The demand for packaging of cannabis products has increased over the past five years.  There are a lot of packaging companies in the space competing for this business.  This includes overseas packaging companies.  Time will tell where this market lands, but you can expect the demand to increase and new innovative and sustainable materials/desgins will lead the way.

The Consumer Product Safety Commission is responsible for the requirements for child safety in packaging in the US.  This relates to all products from household chemicals to pharmaceuticals and is specifically defined in the Poison Prevention Packaging Act (PPPA) of 1970.  The EPA regulates pesticides and other chemicals that require child resistant packaging.  The actual test requirement is specifically defined for child safety (testing children) and senior friendly (testing seniors).  The full test can be found by looking up 16. CFR 1700.20 in the Federal Register.

You will not find marijuana listed in the federal regulation for products requiring child resistant packaging.  The reason is that marijuana is still federally illegal and the CPSC does not have any involvement.  Since the CPSC standard is the only standard used in the US for testing and certifying a package to be child resistant.  Most cannabis state regulators defer to this standard in their specific state regulations.  

The answer to your question is not simple.  There are different types of child resistant packages for single dose/use products vs. multi dose products.  The cannabis packaging industry is coming up with new solutions all the time.  We have the basic stock bottles and bags/pouches, but there are also new reclosable boxes that are paperboard as well as plastic, blister packages and more.  You can customize stock packages as well as develop your own custom package for your specific product.   Part of your packaging choice should be based around your production process and what package best fits your operation and assembly goals.  
These are the technical issues, but there are also branding needs that will drive the package you choose to distinguish your product in the market.  Find the right packaging supplier to help you meet your goals.

Child resistant packaging has been defined as meeting the Consumer Product Safety Commission test protocol.  Design of these packages starts wtih understanding the materials, function, costs and user acceptance.  The nature of the test is subjective, because actual children and adults are used for this testing. My suggestion is to start out by working with an ASTM certified testing lab with a lot of experience testing child resistant packaging according to CPSC guidelines.  These professionals can give you good advice and guidance on your package before testing.  Usually, the best approach is to build multiple steps into the opening feature that a child of the test age does not have the cognitive skills to figure out quickly.  The other design feature is to consider the size and strength of the childs hand vs the adult hand and use that information to direct your design.  Protect your investment with a patent attorney to make sure you are not using an opening feature that is already patented by someone else. Testing is expensive, so you want to make sure your design will pass the first time.  This is not always possible, and you might have to modify and retest for the best possible outcome.