The QM2 scored an 84 in an inspection conducted June 10, with officials finding extremely dirty water in a splash pool, a hair in an ice making machine and chemicals stored near napkins, paper cups and utensils, CNN reported Saturday.
The government has two score classifications. A score under 86 is "not satisfactory," while a score of 86 or higher is "satisfactory."
Conditions found on the QM2 are unacceptable, said Carolyn Spencer Brown, editor in chief of CruiseCritic.com. She said failing scores for large ships are very rare -- there have been no failing grades since Albatross, a private ship, scored 69 in February 2010.
"I've been chronicling the CDC scores for 14 years and this one is unusually bad," Brown said. "What really bothered me was the use of the word 'filthy' five times."
The cruise ship is operated by Cunard Line. It said the ocean liner's recent "uncharacteristically low score" is a quirk and it has taken steps to prevent it from happening again.
"The poor assessment on 10 June resulted largely from one small area of the ship's overall operation. All the issues raised in the report were immediately addressed and have now been corrected," said Cunard spokeswoman Jackie Chase in a statement.