Do you know what lab your company uses? For example, Quest Diagnostics' MJ test has a concentration cut off level of 50 ng/mL https://www.questdiagnostics.com/home/companies/employer/drug-screening/products-services/urine-test/urine-process-certifications.html which is pretty standard because most labs follow that which is SAMHSA's Mandatory Guidelines for Federal Workplace Drug Testing Programs. If the test strips you ordered have the same cut off standard and good reviews, you should be able to rely on them. I have found these to be reliable. https://www.amazon.com/Instant-Single-Panel-Drug-Test/dp/B004C39D68