This is one of the strictly required items. You will need a car seat or booster for your growing child from their birth until they are at least eight years old, by law in most states. Many parents like to start with a removable infant seat that can lock into a base that stays in the car, for ease of transporting their child. These infant car seats can also sometimes lock into stroller; together they're called a "travel system." If you don't mind fastening your baby into their seat in the car (instead of in a building), you could choose to start with a seat that will grow with your baby. To protect babies from neck injuries, the American Academy of Pediatrics recommends keeping children in a rear-facing seat until they are at least 2 years old.
Because car seats must meet the same stringent fire safety requirements as car interiors do, flame retardant chemicals have been used more in this product category than other baby products. Some manufacturers have succeeded in choosing materials that do not require flame retardants in most components; only one manufacturer offers a product entirely free of such chemicals. In addition, manufacturers reported solvents ethylene glycol, toluene, and ethyl benzene, and metals arsenic and antimony in car seats.
Finding the right car seat depends on many factors, and high price doesn't necessarily mean safest in a crash or easiest to use properly. Make sure the car seat comes with instructions for installation and use, and make sure you've properly installed it before bringing your new baby home from the hospital. If you are going to use a second-hand car seat, there are several things to check: the expiration date - the plastics used in car seats can become more prone to breakage after a certain age and cease to be safe in a crash; the manufacturers label with the date of manufacturer and model number - necessary so you can find out if the product is recalled; and if the car seat has ever been in a crash - the National Highway Traffic Safety Administration says any accident that is more than minor can compromise the structure, but some manufacturers recommend a new seat even after a minor accident. Never use a car seat that has been recalled.
The Ecology Center has identified two products - the Mesa Henry and Jordan car seats from UppaBaby - that is free of chemical flame retardants, though we don't have full information on other materials (the same is true of other car seats that still contain flame retardant chemicals). Some other brands have reduced flame retardant use through product redesign - for example, by designing seats that rely on flame retardants in fewer parts to meet flammability standards.
References & Resources
Ecology Center's Children's Car Seat Study 2016
Learn more about the hidden hazards by reviewing the glossary or take a deep dive by reading Safer Products for Babies and Toddlers: Resources and Recommendations for Retailers.