What happened

Shares of Stericycle (SRCL -0.47%) stock are down 15.1% as of 10:15 a.m. EDT this morning after the hazmat waste disposal company reported disappointing first-quarter earnings last night.

Wall Street estimates had called for earnings of $0.82 per share, but Stericycle reported just $0.57 pro forma. The company likewise missed sales estimates, reporting just $830.1 million, whereas $864.1 million had been expected.

Glowing red stock arrow trending down

Image source: Getty Images.

So what

And that's the good news. The bad news is that when calculated according to generally accepted accounting principles, Stericycle didn't earn any profit at all. To the contrary, GAAP results for the quarter showed a $0.42-per-share loss, versus Stericycle's $0.25-per-share profit in last year's Q1.

Sales were down 7% year over year, a fact management blamed on "year-over-year foreign exchange impact and expected softness in recall activity," and also apparently "significant weather impacts."

Now what

Investors don't seem to be buying those explanations, however, and perhaps they shouldn't. After all, Stericycle also announced today it is replacing its current CFO, Daniel Ginnetti, with Janet Zelenka, who most recently served as CFO of Staples subsidiary Essendant for 15 years.

The addition of new blood to the company may help Stericycle reverse a long-term trend of five straight years of declining earnings. For the time being, however, investors are withholding their endorsement -- and given the size of today's loss, I can't say that I blame them.