCE FICTION to express your objection. lol -- Stellar-TO

Come on, that image is horrible.Improfane 01:16, 1 January 2006 (UTC)


LCt50[edit]

It is usually expressed in terms of mg-min/m³ or ppm

I removed 'ppm' because the units don't match - ppm is a concentration, whereas LCt50 is a concentration * time. This may have been a typo for ppm*min, but I don't know for sure. Will also change 'usually' to 'often' since I don't know whether mg-min/m^3 qualifies as 'usually' without this second unit. --Calair 03:14, 1 January 2006 (UTC)

Database for LD50 values[edit]

Is there a general database for all (almost all?) known LD50 values for all tested chemicals? -Samulili 10:26, 16 April 2006 (UTC)

Some MSDSes will contain that information, and I think the Merck Index might also contain LD50/LC50 values for a wide range of chemicals. I don't know of a specific LD50 database, though. --Calair 01:18, 18 April 2006 (UTC)

Semilethal dose[edit]

Removed semilethal dose from the intro, I work with chemicals and haven't heard the term "semilethal dose" being used for LD50. It is also very misleading as it is a fully lethal dose for 50% of the population, while semilethal could be read as sublethal. Dictionary.com for example uses the term "median lethal dose" which is more accurate. Sad mouse 00:24, 20 June 2006 (UTC)

