MOTD points out a less-than accurate description of the preservative TBHQ in Michael Pollan's The Omnivore's Dilemma (as posted at Jims Empire).
While MOTD deftly points out (contrary Pollan)that a butane group does not lighter fluid make, his calculations on the TBHQ content of the typical nugget miss the mark. Unfortunately, as commenter rehana points out, MOTD's estimate of 312.5 nuggets to reach the 1 gram level at which TBHQ causes "nausea, vomiting, ringing in the ears, delirium, a sense of suffocation, and collapse." (as Pollan quotes from A Consumer's Dictionary of Food Additives), is based on 0.02% of the total nugget weight, while the FDA regulation applies to the oil in the nugget, and thus somewhat low.
Fortunately, McDonald's provides us with the total fat content of an order of nuggets (49 g in a 20 piece), which serves us well as a more precise upper bound for the oil content of a nugget. If all the fat in the nugget were to be oil (obviously not true, since there actually is some chicken in there), the FDA maximum content of TBHQ per nugget would be 0.0049 g per nugget, necessitating the consumption of 2040.82 nuggets to reach the threshold Pollan describes.
Of course, at 15.3% fat by weight, there are reasons other than preservatives that make it wise to consume these chunks of over-processed tastiness in moderation.