Tetrahydrocannabinolic acid (THCA) is a non-psychoactive cannabinoid found in raw cannabis flower. In cannabis plants, THCA is an acidic precursor to the psychoactive tetrahydrocannabinol (THC) compound. As the cannabis plant ages or undergoes various decarboxylation methods, THCA slowly converts into THC.

The short answer is yes, THCa is legal in most states. In 2018, the United States revised the Farm Bill, creating a legal distinction between hemp and marijuana plants, which defined hemp as cannabis plants with less than 0.3% THC by dried weight.

THCa is generally considered to be safe, as it does not produce psychoactive effects (unless it is heated). There are a few considerations for safety, however, such as the quality of the product and the individual's genetics and lifestyle.

For example, tested samples of raw cannabis extracts have found traces of pesticides and irritating solvents that can cause harm and injury when taken in large quantities. This is why it's so important to shop for cannabis products from trusted sources that provide third-party lab testing for its safety.

Independent third-party testing takes place when an unrelated party analyzes a product through rigorous testing. Since the testing facilities have no obligation to the manufacturer selling the product, the process is unbiased. 

These tests show the product’s potency, quality, and purity. Third-party testing not only benefits consumers but also lets cannabis companies know if something is off in the manufacturing process.