What is the safest fabric for baby sleepwear?

The safest fabrics for baby sleepwear are GOTS-certified organic cotton and untreated merino wool. Organic cotton is soft, breathable, and hypoallergenic, grown without synthetic pesticides and processed without formaldehyde, chlorine bleach, or synthetic dyes. When sewn in snug-fitting designs, organic cotton sleepwear meets flammability standards without needing chemical flame retardant treatments.

Merino wool is another excellent choice for baby sleepwear because it naturally regulates temperature, wicking moisture away when the baby is warm and providing insulation when cool. Merino is also naturally flame-resistant and self-extinguishes, which eliminates the need for any chemical flame retardant additives. Its fine fibers are soft enough for sensitive baby skin.

Avoid sleepwear made from polyester, treated cotton blends, or fabrics marketed as stain-resistant, as these are more likely to contain PFAS, formaldehyde, or flame retardant chemicals. Always look for GOTS or OEKO-TEX Standard 100 Class I certification, which is the strictest level designed specifically for infant products. ONDU supports brands that meet these standards for peace of mind.