Most of what I could write about running a smell session is technique: how to build a palette, how to pace, how to hold the room. This is not that. This is the part underneath the technique, the part that decides whether the work is something done with a person or something done to them. I think about it more than any other aspect of the practice, partly because so much of my work happens in vulnerable contexts where the usual scaffolding of consent does not hold up cleanly, and where the person in front of me may not be able to advocate for themselves in the way the consent forms or a regular fragrance workshop setting assume.
So this is a working ethics. Not a code I was handed, but the set of commitments the practice has resolved toward after a few hundred sessions.
Start by being honest about the power in the room
A smell session is not neutral. I choose the materials, I set the pace, I decide when something starts and stops, and I usually know more about what is about to happen than the person experiencing it. This is an asymmetry and point of an ethical stance here is not to erase the power difference (you can't), it is to handle it honestly and keep handing as much of it back to the participant as the situation allows.
This matters more, not less, when the participant is cognitively impaired, institutionalized, or otherwise in a setting where compliance is the path of least resistance. People in care settings are practiced at going along with things. A nod is not always a yes. Which is the whole reason the rest of this document exists.
Consent is an ongoing process
The biggest mistake people make is treating consent as a gate you pass through once at the start. In the populations I work with, that model collapses immediately, and the research ethics literature on this is actually clear and useful, so I lean on it rather than improvising.
A few principles I take directly from how consent is handled in dementia research, because they are more thorough than anything I would invent.
A diagnosis is not the same as incapacity. This is the single most important and best-established point in the consent literature: a person having a diagnosis does not by itself mean a person can't consent. Capacity is specific to the task and the moment, and many people with mild impairment can consent perfectly well to something as low-risk as smelling a few materials. The default is to ask the person directly, in language and a format they can actually engage with.
When the person can't give full informed consent, you get proxy consent and ongoing assent. Proxy consent is not a permission slip that overrides the person in front of you. You still need the participant's ongoing assent: their moment-to-moment willingness, expressed however they express things.
Dissent overrides everything. This is the cornerstone, and it is a standard in research ethics with vulnerable populations: any sign of distress, refusal, or unwillingness, at any moment, is treated as withdrawal and honored immediately, even if a proxy consented, even if you think the person would benefit, even if you are "almost done." There is no appeal.
Assent has to be re-read continuously. Capacity and willingness will fluctuate. Therefore, consent is not checked once but monitored the whole way through, with active reassessment whenever something shifts. Practically, this means I am never just running my plan. I am reading (or trying to read) the person continuously and treating my plan as the thing that yields.
Reading the body, because the words may not come
Smell is one of the most potent and involuntary trauma triggers there is. A previously neutral odor that was present during a traumatic event can become a conditioned cue, and encountering it later can produce an involuntary intrusion or flashback, a full-body re-experiencing. Studies of traumatic memory find that odors are part of the memory a striking proportion of the time. And the response often doesn't look like a person saying "please stop." From the outside it can look like freezing, a startle, sudden withdrawal, going quiet, a change in breathing. The person may not be able to narrate what is happening while being inside it.
You cannot rely on verbal refusal as your only stop signal. If you wait for someone to tell you they are in distress, you will miss the people most at risk, because the very thing being triggered can take their words away. Tightening, flinching, breath changes, a face that closes, a person who was present suddenly going somewhere else: all of these are withdrawal, and all of them are honored the same way an explicit "stop" would be.
Two practices follow from this. First, I never assume a smell is safe because it is pleasant or innocuous to most people. Second, I keep the exits genuinely available: the person can stop, move away, hand the material back, or simply decline, and that has to be a real and easy option, not one that costs them anything socially. In a setting where people are habituated to compliance, making refusal easy and cost-free is something you have to actively engineer.
My own non-negotiables (these are mine, not borrowed)
Beyond the formal ethics, there are commitments specific to how I think this work should go. I hold these as line-in-the-sand, and I will own that they are my position rather than a consensus standard:
I don't tell people what to feel. I withhold interpretation. The moment I say "this is calming" or "this should bring back good memories," I have overwritten their experience with mine and turned an encounter into a suggestion. Their response, including confusion, dislike, or something they can't explain, is the point. This is also more honest to how smell works: the response arrives before, and partly independent of, the naming.
I don't smuggle in an agenda. I am not there to relax anyone into compliance, to extract a memory for someone else's benefit, or to produce a moving moment for an audience. If a family member or a staff member wants me to "get her to remember the bakery," I won't run the session as a retrieval mission. The encounter belongs to the participant, not to the people watching it.
I don't perform the person's response for others. In group settings there are often observers. It is easy, and tempting, to narrate what is happening, which both interprets for the person and turns them into a spectacle. The person's experience is theirs to keep.
I would rather end early than push for a result. A session that stops short because someone was done is a success. A session that got the planned arc but rolled over someone's hesitation to do it is a failure, even if it looked beautiful from outside.
After: don't leave someone open
Smell can crack things open fast. Ethically, you don't get to open something and walk away. That means leaving time at the end to come back to the room, not scheduling sessions so tightly that someone is hustled out mid-feeling, and noticing when something has surfaced that's bigger than the session. I am not a therapist and I don't pretend the session is therapy. Part of the ethics is knowing the edge of my role and, when something larger surfaces, making sure the person is not left holding it alone and looping in the people who are equipped, with the participant's knowledge and consent.
The short version
If I had to compress all of it: the person in front of you is not a body you are dosing, and not material for someone else's meaning. They are the one having the experience, and your entire job is to keep returning the authorship of that experience to them, through consent you keep re-asking, through dissent you honor instantly, through a body you read continuously because the words may not come, and through the discipline of not telling them what just happened inside them.
The technique is learnable in an afternoon. This part takes longer, and it is the only part that actually matters.
