We've found it worked best to give volunteers a broad time range for the trials (i.e. drop by anytime between 5 and 9). The process is pretty intensive for the testers, and this way we could test a lot of people without making the volunteers wait around too long. We always provided food and lots of juice and non-alcoholic drinks (we didn't want any alcohol for fear of it blurring the trial results). We also tried as hard as we could to be as appreciative as we could of those being sprayed.
We want to make sure that none of the our volunteers have unexpected reactions to the pepper spray. We want to "do no harm," and we don't have the resources to handle a medical emergency. Therefore, we ask people with the conditions listed below to not participate in the trial. We're also sure to give people plenty of opportunity to bow out gracefully if they decide they don't want to participate.
anyone with a lot of allergies
any condition that compromises the immune system, skin, eyes or respiratory tract like asthma, COPD, excema, conjunctivitis, uveitis
anyone who's pregnant, nursing, or trying to get pregnant.
history of hive-like reactions to poison oak/ivy.
HIV positive (especially symptomatic)
long term Steroids (e.g. prednisone)
immune system blockers/ transplant meds
People are questioned in as private a setting as possible to exclude any of the above named conditions. They will also be asked their age, what gender they identify as, if they smoke and if they'd eaten spicyfood recently (see the write up on the remedies for rationale).
Each subject is matched with a partner subject. This way they have someone to run around the block with, complain with etc. Also we have found that one scribe/interviewer/whatever can record data on 2 people simultaneously.
One tester (the scrubber) will abrade both volunteers' arms with the green side of a scrub pad. We use the relatively hairless palm-side of the forearm. We have one person do all the scrubbing to keep it consistent. Each person gets her own piece of scrub pad to avoid sharing.
Each volunteer will do some exercise to 1) open pores and 2) get her cardiovascular system going at fullspeed. This can be running around the block, push-ups, jumping jacks, whatever the subject wants.
The volunteer then moves to the back yard (down wind of other people, edible plants, etc) where a consistent quantity of capsicum is applied. We aim for, but don't by a long shot always acheve, consistency by 1) using a supply of known capsicum concentration and 2) applying it equally each time.
OC is applied to both forearms. A tester notes the time of capsicum application on the subject's information sheet and the degree of pain (using a 1-10 pain scale) in both arms. After 2-3 minutes, a remedy is applied to the subject's right arm only. We do not tell the subject what the remedy is. We note the time of remedy application on the subject's information sheet as well as their degree of pain in both arms immediately post-application. We hope for a drop in the remedy arm as opposed to the non-remedy arm.
The pain in both arms will be tracked over time and at regular intervals (every 2-3 minutes for the first 10 minutes, then every 5 minutes until 30 minutes post application of remedy, on the subject's information sheet.
Once the subject has passed the 30 minute mark since capsicum application, or if they're in too much pain, or if it just seems like the time is right, we have them wash both arms with soap and water.
The basic protocol is very similar to that of skin testing. The differences are as follows: we seemed to need 2 testers per participant. One to apply the remedies be reassuring, etc and another one to write down the data, remind the applier of the protocol etc. It was much more labor intensive and we tended to wait until the very end of the evening to do these. Therefore they got no partner.
After the screening interview they would run around the block or do other exercise but there was no scraping. An effort was made to cover one eye and the better part of the face (nose, mouth etc). Capsicum is applied to the uncovered eye and surrounding skin. Pain was recorded pre-remedy. The affected eye got treatment at 2-3 minutes post-application, and then several times again if the pain continued. Each subsequent application is noted on the sheet, as well as pain at regular intervals per above. It was difficult to find a control for the eye trials as we're (at this point) unwilling to spray both eyes and leave one untreated .
We tell the volunteer what the remedy was that we used. We tell them about the many other remedies and washing strategies we have available if they're still in pain. We also said we'd call them the next evening and asked them pay attention to how the treated and untreated areas felt through the night.
The next evening we tried to call to assess continuing discomfort throughout that night. If they were uncomfortable we ask how bad it was on the 1-10 scale and if it woke them during the night. For skin subjects, was the discomfort equal on both arms or better in thetreated arm? For eye subjects, how did their face feel and how does it feel now?