The problem? It called it "phosphorous."
Phosphorus is a chemical element. It is a noun.
Phosphorous is an adjective meaning "pertaining to or of phosphorus."
(This is not a nitpick at all. This is a pretty significant and central part of grammar. And spelling, too, I suppose.)
In this era of being able to instantly produce links to websites such as the above, or even more reputable sites than open source ones like the wiki derivative projects, there is no excuse for even the tiniest and poorest-staffed newspaper to make a mistake like that. If one isn't sure of the exact spelling of a word (or if it's a word one is less than perfectly familiar with) one should double-check with a quick Google search. If the author doesn't catch it, the editor ought to double-check.
If the editor doesn't catch it, people are going to berate you for it on the internet.
I don't get after people who make this kind of mistake on their personal websites. After all, such people aren't generally charging for content and they don't have any kind of editors or oversight. It's forgivable when a one-person operation goofs like that, especially on a project that they might devote less than an hour of their time a day to. But this mistake made it past multiple educations that ought to have been at least high school diploma level, and anyone with a high school education could have (I'm not saying would have, I'm saying "could have if they did their work and retained it"-I'm well aware not everyone with that level of education definitely absorbed that much) caught such an error.
Further, institutions like newspapers (and other print publishers) do play an important role in a modern society. Along with other media, print media forms the central part of one of the great pillars of modern society: Communications. (I'd go so far as to call it one of the big two or three pillars, for that matter.)
Sure, people will know what "phosphorous" was supposed to mean. Most people won't even notice it was an error. But even a small error should be acknowledged and have attention brought to it in this case. Ignored errors lead to ignorance. Ignorance leads to apathy.
Apathy leads to
Stupidity leads to suffering. (And I do mean that one.)
When communications break down, society will start to crumble. Please, stop the rot at the low levels (i.e. puny and rather lame local newspapers) rather than let it creep up.
(Obviously, education is important for this. Yeah, the other two of the big three pillars of modern society? Education and technology.)