Wipe sampling is a method for ascertaining potential contact exposure by determining the amount of a substance on commonly contacted surfaces. The main focus is usually on areas contacted with bare skin. In the work environment, this would typically be the skin of the hands. Of most concern are the areas where eating, drinking, smoking, or applying makeup occur. Break rooms, lunchrooms, and bathrooms should be the focus of any wipe sampling where a potential exists for the contaminant to be tracked or otherwise brought into these areas.
Although surfaces where skin makes frequent contact is typically the focus, wiping other surfaces can also be beneficial. Determining the amount of surface contamination around a process that generates the substance in question — even at varying distances from the source — can help determine the extent to which the substance has escaped the process.
Wipe samples can be taken on the same day the inspection is opened much more readily than full-shift personal air monitoring. Full-shift personal air sampling is virtually impossible to perform on the first day. If there are no levels of the contaminant found on the surfaces surrounding a process and those surfaces have not been cleaned recently, it may be determined that no air monitoring need be conducted.
The template square is used as a means to know the exact surface area being wiped. The template can be made of virtually any material, but paper is usually the material of choice as its disposable and cheap. KYOSH utilizes a square of card stock with a square center cutout measuring 10 cm-by-10 cm, giving a surface area of 100 cm².
Cheap and disposable come in handy since a new template must be used with each wipe sample taken.
- Use an OSHA-91(S) form to record wipe samples. There won’t be any equipment or calibration entries. No employee personal information is needed. A general job description can be included if applicable. If there exists some limit for surface contamination, it would be prudent to record that in the notes to the lab. Some ballpark figure is better than none at all.
- Document on the OSHA-91(S) the locations where the wipe samples were performed. Drawing a diagram of the areas where wipe samples are taken can help tremendously. There isn't a lot of room on the OSHA-91(S), so utilize extra sheets if need be. Just remember to add these in with the sampling sheets in the IB section of the case file and not within the Rough Work Notes section.
To Do: Always front-to-back, never back-to-front. Gather the specific steps from the OTM.
To Do: Mimic Lead Wipes below
- There’s a perforated strip at the top of the bag. Remove this when preparing to do the lead wipe.
- After performing the lead wipe, fold the wipe where the wiping surface is on the inside of the fold so as to not leave any remnants on the inside of the bag.
- Fold the yellow strip with the wire over again and again until sufficiently sealed.
- Fold the wires in at the ends to keep it closed.
- Seal with tape across the top / across the fold.
- Wrap horizontally with half the tape sticking above the edge so that the sticky sides will seal together.
- Multiple wraps can be done and is probably best.
- End wrap with enough room to initial over end of strip.