Tethers may be a requirement in California, where everything from cotton ***** to cotton candy have been known to cause cancer. However, in non-nanny states they are not.

 

"Tethers may be a requirement in California, where everything from cotton ***** to cotton candy have been known to cause cancer. However, in non-nanny states they are not. "

Actually since the manufacturer states they are a requirement and most states have a proper use clause, yes they do have to be used everywhere. Not just California. This is your kid we are talking about, these seats are designed by engineers. Try looking on youtube at videos about how the seats react in accidents and you will clearly see why they are there and why they are required!