Novaform ComfortGrande and DreamAway mattresses sold exclusively at Costco are being recalled, with the U.S. Consumer Product Safety Commission saying they may have been exposed to mold during manufacturing.

The CPSC said that around 48,000 mattresses are being recalled by their manufacturer, FXI. The recall covers Novaform ComfortGrande 14-inch and Novaform DreamAway 8-inch mattresses, which are sold in twin, full, queen, king and California king sizes. The 8-inch mattress is sold in twin and full sizes.

The mattresses were made at FXI’s San Bernardino, California, facility between Jan. 2 and April 28.

The agency said the mattresses could have been exposed to water during the manufacturing process, allowing mold to develop. That would be a health risk to people with compromised immune systems, damaged lungs or an allergy to mold.

The CPSC said information about the manufacturing date and location can be found on a tag attached to the mattress.

It also said the ComfortGrande mattress has a blue base with ‘Novaform’ printed in white letters, and the DreamAway mattress has a gray base with ‘Novaform’ printed in white letters.

Customers who own the affected mattresses can contact FXI to receive either a full refund or a replacement. People who choose a replacement mattress will receive free shipping and free disposal of the recalled unit, the company said.

FXI can be reached toll-free at 888-886-2057, or on its website at novaformcomfort.com/pages/recall.