It's not the most common term, but Googling finds quite a few hits that aren't just mirrors of Wikipedia; searching PubMed for 'semilethal dose' found five hits, e.g. "The effect of intravenous endotoxin (Sal. abortus equi) in a semilethal dose in rats was very individual"[1] & "Total number of red blood cells, their acid resistance, deformability and fragmentation were studied in rats after intramuscular injection of a semilethal dose of viper poison" [2].
Searching Pubmed gives 18625 references for LD50, of the 5 references in Pubmed for semilethal dose three (including the one you cite) are non-English papers, and the other two referred to the genetic term semilethal and not to LD50s. Sad mouse 01:09, 20 June 2006 (UTC)
However, note that the genetic usage has a very similar meaning: a mutation that causes at least 50% mortality. --Calair 03:37, 20 June 2006 (UTC)
The genetic usage is not really similar at all. Regardless, the point remains that Pubmed references use "median lethal dose" not "semilethal dose"
"Sufficient to cause 50% mortality" is pretty similar, IMHO. --Calair 05:33, 20 June 2006 (UTC)
Actually semilethal can be used in genetics for a gene which is lethal sometimes, but not always, and does not have to be 50% of the time [3]. Anyway, not a big deal, the current wording is fine, personally I wouldn't even bother to qualify with the "non-English speaking" part. Sad mouse 17:24, 20 June 2006 (UTC)
Furthermore, a google search gives 76,200 results for "median lethal dose", 2,470,000 for LD50 and only 773 for "semilethal dose". Of those 773 hits, most (488) appear to just contain the phrase "LD50 or colloquially semilethal dose", others are actually referring to a sublethal dose (ie, a dose at which none die, such as 164 hits referring to the radiation references). Sad mouse 01:32, 20 June 2006 (UTC)
Can you point me at some of the articles that use it to mean a sublethal dose? I've come across several that use it in connection to radiation, but all that I've checked seem to be using it to mean LD50. For instance, US Patent #5008199 refers first to "X rays at a dose of 630 rad almost corresponding to the LD50" and then to "a semilethal dose of 630 rad". (The same patent also refers to a "semilethal dose" of an injected substance.)
I don't have time to look this up, it is a minor correction that I made. This reference for example uses semilethal where it means sublethal [4]. And again, google has very few references for semilethal and lots of median lethal dose.Sad mouse 04:23, 20 June 2006 (UTC)
I am not contesting the fact that 'median lethal dose' is far more commonly used than 'semilethal', only the contention that 'semilethal' is not used. --Calair 05:33, 20 June 2006 (UTC)
Other examples:
Website on Hiroshima Day: "It is said that 50% of persons who receive a whole body dose of 400 rad, which is known as a semi-lethal dose die, and that those exposed to whole body radiation of 700 rad or more have little chance of escaping death... The location that was exposed to the lethal dose of 700 rad was a point approximately 925 meters away from the hypocentre (in Hiroshima); and in the case of the semilethal dose of 400 rad, ap­proximately 1,025 meters."
'The trigger to cell death determines the efficiency with which dying cells are cleared by neighbours', Cell Death and Differentiation, July 2001: "...we examined engulfment following death induction with DNA damage-dependent and -independent stimuli. Etoposide induces apoptosis as a consequence of DNA damage, whereas the kinase inhibitor staurosporine induces programmed cell death even in anucleate cells. 293 cells exposed to a semilethal dose of etoposide for 48 h exhibited a more than 10-fold increase in phagocytes (cells containing one or more phagosomes) compared to controls..." This one doesn't specifically identify it with LD50, but since it's certainly not talking about a sublethal dose - the whole point is to kill cells - that's presumably what they mean.
I'm certainly not claiming that it is a common usage, but it is out there. It does seem to be the case that it mostly (not always) appears as a result of translation from non-English originals but I don't see that that makes a difference; if it's used in publications intended for an English-speaking audience, then that's a usage that should be acknowledge. --Calair 03:37, 20 June 2006 (UTC)
So we leave in the sentence saying it is another term, and try to clarify, like my edit did, yes?Sad mouse 04:23, 20 June 2006 (UTC)
I agree that 'semilethal' is ambiguous, but then that's why Semilethal dose redirects here, to a page which removes the ambiguity. Given that it is used elsewhere, better that we explain it than not. --Calair 00:36, 20 June 2006 (UTC)
Then maybe the intro could say that it is sometimes referred to as a semilethal dose, but this term is misleading. The reason I clicked on LD50 was because the feature article today inferred the amount of thujone in absinthe was safe because it was below the LD50, whereas that is only evidence that less than half the population would be killed by it. Misleading, I think you'll agree. Sad mouse 01:09, 20 June 2006 (UTC)
No, it didn't. It inferred that it was safe because it was much below the LD50; while that's not a completely cast-iron conclusion, it's far more reasonable than it would be without that 'much'. --Calair 03:37, 20 June 2006 (UTC)
Actually it is a completely usage conclusion, because an LD50 says nothing about the dose at which 10% of the population dies, for example. Anyway, are we happy with how it currently is written? Sad mouse 04:23, 20 June 2006 (UTC)
While knowing LD50 doesn't give us an exact figure for LD10, it gives us a great deal more than nothing - both a hard upper bound (LD10 can't be more than LD50) and a fair bit of probabilistic information beyond that. While variability of effects is different from one substance to another, it's not enough so to stop us from concluding that the LD10 is unlikely to be greater than 0.95x or less than 0.001x the LD50.
I think there are some problems with the discussion there (will tackle that over on absinthe if I get the time) but they look to be more to do with chronic vs. acute exposure issues than with the issue of variability of effect.
I'm quite happy for the article to deprecate 'semilethal dose'; I have some quibbles over the wording (it's not clear to me that 'semilethal' is a particularly misleading term for something that's lethal to half a population) but IMHO, the main thing that needs fixing is that the definition should go first. Will edit accordingly; see what you think. --Calair 05:33, 20 June 2006 (UTC)
  • Are you using median as in statistics? Does it apply to LD50?
  • The PubMed usage might be that they took it from abstracts written by non-native English speakers.
Thus, I would stick with the usage and definition by MeSH while you consult with the staff of the NLM about the correct term. For the sake of full disclosure I'm not a user of LD50 but I have deleted another mistaken definition that equated it to half-life. Jclerman 01:27, 20 June 2006 (UTC)
Yes, as in statistics, which is how LD50 is determined. As above, the term semilethal dose is not used in a single English-language articles in Pubmed to refer to LD50, while >500 articles use "median lethal dose" to refer to LD50. In light of the google search, semilethal dose should probably be taken out completely, it doesn't seem to be used.Sad mouse 01:38, 20 June 2006 (UTC)
Note that PubMed searches only pick up words contained in the abstract; the Cell Death & Differentiation paper I mentioned above, for instance, is indexed in PubMed but doesn't show up on a search for 'semilethal'. That paper is in English, written by five UK-based scientists and published by a UK-based journal, which IMHO is reasonable evidence that 'semilethal' is indeed used, albeit infrequently. --Calair 03:37, 20 June 2006 (UTC)

Added LD50 template[edit]

since it seems rather tedious to write out LD50 in it's html/wikified form, I made a template in which when you wish to say LD50 you simply type {{LD50}}--Neur0X .talk 00:40, 15 July 2006 (UTC)

ED50[edit]

The official standardized method to measure the LD50 is described well under the OECD-methods 401, 402 and 403. The LD50 is a statistical value obtained on biological material. Consequently it has mostly a broad standard deviation.

It might be an idea to mention the ED50 (Effictive dose, 50%) in here as well. This is the amount of a substance that gives the desired therapeutic effect. If these are in same page the LD50/ED50 ratio should also be mentioned, it is a good indicator of how easy it is to take an accidental overdose.

