DOH/DEP asbestos fact sheet draft, 105 Duane Street

NYC 9/11 Public Portal Document 12/11/2001 17:06 FAX 212 363 8306 ATC l 007

0 D 5755 contamination before taking cassettes into a clean prepara- tion area. hPPRO)uMATE

10.2 Perform sample preparation in a clean facility that has a separate work area from both the bulk and air sample t5

OEGREE

ANGLE

1- TO 1-i/2 preparation areas. OR 10.3 Initial specimen preparation shall take place in a 25 M44 TO 37MM clean HEPA filtered negative pressure hood to avoid any possible contamination of the laboratory or personnel, or

.1 "FIG. 1 Example of the Tubing Nozzle NC DIAMETER both, by the potentially large number of asbestos structures in an asbestos-containing dust sample. Cleanliness of the preparation area hoods is measured by the cumulative process blank concentrations (see Section 11). 10.4 All sample preparation steps 10.4.1 through 10.4.6 shall take place in the dust preparation area inside a HEPA hood. 10.4.1 Remove the upper plug from the sample cassette sample area of 100 cm 2 is vacuumed until there is no visible and carefully introduce approximately 10 mL solution of a dust or particulates matter remaining. Perform a minimum 50/50 mixture of particle-free water and reagent alcohol into of two orthogonal passes on the surface within a minimum the cassette using a plastic wash bottle (7.44). If the plugged of 2 min of sampling time. Avoid scraping or abrading the surface being sampled. (Do not sample any debris or dust nozzle was left attached to the cassette, then remove the plug particles greater than I mm in diameter (see 4.2).) Smaller or and introduce the water/alcohol solution into the cassette larger areas can be sampled, if needed. For example, some through the tubing, and then remove the tubing, if It is surfaces of interest may have a smaller area than 100 cm2. visibly clean. Less dusty surfaces may require vacuuming of larger areas. 10.4.2 Replace the upper plug or the sample cap and Unlike air samples, the overloading of the cassettes with dust lightly shake the dust suspension by hand for 35. will not be a problem. As defined in 3.2.5. only dust shall be 10.4.3 Remove the entire cap of the cassette and pour the suspension through a 1.0 by 1.0 mm opening screen (7.46) collected for this analysis. 8.8 At the end of sample collection, invert the cassette so into a pre-cleaned 200 mL glass specimen bottle (7.9). All that the nozzle inlet faces up before shutting off the power to visible traces of the sample contained in the cassette shall bi the pump. The nozzle is then sealed with a cassette end-plug rinsed through the screen into the specimen bottle with a ad the cassette/nozzle taped or appropriately packaged to plastic wash bottle containing the 50/50 solution of particle- prevent separation of the nozzle cassette assembly. A free water and alcohol. Repeat this procedure two additional times for a total of three washings. Next, rinse the nozzle two and

second option is the removal of the nozzle from the cassette, then plugging of the cassette and shipment of the nozzle (also or three times through the screen into the specimen bottle plugged at both ends) sealed in a separate closeable plastic with the 50/50 mixture of water and alcohol. Typically, the beg. A third option is placing the nozzle inside the cassette total amount of the 50150 mixture used in the rinse is 50 to for shipment. The nozzle is always saved and rinsed because 75 mL. Discard the 1.0 by L.0 mm screen and bring the a significant percentage of the dust drawn from a lightly volume of solution in the specimen bottle up to the 100 ml. Loaded surface may adhere to the Inside walls of the tubing. mark on the side of the bottle with particle-free water only. 8.9 Cheek that all samples are dearly labeled, that all dust 10.4.4 Adjust the pH of the suspension to 3 to 4 using a sampling information sheets am completed, and that all 10.0 % solution of acetic acid. Use pH paper for testing. pertinent information has been enclosed. in accordance with Filter the suspension within 24 h to avoid problems associ- laboratory quality control practices, before translhr of the ated with bacterial and fungal growth. samples to the laboratory. Include an unused cassette and 10.4.5 Use either a disposable plastic filtration unit or a nozzle as a field blank glass filtering unit (7.14) for filtration of aliquots of the 8.10 Wipe off the exterior surface of the atssettea with suspension. The ability of an individual filtration unit to disposable wet towels (baby wipes) prior to packaging for produce a uniform distribution may be tested by the shipment filtration of a colored particulate suspension such as diluted India Ink (suspension of carbon black). 9.. Sample Shipment 10.45.1 If a disposable plastic filtration, unit is used, then 9.1 Ship dust samples to an analytical laboratory in a unwrap a new disposable plastic filter funnel unit (either 25 or 47 mm diameter) and remove the tape around the bast of sealed container, but separate from any bulk or air samples. the funnel. Remove the funnel and discard the top filter The cassettes must be tightly sealed and packed in a material supplied with the apparatus, retaining the coatye free of fibers or dust to minimize the potential for contami- polypropylene support pad In place. Assemble the unit with nation. Plastic "bubble pack- is probably the most appro. print material for this purpose. the adapter and a properly sized neoprene stopper, and attach the funnel to the 1000 mL side arm vacuums , Bask (7.15). Place a 5.0 µm pore size MCE (backing filter) on the 10. Sample Preparation support pad. Wet it with a few mL of particle-free water and 10.1 Under a negative flow HERA hood (7.5), carefully place an MCE (7.16) or PC filter (x0.22 µm pore size) (7.17) wet-wive the exterior of the cassettes to remove any possible on top of the backing filter. Apply a vacuum (7.36), ensuring

NYC-WTC 000125907