EPA Method 316
Formaldehyde (Mineral Wool & Wool Fiberglass)
Method Overview
- • Isokinetic sampling.
- • Sampling train and operating procedures are similar to
M5 except that M316 requires reagent grade water in impingers.
- • 30 cubic ft minimum sample volume.
- • NOTE - High sulfite concentrations in the stack gas are
a negative interferent. (Special precautions are available to detect
and correct this problem.)
- • Formerly known as the "NAIMA Method."
- • Analysis is by the modified pararosaniline method, with
spectrophotometer set at 570 nm.
- • Validated for mineral wool fiberglass production facilities.
Target Compounds
Method Summary
- • The source is sampled isokinetically and formaldehyde absorbed
in DI water. Samples are shipped to the lab cold.
- • The impinger contents and DI train rinses are analyzed
by spectrophotometer. At Enthalpy, samples are derivatized with
pararosaniline and sodium sulfite to create a purple chromophore.
The chromophore is analyzed by spectrophotometer set at 570 nm.
- • Additional analytical details: Dilutions are made before
the derivatizing reagent is added. Samples must be allowed to warm
to room temperature just before reacting. Samples must react at
least 1 hour before analysis. A slope of the calibration curve that
is not within 10% of .5 reveals a problem with the standards or
the instrument. The slope holds to Beer's Law; if the pathlength
of each instrument is the same, the slope should likewise be the
same save for minor differences from electronic processing.
Quality Assurance
- • Field blank
- • Lab QA: we prepare new sodium sulfite reagent every day,
and each day prep and analyze new working standards.
- • Enthalpy uses reagent water to set zero on the spectrophotometer.
Shipping Tips
- • Hazardous shipping is not required unless formaldehyde
concentrations are extremely high.
- • Ship samples cold.
- • Please include a completed Chain of Custody (COC) form
with each cooler.
- • See Enthalpy's Download page for a printable COC form.
Enthalpy Experience
- • Enthalpy has nationwide environmental service contracts
with clients in the mineral wool industry, and we analyze Method
316 samples regularly and often.
- • Enthalpy uses a Hewlett Packard 8452 scanning diode array
spectrophotometer, (which is a bit of a step up from the Milton
Roy Spec 20 we ran in Chem Lab 101.)
- • We have devoted considerable time and resources to discussing
nuances and weaknesses of the method with the industry experts who
developed it, and we can advise in advance when a test situation
may prove inappropriate for the method.