"LD50"-values in human.[edit]

One faces often an confusing (confused) values of LD50 in humans. For instance:
"LD50 of batrachotoxin: estimated at 1 to 2 µg/kg in humans."
Now, it is certainly possible to extrapolate some biochemical/toxicological research values to get an "estimated LD50 in human", but is it of any worth? Moreover, often the "LD50" dose is beeing unintentionally interchanged with the lethal/fatal dose in human (so often exaggerated use of specific expert terms by general public or media, sometimes even inappropriate use of these terms by an expert). That is, f.e., from the information, that a 300 mg dose of potassium cyanide ingested killed an 75 kg individual, is concluded, that the "oral LD50 in human" is 4 mg/kg. I think, that it is not right to mention an LD50 dose in human, unless it is really found out by an LD50-experiment (which is, beside some Nazi crimes during WW2, almost certainly not), because: a) it is almost never plausible enough precise, because not based on realistic, controlled experiments; b) it is of no practical value; even if an LD50 value for a specific chemical/poison was known, it would have no effect on medical and/or forensic aspect of the toxicity of substance/poisoning by substance; in most poisonings, intensive/specific medical care is needed even if LD10, LD1 or LDLo are ingested/resorbed. On the other hand, even a LD99 dose must not be inevitably lethal in an individual. I would suggest the more appropriate and rational use of terms "estimated LD in human" (which could be anything from LD10 to LD99), or "LDLo".--84.163.109.162 12:12, 27 March 2007 (UTC)

I think the answer here is to enforce Wikipedia:Verifiability. If we have a reliable source that lists a human LD50 figure, we can cite it (although it would be good to indicate how that figure is derived - I agree that extrapolated values are very unreliable). If we don't have a citeable source, the claim shouldn't be in the article. --Calair 12:43, 27 March 2007 (UTC)


I agree; however, I still think that the use of "estimated human LD" is more appropriate, reality-close and relevant.--84.163.109.162 12:55, 27 March 2007 (UTC)


I agree too, but we need some exact values. Why have there been NO controlled LD50 experiments in humans? Someone should perform one sometime. --Whoop whoop pull up (talk) 15:17, 3 October 2010 (UTC)

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 16:29, 10 November 2007 (UTC)

Toxicology Task Force[edit]

Just wanted to announce the creation of a new Toxicology Task Force under WikiProject Medicine. Feel free to come and sign up. Thanks -- Jrtayloriv (talk) 04:06, 3 February 2010 (UTC)

Removed line[edit]

LD50 still remains popular, despite its general weakness in providing a useful measure of toxicity.

The weaknesses of LD50 are adequately described in other sections. Where it was placed, this implied that the animal cruelty concerns outweighed the value of the measurement, which would be an unsourced judgement rather than a statement of fact. —Preceding unsigned comment added by 71.227.165.106 (talk) 08:20, 2 July 2010 (UTC)

LSD human LD50[edit]

How was this site not a good source for the human LD50 of LSD? --Whoop whoop pull up Bitching Betty | Averted crashes 00:09, 18 June 2011 (UTC)


seems to be a solid reference which correlates perfectly with the data the CIA produced in the 50s and 60s 121.99.56.29 (talk) 20:09, 20 July 2014 (UTC)

Why...[edit]

...is Ionizing radiation in the list? Since it can't be directly compared, via mg/g, it is only confusing and offers no understanding to the article topic. I would simply remove now, but perhaps there is a good reason that I just haven't deduced, and wanted to hear it before I simply deleted that entry. Dennis Brown (talk) 15:10, 3 August 2011 (UTC)

True it can't be directly compared to the other entries, but you can have a median lethal dose of radiation. Another entry on the list, ADBAC, lists mg/L (concentration in the aquatic environment instead of in the body), which also can't be directly compared to other entries on the list (it also has a mg/kg value). I can see the rationale (though not a real need) for removing it from the table, but it probably should stay in the article.--Wikimedes (talk) 06:47, 1 August 2012 (UTC)
Well, it took less than a year, so the talk page is faster than ArbCom ;) I will defer to your superior experience here. I had forgotten about this question entirely. Thanks for answering and pinging me. Dennis Brown - © Join WER 10:55, 1 August 2012 (UTC)
My 2 cents is that it should agree with the page on Gray (unit) which says: "A whole-body acute exposure to 5 gray or more of high-energy radiation usually leads to death within 14 days." However, since nothing is cited in either place, perhaps more info is needed. thx 8 August 2016

sorting table by LD50[edit]

I started formatting the table so that it could be sorted by LD50 before I saw that it was listed in decreasing order of LD50. This should be unnoticeable for the reader, except that now about 1/3 of the values in the LD50 column will sort correctly whereas previously ~0 would. I'll leave it where it is rather than continuing to make an unnecessary change or undoing work that might be useful later.--Wikimedes (talk) 06:31, 1 August 2012 (UTC)

what happened to all those http://msds.chem.ox.ac.uk sources?[edit]

