Recommended THC home tests

1
Hello
I am wondering if anyone can recommend a THC home test kit ? The company I work for is rolling out a random drug test policy and all the tests I can find do not test to a low enough Nano gram. The levels they are willing to allow are 15ng/ml for a urine test and 2 ng/ml for oral swab. So far all I have been able to find are positive/negative result swab tests and 25 ng/ml urine tests. Thanks
cron