Material guide: triethyl citrate (TEC) — not a fragrance material, and the bottle you will empty fastest

Short version: eighty-four entries in, this is the first one that is not a fragrance material. Nine tenths of every dilution you own is this or something like it, and nobody writes about it.

The fields

Field	Value
CAS	77-93-0
Formula	C12H20O7, MW 276.29
Database category	Carrier solvents/diluents for flavors and/or fragrances
Appearance	Colorless clear oily liquid (est)
Melting point	−46 °C
Boiling point	127 °C @ 1 mmHg
Flash point	118 °C
Specific gravity	1.135–1.139 @ 25 °C
logP	0.10 (est)
Water solubility	6.5 g per 100 mL water
Odour strength	None
Odour description	At 100%: odorless to mild fruity wine
Substantivity	216 hours
Shelf life	24 months
Suppliers	54
Regulatory	JECFA 629, FEMA GRAS 3083, CoE 11762, FLAVIS 09.512, food additive E1505
Cosmetic uses	Antioxidants, deodorants, fragrance, plasticisers, solvents
GHS	H332 harmful if inhaled
Natural occurrence	Cabbage, white wine

Why this one, this round

Someone posted a photo of an orris butter at 10% in TEC, saying it looked too thick, and added this:

"But don't own TEC or other materials diluted in TEC, so I thought maybe TEC is quite thick as well."

A reasonable guess, and cleanly wrong. TEC melts at −46 °C. It is a liquid at any room temperature a person can occupy, with a viscosity in the ordinary oily-liquid range.

The thick thing is the orris butter. In the same database, Iris pallida orris rhizome concrete butter melts at 40–46 °C and reads "pale yellow to yellow paste". A 2018 GC-MS analysis gives the reason: that rhizome oil is 56% myristic acid, 15.42% lauric acid, 14.50% capric acid — 86% solid saturated fatty acids. "Butter" in the name is literal.

A 10% solid dissolved in 90% liquid still looks thick. That is not the solvent's doing.

"Strength: none" does not mean odourless

This field is worth reading carefully, because it decides whether your own diluent fools you.

The strength field says none. But the odour description field (Luebke, tgsc, 1981) says:

At 100%: odorless to mild fruity wine

And the taste description field is more explicit: fruity, medicinal, floral, bitter.

"Odorless to mild" is not "odourless". It is a range, and the far end of the range has a smell. Two consequences:

1. Ninety per cent of what you smell in a 10% dilution is the solvent. If that solvent carries a trace of fruity wine, you are smelling it under every material you evaluate.
2. Its substantivity field reads 216 hours. The database gives nine days of substantivity to something classified as a solvent. I do not know how that was measured — how do you measure substantivity for something rated "none" in strength? — but at minimum it warns you that TEC does not leave a smelling strip in a couple of hours. When you are reading the drydown, it is still on the paper.

This is why many people keep a solvent-only blank strip during evaluation. This series has written before about fields where the number is present and the method is not; this one belongs in that category.

What separates it from DPG is polarity

The two common diluents in perfumery are DPG (dipropylene glycol) and TEC, and they are not interchangeable.

	TEC	DPG
Molecular weight	276.29	134.17
logP	0.10	−0.60
Specific gravity	1.135–1.139	1.019–1.021
Melting point	−46 °C	Boiling point 230–231 °C
Appearances in the corpus	5	445

logP 0.10 means it sits almost neutrally between oil and water; DPG is more hydrophilic. In practice:

• TEC dissolves lipophilic resins, concretes and large molecules better than DPG. Orris butter, benzoin and olibanum resinoid are usually diluted in TEC or benzyl benzoate rather than DPG. That is why the person on the forum received "10% in TEC" and not "10% in DPG".
• Specific gravity 1.135 is heavier than water. It sinks when mixed, so insufficient stirring shows as layering.
• Water solubility of 6.5 g per 100 mL is high for a diluent. If your finished product goes into an aqueous system, this field starts to matter.

But the corpus numbers are blunt: across 954 formulas, DPG appears as a standalone entry 445 times and TEC 5 times. That does not mean TEC is little used; it means published formula authors default to DPG. TEC shows up when the material demands it.

Incidentally, of the corpus's 17,481 material entries, 2,179 (12.5%) carry a percentage in the name — one entry in eight is a dilution. Diluents are invisible in a formula and never invisible in a bottle.

It is not only a diluent

The database's cosmetic uses field lists five: antioxidants, deodorants, fragrance, plasticisers, solvents.

The notes field is clearer:

"Used in foods as a flavouring agent, solvent and surface-active agent. Triethyl citrate is an ester of citric acid. It is a colorless, odorless liquid used as a food additive (E number E1505) to stabilize foams, especially as whipping aid for egg white. In pharmaceutical coatings and plastics."

A whipping aid for egg white. The liquid you dilute fragrance materials in is the same thing a bakery uses to stabilise meringue. It is also a plasticiser for tablet coatings — one of the papers the record cites measures how plasticiser level affects the breaking force of extended-release tablets.

One practical implication for perfumery follows. Grades differ. The record lists "grades: technical; refined; fcc". Technical and food grade carry different impurities, and what you are making goes on skin and has to be smelled. Checking the grade when buying a diluent matters as much as it does when buying a fragrance material, and almost nobody says so.

That GHS line

TEC's GHS classification is a single line: H332 harmful if inhaled (acute toxicity, inhalation, Category 4).

Read it in the right context. The inhalation toxicity field gives rat LC50 1300 ppm/6H, with dyspnea, acute pulmonary edema and pleural effusion. That is animals held in high vapour concentrations for six continuous hours.

Its oral and dermal toxicity are both low: oral rat LD50 5900–7000 mg/kg, dermal rabbit LD50 > 5000 mg/kg. Being a food additive says something about the margin on oral exposure by itself.

What to watch in practice is ventilation, not contact. The GHS precautionary statements are P261 "avoid breathing vapours/spray" and P271 "use only outdoors or in a well-ventilated area". If you are doing bulk dilutions in a small room and spray-testing, that classification is written for that situation, not for touching it.

Whether to use it

• When you need to dissolve lipophilic resins, concretes and absolutes, TEC beats DPG. Orris butter, benzoin and olibanum resinoid are the type cases.
• But the corpus default is DPG (445 to 5). If you want to line up with published formulas, DPG is the common language.
• It is not fully odourless. Keep a solvent-only blank strip when evaluating.
• Check the grade when buying. Technical, refined and FCC are different things.
• Ventilate. The one GHS line is about inhalation.
• It is heavier than water and sinks. Shake it properly after mixing.

What this doesn't establish

• I do not know where the 216-hour substantivity figure comes from. The record does not explain how substantivity is measured for a material rated "none" in strength. It is listed because it is in the field, not because I can account for it.
• The DPG figures come from the database's dipropylene glycol (#13450) record (updated 28 August 2026; estimates were used originally). The subject here is TEC; the DPG column is only for scale.
• The corpus count of 5 for TEC against 445 for DPG counts standalone entries, not actual usage. Most dilutions are written as "material name + 10%", with the solvent unrecorded.
• Neither cited paper is about TEC. Mykhailenko 2018 is an iris composition analysis, used to explain why the thick thing is the orris butter and not the TEC. Dalton 2000 is the olfactory adaptation review shared with this round's beginner article. TEC's own PubMed literature sits almost entirely in pharmaceutics (tablet-coating plasticiser) and food science, unrelated to perfumery, so I have not cited it.
• I have not tested the grade differences. The distinction between technical and FCC grade impurities is one line in the record and I did not pursue it further.