Seemed these sources are no longer working. It has stated: "The University of Oxford Department of Chemistry MSDS web resource is no longer being maintained. Since this resource provided safety information it is not appropriate that the MSDS web resource is still used as a reference resource. The manufacturers and suppliers have a legal duty to provide and maintain MSDS information for the chemicals that they sell. Please refer to the suppliers web pages for safety information and data sheets."--Inspector (talk) 13:21, 8 February 2013 (UTC)

Unfortunately it seems that their robots.txt didn't let archive.org archive them either. Anyone know of any other sources or mirrors of them? SubTenebra (talk) 20:14, 23 November 2014 (UTC)

source 32 directs to a webpage that does not load[edit]

source 32 directs to a webpage that does not load — Preceding unsigned comment added by 97.65.96.146 (talk) 21:29, 13 February 2013 (UTC)

Time to semi-protect this page for a while?[edit]

IPs seem to be repeatedly incorporating a link to a cartoon. Suggest semi-protect this page to prevent this. Lesion (talk) 14:35, 11 September 2013 (UTC)


Links Dead[edit]

All the references to MSDS are dead now, and it seems like they have been since 2011. Either remove the references or try provide another resource. (at this point this concerns reference numbers 7, 12, 14, 15, 16, 21, 22, 35, 36,37 and 40 (that's a lot)) — Preceding unsigned comment added by 217.189.227.94 (talk) 03:11, 18 February 2014 (UTC)

Typical probability distribution[edit]

Is there a typical probability distribution that can be derived from just the LD50 value and that works for most toxins? If so, this should be stated in the article. If not, of what value is LD50 alone? --Mudd1 (talk) 18:47, 23 February 2014 (UTC)

Revert of redirect to lethal dose[edit]

I note this article was deleted and redirected to median lethal dose, removing some content. Acknowledging the need for bold edits, by user:Emily Temple-Wood (NIOSH) who is a wikipedian in residence, deleting such significant amounts of content, and merging content needs at least some discussion on talk pages. 2001:44B8:21B:8F00:D1A0:8003:7AF8:7DA (talk) 12:49, 10 July 2015 (UTC)

Hi anon, sorry it took me so long to get back to you - I've just gotten back from vacation and I had a bit of a backlog to catch up on. There was a discussion involving User:DePiep and others who I can't recall right now on Template talk:Chembox about merging the content. If I left something out while merging that wasn't duplicated elsewhere, please feel free to add it back. :) Best, Emily Temple-Wood (NIOSH) (talk) 20:51, 12 July 2015 (UTC)
re IP: No you cannot claim back-in-time discussion in this. When you say 'significant amounts of content' were deleted without you linking to them, that's not enough (but this illustrated that you do know what I am talking about). You do do can open a fresh talk on it. Good quotes or diffs wold make your case stronger. (To be clear: you post here did not give me a clue about your issue). -DePiep (talk) 21:39, 12 July 2015 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just added archive links to one external link on Median lethal dose. Please take a moment to review my edit. If necessary, add {{cbignore}} after the link to keep me from modifying it. Alternatively, you can add {{nobots|deny=InternetArchiveBot}} to keep me off the page altogether. I made the following changes:

When you have finished reviewing my changes, please set the checked parameter below to true to let others know.

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers. —cyberbot IITalk to my owner:Online 03:36, 27 August 2015 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified one external link on Median lethal dose. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at {{Sourcecheck}}).

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers.—cyberbot IITalk to my owner:Online 15:48, 1 April 2016 (UTC)

LD50 table does not sort correctly[edit]

I noticed that when sorting by LD50 it does not sort in numerical order, but instead considers each value as a character string and sorts them alphabetically. For example, 2 mg/kg is sorted as lower than 300 mg/kg. — Preceding unsigned comment added by YuliEuphemism (talkcontribs) 18:52, 2 September 2016 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified 3 external links on Median lethal dose. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers.—InternetArchiveBot (Report bug) 14:25, 21 May 2017 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Median lethal dose. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers.—InternetArchiveBot (Report bug) 11:28, 7 June 2017 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Median lethal dose. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

-- Source[17](http://msds.chem.ox.ac.uk/index2.html) is outdated. Please look for another source(and proceed to fix it) — Preceding unsigned comment added by 180.190.174.11 (talk) 16:37, 10 February 2018 (UTC)

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

You may set the |checked=, on this template, to true or failed to let other editors know you reviewed the change. If you find any errors, please use the tools below to fix them or call an editor by setting |needhelp= to your help request.

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

If you are unable to use these tools, you may set |needhelp=<your help request> on this template to request help from an experienced user. Please include details about your problem, to help other editors.

Cheers.—InternetArchiveBot (Report bug) 12:47, 26 July 2017 (UTC)