Local Odor Vocab

Curren's SCAQMD Urban Odor Dictionary

link to google fusion graph

You’re looking at a smell network based on the work of UCLA post-grad named Jane Curren. She took all the words used in odor complaints in southern California, and found the source of those complaints. These odor sources can be anything from a hidden garbage dump to a local restaurant. The size of the blue nodes doesn’t indicate smelliness; it indicates more descriptors. Restaurants have more descriptors because they have 1. More people near them and 2. A greater diversity of things that smell. (I’m guessing this.) What this chart does show is the most common odor complaints in the middle of the cluster – we smell burnt things a lot. Also rotten eggs/sulfur/natural gas.

Below, Curren went further and found the specific chemical source of these smells, and I listed them below. Next time you smell something funny, check this list. (And the next time you’re in New Jersey, take a tour of the New Jersey Turnpike mobile museum of olfactory delights, you’ll smell firsthand many of the odors on this list!)

Curren's Urban Odor Lexicon

               

Descriptor                           Odorant

solvent                                 2-butanone

petroleum                          2-methyl-1-propene

pungent                               2-pentanone

sweet                                   2-pentanone

lemon                                   acetaldehyde

alcohol                                  acetaldehyde

acrid                                      acrolein

pungent                               ammonia

sweet solvent                   benzene

sweet                                   dichloromethane

decayed cabbage             ethyl mercaptan

pungent                               formaldehyde

rotten egg                           hydrogen sulfide

woody                                  m-cresol

resinous                               m-cresol

medical                                                m-cresol

woody                                  o-cresol

resinous                               o-cresol

medical                                                o-cresol

woody                                  p-cresol

resinous                               p-cresol

medical                                                p-cresol

medical                                                phenol

sweet                                   phenol

irritating                               propanal

fruity                                     propanal

empyreumatic                  pyridinec

irritating                               sulfurdioxide

aromatic                              toluenec

fishy                                      trimethylamine

pungent                               trimethylamine

sweet                                   acetone

minty                                    acetone

sweet solvent                   benzene

woody                                  cresol

resinous                               cresol

medicinal                             cresol

sour                                       dimethyl disulfide

onion                                    dimethyl disulfide

decayed cabbage             dimethyl sulfide

decayed cabbage             ethyl mercaptan

garlic                                      ethyl mercaptan

aromatic                              ethylbenzene

pungent                               formaldehyde

rotten eggs                         hydrogen sulfide

skunk                                    i-propyl mercaptan

sour                                       methyl mercaptan

garlic                                      methyl mercaptan

decayed cabbage             methyl mercaptan

skunk                                    n-butyl mercaptan

skunk                                    n-propyl mercaptan

medicinal                             phenol

sweet                                   phenol

irritating                               propanal

sweet                                   p-xylene

sharp                                     thiophene

skunk                                    thiophene

rubber                                  toluene

moth balls                           toluene

aromatic                              1,2,4-trimethylbenzene

aromatic                              1,3,5-trimethylbenzene

vinegar                                 acetic acid

sour                                       acetic acid

chemical                              acetone

sweet                                   acetone

acrid                                      acrolien

pungent                               ammonia

sweet                                   a-pinene

pine                                       a-pinene

sweet solvent                   benzene

malty                                     butanal

burnt                                     butanal

rancid                                    butyric acid

sour                                       butyric acid

perspiration                       butyric acid

fruity                                     butyl acetate

dead body                          cadaverine

disagreeable sweet        carbon disulfide

almond                                 chlorobenzene

sweet                                   chloroform

ethereal                               chloroform

pungent                               crotonaledehyde

gasoline                               decane

ethereal                               dichloromethane

sour                                       dimethyl disulfide

onion                                    dimethyl disulfide

decaying vegetation       dimethyl sulfide

aromatic                              ethylbenzene

oily                                         heptanal

musty                                   heptanal

woody                                  heptanal

fatty                                      hexanal

green                                    hexanal

rotten egg                           hydrogen sulfide

sharp                                     isopropyl benzene

aromatic                              isopropyl benzene

sharp                                     cumene

aromatic                              cumene

lemon                                   limonene

decayed cabbage             methyl mercaptan

moth balls                           naphthalene

tar                                          naphthalene

sweet                                   m-xylene

gasoline                               octane

sweet                                   o-xylene

pungent                               pentanal

sharp                                     propanal

vinegar                                 propanoic acid

sour                                       propanoic acid

sweet                                   p-xylene

solvent                                 styrene

rubber                                  styrene

sweet                                   tetrachloroethene

rubber                                  toluene

moth balls                           toluene

sweet                                   tricholoroethane

fishy                                      trimethylamine

fecal                                      valeric acid

sour                                       valeric acid

sweet                                   vinyl acetate

Suffet and Rosenfeld's Urban Odor Lexicon

*much of Curren’s work came from Suffet and Rosenfeld, so I added their leftover terms here

