This is a yes and no question as I will explain.
There are different levels of EPA certification, to work with refrigerant the EPA 608 exam will be need to be taken and passed. The EPA 608 exam is broke down into four levels the core, type I, type II, type III and universal.
Each level type test passed allows someone to work on certain refrigeration systems.
Type I Certification —Can only work on Small Appliance (5lbs or less of refrigerant)
Type II Certification — Can only work on Medium, High and Very-High Pressure Appliances.
Type III Certification —Can only work on Low-Pressure Appliances.
Universal Certification — Has passed all the exam I, II ,III, core and can work on any system.
The type I exam can be taken online, but someone who has this can only work on a units with 5 pounds of refrigerant or less. This means refrigerators, small wall mounted coolers or any small refrigeration unit that has no more than 5 pounds of refrigerant.
Residential and commercial will be off limits and will not be able to be worked on unless the type II and III, EPA 608 test exams are taken and passed.
To take and pass the type II and III exams they must be proctored. Meaning you have to go to a physical location have your ID checked and be watched while the test is taken. There is no certification for taken type II and III online.
Only having the type I exam is kind of useless since it limits most of the units that are worked on today, which are residential and commercial. Old refrigerators and old wall mounted refrigeration units are rarely worked on and a new one is simply bought and installed. Wall mounted units cost between a hundred and three hundred dollars and new unit are much more efficient then a five or ten year old model. Refrigerators are almost the same.
This will be different for everyone and I am sure that there are people that only need a type I EPA certification. If this is the case then yes it can be taken online. Be sure to take it at a real online site and not just some scam site. Mainstream engineering is a trusted source for all the certifications so if you do decide to go for only type I EPA 608 exam then this would be a good place to go.
Step by Step passing the EPA 608 certification exam, including the Core, Type I, Type II, and Type III test with practice questions