What happens at the end-of-life for the LifeStraw Sip? Is it recyclable, refillable, etc.? Is the filter replaceable?

The filter itself is not replaceable.  All pieces other than the membrane are recyclable.  To recycle, remove the silicone pieces and recycle.  Then, to extract the membrane from the straw, drill a hole into the bottom to loosen and remove the membrane - noting that this will damage the filter and render it unsafe so this should only be done when ready to discard the product.  Recycle the stainless steel and discard the inner membrane. 

Note: the product has a projected lifespan of 1,000 liters, but this is a conservative estimate based on longevity testing with dirty water and maintenance of flow rate.