Heathrow staff are set to walk out for four days from February 2 and again from February 22.
The Unite union has warned that during this strike, mislaid baggage could disappear forever.
That figure translates to just under six bags per 1,000 passengers.
In addition, SITA found that lost luggage cost airlines around the world $ 2.1 billion in 2016.
Last year, Birmingham Airport was found to be the airport that passengers were most likely to lose their luggage and never see it again.
The Civil Aviation Authority (CAA) date on lost luggage revealed the top 10 airports for unsolved lost luggage by total number of claims.