Hyphens, En Dashes, Em Dashes

Q. Which is correct: “minimum food-safety standards” or “minimum food safety standards”? Thank you.

A. According to the hyphenation table at CMOS 7.89, a phrase like “food safety”—in which one noun (“food”) modifies another (“safety”)—would be hyphenated as a modifier before another noun. In other words, you’d write “food-safety standards” (with a hyphen). Adding “minimum” doesn’t change that: “minimum food-safety standards.”

That’s Chicago style, strictly interpreted, and you could stop there.

But a look at Google Ngram Viewer suggests that the phrase “food safety standards” has rarely appeared with a hyphen in published prose, maybe because standards for food safety and safety standards for food are pretty much the same thing, so a hyphen isn’t needed for clarity. A hyphen in the larger phrase—“minimum food-safety standards”—is a little more helpful (preventing a momentary misreading in which safety standards apply to “minimum food,” whatever that might be), but not much.

You’ve landed on one of those gray areas that tend to (or tends to?) drive writers and editors up the wall. A hyphen may help some readers—and it’s rarely considered wrong to add one in this scenario (see CMOS 7.85)—but it doesn’t seem to be customary in this particular phrase. If you’re looking to justify leaving it out, cite common usage and CMOS 7.84: “Where no ambiguity could result . . . hyphenation is unnecessary.”