Spray Application with Isocyanates

HISTORICAL REVIEW OF THE WATER TANKS

4

July 9, 1964• Water

Tanks• 9’ tall• 40’ long• Direct

bury

5

Tanks (left)

50 YEARS LATER

7

Tank Room

WHAT IS SPRAY MATERIAL?Part A + Part B

9

MDI FormsPart A is 4,4’ MDI (100%)

ISSUES AND RESOLUTIONS

What is this material found around tanks?

MDI SAMPLING PROTOCOLS

13

4,4'-diphenylmethane diisocyanate (MDI) MDI Sampling Methods

• MDI has a very low vapor pressure (good) and very reactive (good/bad). So, the vapor is not likely present outside the tank being sprayed, having reacted very quickly. Aerosols do exist and cause the same symptoms as vapor.

• MDI aerosol has many test methods. The one we chose was OR-OSHA Method 1010 calling for midget impingers, toluene-DMSO based solution and MAMA impregnated post-filter.

• Impingers are not conducive to tank entry (will spill contents on entrant), and have a high probability of being coated.

• Passive dosimeters and direct-reading instrument capture vapor, not aerosol. • We looked for 4,4’ MDI monomer, not oligomer.

14

15

Monitoring for MDI Vapor

(colorimetric)

WHAT CONTROLS ARE USED?

16

REDUCE FOOT TRAFFIC TO THE BASEMENTAccess Control

17

SAMPLING METHODS

18

Sampling Methods

1. Impinger2. Glass Fiber Filter, open

face3. Direct Reading Instrument4. Passive Dosimeters

RESULTS

20

EXPOSURE RESULTS

21

QUESTIONS? The work we do is vital

22