How is the 5-day incubation period defined?
The book, Laboratory Testing for BOD and CBOD, by Brake and Raynovic, is the only reference (until recently) that discusses an absolute definition (± 2 hours). Both EPA and older editions of Standard Methods are silent on the issue. The 21st Ed. of Standard Methods says + 6 hours. We believe that you should strive to stay as close to the actual 5 day incubation period as you can, but certainly stay within 5 days ± 4-6 hours.