Descriptor                           Odorant

Coffee                                  Furfruryl Thiopropionate

earthy                                   Geosmin

musty                                   2-Methyl isoborneol

moldy                                   2,4,6-Trichloroanisole

grassy                                   Cis-3-hexen-1-ol

dead animal                       Putresine

rotten vegetable              Dimethyl Trisulfide

fishy                                      Dimethyl Amine

fishy                                      Methyl Amine

plastic                                   Methyl Methacrylate

fecal                                      Indole

manure                                  Skatole

burnt                                     Guiaicol

Primary document: Curren, J. 2012. Characterization of Odor Nuisance. UCLA.

http://www.wcsawma.org/wp-content/uploads/2012/11/JMC-dissertation.pdf

Supporting document: Suffet, I.H., and P.E. Rosenfeld (2007). The Anatomy of Odour Wheels for Odors of Drinking Water, Wastewater, Compost and the Urban Environment, Water Science and Technology 55(5), 335-344.

Research note: The descriptor names come from the above source and supporting documents, whereas the odor causing compounds were matched against varying sources which will not be listed here; see instead the source document for those references

Firmenich and the Ecstasy of Saint Theresa

Secrecy. That’s a really important thing about the flavor and fragrance industry. Funny how New Jersey has to be the global capital of this industry, a state which is more commonly known as the dirty-money mafia capital where people get mysteriously buried in concrete. No relation though, just coincidence. In fact, I’m not sure how New Jersey came to be the flavor and fragrance capital of the world, but it is. More than half the world’s ingredients come from a small strip of this small state. At least one of those ingredients, Hedione, which we’ll describe in a moment, is produced exclusively here in NJ, and is part of 95% of all consumer products, globally, that have flavoring or fragrance added.

Hedione is produced by Firmenich, the biggest flavor and fragrance company there is. I went there today as part of an occupational health and safety class where we visit real sites and check out their digs. They brainwash us afterwards, like the men-in-black thing.

Firmenich, the facility that actually makes the ingredients, is in Newark. They have other locations. Our contact says “we also have R&D labs all over the place, but they’re very non-descript; you would never notice; nobody knows where they are; I don’t even know where they are.”  Again, that’s how fragrance works.*

They mostly make chemical ingredients, but they also do a little bit of research here, and these special folks are called Noses. If you work here, I don’t care if you’re a truck driver (I think they contract those guys out, actually) you can be a nose. Noses, from what I understand, are people who can smell pretty good. But they’re also people who can smell Hedione. Apparently, and I feel I should know more about this, but our contact tells us that only 2% of the population can really smell Hedione. Therefore, if you work for this facility, and you can smell it, your job is to, once in a while, sniff a batch and make sure it’s ok for use. Reminder – there is no electronic nose that can do this, only humans can tell if a smell is “good for use.”

If you’re a bit confused, you should be. I just said that Hedione is used in 95% of all products, but only 2% can smell it. ??? Well, after a bit of poking around, particularly my most favorite site for checking this kind of stuff, Perfume Shrine, I can say this – it seems like you can’t actually smell Hedione, but you can, at the same time. You can tell when it’s not there, and you can sense that a fragrance has something special in it when it’s present, but when isolated, you can’t smell anything.

Let’s just say that Hedione is absolutely critical for perfumery, and Firmenich has the market cornered. I thought about that as I sat in the presentation room, listening to our contact, smelling the warm, tangy, rough-spicy hint of my Italian Cypress creeping to my noseholes. Those molecules in my perfume came from this factory.

 

Ecstasy of St. Theresa, Bernini, 1650

We leave the presentation room and begin our tour. We walk inside one of the reactor pads where they turn raw ingredient-chemicals into fragrance industry components. It’s a huge building, and the equipment rises far above our heads. It looks like what you would expect – a big, metal, cylindrical reactor vessel, braced on all sides like the Eiffel Tower, penetrated by myriad hoses and gauges and pressure relief valves. The floors dusty concrete with long drainage grates running along the length of them. It’s not so big in terms of its footprint, but it goes up forever, and it’s ominous.

“This reactor is for Hedione. Strictly Hedione.” Other ones are used for different things, depending, but this one is dedicated. I smell something. If it’s not Hedione, well, I don’t know what the hell it is, because I may be smelling a thousand different things right now. And speaking of now, this post isn’t about Hedione, or secrecy in the perfume industry; it’s about what happens next.

