3M ™ Formaldehyde Diffusion Monitor 3720/3721 – Preparation and Use Good industrial hygiene practice indicates that a blank monitor be included with each set of samples to check for any contamination of the samples. The blank should be opened when the sample is opened. To open the can: a) Remove the plastic lid from the top can. b) Open both cans by grasping the ring tabs and pulling up. After opening the can, examine the contents carefully to make sure all of the parts listed below are included: a. TOP CAN: i. Pour spout (plastic straw) ii. Elution cap (clear plastic with plugs) iii. Top section (purple with white membrane on top) iv. Bottom cup (Clear plastic with white label). b. BOTTOM CAN: i. Bottom section (purple with metal clip) ii. Moisture retaining cap (clear plastic). To prepare the blank monitor: a) Remove the cap off the back section. b) Remove the top section from the bag. c) Ensure the bottom cap is removed from the top section. d) Snap the top section to the bottom section. e) Remove the plastic ring and white film from the top section. f) Immediately snap the elution cap (with plugs) onto the top section of the monitor. g) Snap the two port plugs closed. h) Separate the top and bottom section of the monitor and discard the bottom section. i) Snap the bottom cup into the bottom of the top section and ensure the cup is securely snapped in place. j) Write the word “Blank” on the back of the monitor. k) Return the blank monitor into the can and close the can with the plastic lid provided. To prepare the sample monitor for use: a) Record the following information on the form enclosed with the monitor: a. Monitor serial number b. Sampling date c. Employee ID or area d. Temperature and relative humidity e. Start time b) Remove the moisture retaining cap from the bottom section of the monitor and discard. c) IMMEDIATELY after removing the moisture retaining cap, snap the top and bottom sections together. d) DO NOT remove the white film and plastic ring. The diffusion monitor may be used as a personal monitor or area monitor. As a personal monitor, it should be worn near the worker’s breathing zone. For example, it is often attached to the front of the shirt collar. When used as an area monitor, hang it away from walls, corners, table tops or other regions where air movement in the room may be limited. © 3M Company December, 2007. All rights reserved.