Phthalates free is something that doesn't contain or something that exists without the presence of phthalates.
Phthalates are a group of chemicals used to make plastics more flexible and harder to break. They are often called plasticizers. Some phthalates are used as solvents (dissolving agents) for other materials. They are used in hundreds of products, such as vinyl flooring, adhesives, detergents, lubricating oils, automotive plastics, plastic clothes (raincoats), and personal-care products (soaps, shampoos, hair sprays, and nail polishes).
Phthalates are used widely in polyvinyl chloride plastics, which are used to make products such as plastic packaging film and sheets, garden hoses, inflatable toys, blood-storage containers, medical tubing, and some children's toys.
People are exposed to phthalates by eating and drinking foods that have been in contact with containers and products containing phthalates. To a lesser extent exposure can occur from breathing in air that contains phthalate vapors or dust contaminated with phthalate particles. Young children may have a greater risk of being exposed to phthalate particles in dust than adults because of their hand-to-mouth behaviors. Once phthalates enter a person's body, they are converted into breakdown products (metabolites) that pass out quickly in urine.
Know more about phthalates at CDC.gov.
Find out How to Avoid Phthalates in Plastics and Cosmetics from Men's Journal.