Ecstasy of St. Theresa, Bernini, 1650, detail

We leave the Hedione reactor and go next door to another pad that processes a bunch of chemical ingredients all in the same building. Limonene, Citronellol, Geraniol, Linalool, the list keeps going. Same ominous, towering vats, hoses and pressure valves, metal and concrete and warning signs. After about five seconds of standing there, I was overcome with what I can only call the scariest thing I have ever smelled.

Now, I’m not even sure what that means, because how can a smell be scary?

I mean, I know we can “smell” fear, but that’s not what I’m talking about. You look at these pictures from the Renaissance, for example, religious pictures of people shielding their eyes from God – he’s so powerful they can’t even look at him. Your eyes can’t see something that powerful.

That is not to say that in this place it smelled bad, like the kind of smell that makes you twist your head backwards. It smelled scary. It smelled like something I could never understand. It smelled like omnipotence, and I was paralyzed.

I’m sure it was my brain doing this to me, at least a little. I knew that I was smelling a total mélange of the most complex proportions and in very stiff concentrations; I know that by the time you mix more than three or four chemicals together, your brain can no longer tell the difference between them. (So do I really know, from a sensory perspective, that this thing I smell is made of so many different chemicals?)

Nonetheless, there I stood, for the first time noticing that this room is well over one hundred feet tall, such that I cannot see the top of the reactor. And the smell that is both accidentally and purposefully leaking out of it is the scariest thing I have ever smelled. Our contact is talking to us; I can’t hear a thing he says, and I can’t move.

I was stuck so still that I could feel my skull moving involuntarily inside the flesh of my face, and trying not to, and the space between my bones and my flesh tingled with fear and paralysis. This is, to my imagination, what it would be like to “see God.” I’m not so much a religious guy, so I don’t really know what I mean by this, I have heard people say things like this, at least when I studied art history and the Renaissance and philosophy and Aquinas etc. I have heard people talk about seeing God and wondered what they meant by that. I’m too visually jaded to imagine what that would mean, to “see God.”

I was an art teacher for 10 years and an art history major prior to that, so my visual cortex is a post-modern mess that has no place for God, that’s for sure. But that smell…It was so big, so complex, so beyond my capacity for perception, for understanding it, and it was like – although it was beyond my ability to perceive it, I could perceive that. I could comprehend it only so much as to know that it was beyond my comprehension.

There was a very sure, very palpable sense that there was something out there, something in that room, surrounding me, entering my body in fact, stimulating the neurons on the outside of my blood-brain barrier, something that I could not see. How do you know that you’re facing something that you can’t know?

Maybe it was the size of that reactor. I’ve seen stuff like this on tv, but this is the first time we’re visiting a ‘real factory’ and the first time I’ve been in front of something like this. And anywhere else, their massive reactor would smell too. But it wouldn’t smell like this. There was something tremendous about this, something totally incapacitating; it smelled like omniscience.

I’m still getting over it. I didn’t notice until I was driving home that I smelled like a thousand different things. All by myself in my car, with every breath I took, I smelled something completely different in turn: a warm note, a spicy note, a grapefruit, powdery incense, bubblegum, cold metal, the smell of the ocean, flowers of a dozen different kinds, one after another as I breathe again and again. This continued for the rest of the ride home, every breath, another facet of that thing I couldn't perceive in its totality, now came to me one piece at a time.

POST SCRIPT

I write a bit about why the fragrance industry operates in airtight secrecy here, tdlr – it’s because copyright, that’s why, or rather lack of copyright for arts related to both fashion and fragrance.

There’s other reasons too, reasons which even I would rather not mention, but I will: the general public is a bit paranoid when it comes to “chemicals” (did you just get chills up your spine when I said that?) and so if I was the fragrance industry, I think I would do the same; just keep things as quiet as possible.

The Fragrance Industry Speaks

On a sort of side note (this is the post script already, after all) – notice how perfumes have a list of chemicals on them. There’s a governing body that requires them to do that. Every year, a bunch of chemicals are decided to be dangerous enough that they should be listed on the bottle. Others are decided so dangerous they can no longer be used at all, requiring constant reformulations of your favorite scents. The thing is, when you see this list of chemicals, you think, ‘this is what’s in this bottle, this is what makes this thing smell like it does,’ but there’s hundreds of chemicals in there, hundreds. And the ones listed are only the ones that have to be listed. If you really look, it’s like every perfume is made of the same chemicals. That’s because a lot of the same ones are used in everything, just in different amounts, and with little tweaks here and there.

See the International Fragrance Association; they make the safety standards and say which chemicals are safe or are no longer safe for use. They are hated by perfume enthusiasts because they forbid chemicals, requiring reformulations of favorite and legendary perfumes. They are fodder for chemophobes who think the world has organized a systematic slaughtering of the population via slow, chemical carcinogenesis.

And then there’s this little something, about New Jersey, my most popular post to date:

What Exit - The Smells of the New Jersey Turnpike