ASTM - P230
Proposed Test Method for Measurement of Occupational Exposure to Formaldehyde (Passive Sampler Methodology)
|Publication Date:||1 January 1991|
1.1 This proposed test method describes personal or area measurements of occupational exposures to formaldehyde. Formaldehyde is collected in a passive diffision sampler, and analyzed by a calorimetric method using 3-methyl-2-benzothia
1.2 The sampling method gives a time-weighted average (TWA) sample and can be used to determine compliance with the 15 min short-term exposure limit (STEL).
1.3 The applicable concentration range for an 8 h TWA sample is 0.15 to 3 mg/m3 (0.12 to 2.5 ppm v/v). This range is based on using an aliquot of 5 mL of absorbing solution in the prescribed sampler equipped with a slow sampling rate cap for a period of 8 h and observing a minimum difference of 0.05 absorbance units from the blank when using spectrophotometer cells of path length 1 cm.
1.4 The applicable concentration range for a 15 min STEL sample is 1.0 to 20 mg/m3 (0.8 to 15 ppm v/v). This range is based on using an aliquot of 5 mL of absorbing solution in the prescribed sampler equipped with a fast sampling rate cap for a period of 15 min and observing a minimum difference of 0.05 absorbance units from the blank when using spectrophotometer cells of path length 1 cm.
1.5 Water soluble aliphatic aldehydes give a significant positive interference (1, 2), nearly equal to formaldehyde on a molar basis. Further information on estimating potential and actual interferences from aliphatic aldehydes may be found in 6.2 and 12.1.7, respectively. Most other compounds which react to produce colored products are not gaseous or water soluble and, consequently, should not interfere.
1.6 This proposal does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this proposal to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.