Final answer:
The mandatory EPA equipment certification went into effect on December 28, 2015, following the final rule signing on October 1, 2015, as part of the broader EPA regulatory framework.
Step-by-step explanation:
The EPA equipment certification requirement's mandatory certification went into effect on December 28, 2015. This came after the final rule was signed on October 1, 2015. The certification pertained to the standards set by the Environmental Protection Agency (EPA) to control the release of harmful emissions and ensure environmental safety.
The certification requirements are a part of the broader regulatory framework established by the EPA to manage various environmental issues, which include air and water quality, mercury emissions, and fuel efficiency in vehicles. These regulations have been subject to various revisions and adaptations over time, due to economic concerns, political directives, and the changing needs for environmental protection.