Frequent Questions

What is the "two significant figures" guideline?

Please explain the “two significant figures” reporting guideline.

For non-PBT chemicals, estimates are not required to be reported to a greater accuracy than two significant figures (e.g., 4224 may be entered as 4200).  The number of significant figures is the number of non-zero digits. One significant digit may be reported if the estimation techniques used do not support two digit accuracy. For PBT chemicals, if a facility’s release or other management calculations support reporting an amount that is more precise than two significant digits, then the facility should report that more precise amount (64 FR 58734, October 29, 1999).


Have more questions? Submit a request