House Bill No. 6278 seeks to limit the use of animal testing by manufacturers and contract testing facilities when alternative methods are available. It defines "alternative test methods" as those that either provide equivalent or superior scientific quality without using animals or minimize animal use and suffering when non-animal methods are not feasible. The bill allows exceptions for medical research related to human and animal diseases, under specific conditions, and establishes definitions for key terms such as "animal," "animal test method," and "validation body." Importantly, the bill emphasizes that it does not prohibit the use of non-animal testing methods. The provisions regarding animal testing will take effect on October 1, 2025.

In addition to animal testing regulations, the bill mandates the gradual incorporation of biodiesel into diesel fuel sold in retail establishments and used by state-operated vehicles, vessels, and construction equipment. Starting July 1, 2025, all diesel fuel sold from April to November must contain at least 5% biodiesel, increasing to 10% by July 1, 2027, and 20% by July 1, 2029. For state fleet vehicles, the biodiesel requirement is set at 5% by July 1, 2025, and 20% by July 1, 2027. The bill defines "biodiesel" as fuel derived from vegetable oils or animal fats that meet specific standards, promoting a transition to more sustainable fuel sources. The biodiesel requirements are effective immediately upon passage.