Standard Test Method for Determination of 2,4-Toluene Diisocyanate (2,4-TDI) and 2,6-Toluene Diisocyanate (2,6-TDI) in Air (with 9-(N-Methylaminomethyl) Anthracene Method) (MAMA) in the Workplace

Importancia y uso:

5.1 TDI is used mostly in the preparation of rigid and semi-rigid foams and adhesives.

5.2 Diisocyanates and polyisocyanates are irritants to skin, eyes, and mucous membranes. They are recognized to cause respiratory allergic sensitization, asthmatic bronchitis, and acute respiratory intoxication (6-9).

5.3 The American Conference of Governmental Industrial Hygienists (ACGIH) has adopted a Threshold Limit Value–Time Weighted Average (TLV-TWA) of 0.001 ppm of 0.007 mg/m³ with a Short-Term Exposure Limit (STEL) of 0.005 ppm or 0.036 mg/m³ for either 2,4–TDI, or 2,6–TDI, or for a mixture of 2,4– and 2,6–TDI (10). The Occupational Safety and Health Administration of the U.S. Department of Labor (OSHA) has a permissible exposure limit of 0.02 ppm(V) or 0.14 mg/m³ of 2,4-TDI as a ceiling limit and 0.005 ppm (V) or 0.036 mg/m³ as a time-weighted average (11).

5.4 Monitoring of respiratory and other problems related to diisocyanates and polyisocyanates is aided through the utilization of this test method, due to its sensitivity and low volume requirements (15 L). Its short sampling times are compatible with the duration of many industrial processes and its low quantification limit also suits the concentrations often found in the working area.

5.5 The segregating sampling device pertaining to this proposed test method physically separates gas and aerosol allowing isocyanate concentrations in both physical states to be obtained, thus helping in the selection of ventilation systems and personal protection.

5.6 This test method is used to measure gaseous concentrations of 2,4- and 2,6-TDI in air for workplace and ambient atmospheres.

Subcomité:

D22.04

Volúmen:

11.07

Número ICS:

13.040.30 (Workplace atmospheres), 71.040.40 (Chemical analysis)

Palabras clave:

air monitoring; dual filter sampling system; high-performance liquid chromatography; sampling and analysis; toluene diisocyanate; workplace atmospheres; 9-(N-methylaminomethyl) anthracene;