The phrase "age limit" refers to the specific age at which something is allowed or restricted, indicating the highest or lowest age one must be to participate in or access something. Full definition
Few had concrete suggestions, but a few spoke in favor of raising age limits for buying assault weapons. (sun-sentinel.com)
If the technique does hold up under further investigation, it could raise ethical questions over the upper age limits of pregnancy — and whether there should be any. (newscientist.com)
There is no upper age limit on spaying; however, an animal must be healthy enough to successfully make it through the surgery. (caninejournal.com)