What’s the difference between particulate and particle?

Should it be diesel particulates or diesel particles, and why?

Could you provide three or more examples where it should use particulate rather than particle?

  • What dictionary failed to explain this adequately?
    – tchrist
    Dec 31, 2012 at 0:34
  • For example, M-W says particulate is just minute and separate particles, but AFAICT, all particles are normally minute and separate.
    – qazwsx
    Dec 31, 2012 at 1:11
  • @Problemania: Having looked into it, I don't believe there's any meaningful "reason" for this somewhat peculiar usage, but it seems to me that (possibly for lack of rationale) it'll fade away in another decade or two. I'd stay ahead of the game and avoid noun use of particulate if I were you. Currently it sounds credible in the plural for the general population, but it'll never last once people start asking what exactly a diesel particulate really is. Dec 31, 2012 at 4:56
  • When in doubt, ask around, keep asking until an authentic answer is found, do not speculate.
    – Kris
    Dec 31, 2012 at 7:28
  • 1
    The salient idea in modern usage Is that particulates are formed in the environment through chemical reactions take place in the atmosphere or oceans. These reactions are not restricted to atmospheric combustion products and byproducts. So tires produce rubber dust or particles, not particulates, because the process is mechanical
    – Phil Sweet
    Jan 30, 2018 at 14:12

5 Answers 5


The US Clean Air Act designates six criteria pollutants, for which national ambient air quality standards (NAAQS) have been set: Nitrogen Oxides, Sulfur Dioxide, Lead, Ozone, Carbon Monoxide, and Particulate matter. The EPA and state regulatory agencies throughout the US (and other developed countries) regulate emissions of air pollutants, with special attention paid to the criteria pollutants.

When the topic is air pollution, and especially the regulation of air pollution, the only of the two terms used is particulate. You might use any of the following collocations:

  • diesel particulate emissions
  • particulate matter from diesel combustion/engines
  • diesel particulates

The plural form of particulate matter, (i.e., different types of particulate matter) is particulates. So the term diesel particulates will usually be understood to mean "particulate matter emitted from diesel combustion falling into various size ranges (typically <2.5 microns, and <10 microns, which are regulated categories)."

The phrase diesel particles would mean "a mist of uncombusted diesel fuel".

For further clarity on the usage of particulate, I'll incorporate the full OED entry for the term which contains a large number of examples of its use:

A. adj.
1. Existing in the form of minute separate particles; composed of such particles.

1870 J. B. Sanderson in 12th Rep. Med. Officer Privy Council App. XI. 237 The disease..must obviously be regarded as in the highest degree volatile, if we are to understand the word in its original and every-day signification, as something which is freely wafted by the air. Is it, like the more fixed contagium of cow-pox also particulate?
1882 W. H. Power in Rep. Use Hosp. for Infectious Dis. App. II. 330 Familiar illustration of that conveyance of particulate matter which I am here including in the term ‘dissemination’.
1923 Proc. Royal Soc. 1922–3 A. 102 623 We assume the invisible portion of the cloud to be particulate and not molecular.
1966 McGraw-Hill Encycl. Sci. & Technol. IX. 197/2 Beta rays are particulate radiation consisting of electrons or positrons emitted from a nucleus during β-decay.
1993 R. J. Pond Introd. Engin. Technol. (ed. 2) x. 299 Portland cement concrete is the most common particulate composite.

2. Of or relating to minute separate particles.

1881 Jrnl. Microsc. Sc. Jan. 121 The ingestion of fats in a particulate form by Vertebrata.
1888 Times 20 Jan. 10/2 The particulate and undulatory theories of smell are not exclusive of each other.
1967 Brain 90 695 Note particulate flow (sludging) and stasis in veins and venules.
1988 Notes & Rec. Royal Soc. 42 38 He encouraged to a certain extent the edifying use of the inverse-square law..and even of the particulate theory of matter.
1999 Proc. National Acad. Sci. U.S.A. 96 1916/2 For immunization..protein was either used in native, particulate form..or in denatured form.

3. Genetics. Relating to or designating inheritance in which offspring manifest discrete characters each inherited from one or other of the parents.

1885 F. Galton in Science Sept. 273/1 To express this aspect of inheritance, where particle proceeds from particle, we may conveniently describe it as ‘particulate’.
1889 F. Galton Nat. Inheritance ii. 8 The exact meaning of Particulate Inheritance, namely, that each piece of the new structure is derived from a corresponding piece of some older one.
1930 R. A. Fisher Genetical Theory Nat. Selection i. 8 Apart from dominance and linkage,..all the main characteristics of the Mendelian system flow from assumptions of particulate inheritance of the simplest character.
1971 J. Z. Young Introd. Study Man xxviii. 392 (heading) Genes and their mutations. Particulate inheritance.
1996 Evolution 50 470 Do Dennett's memes..show particulate or blending inheritance?

4. Affecting or limited to certain parts only of a whole. rare.

1920 Public Opinion July 26/1 A social body cannot be making more than particulate progress, if it contains a large proportion of members who do not get a fair chance.

B. n.
A particulate substance, esp. as a contaminant; particulate material.

1949 F. O. Schmitt in A. K. Parpart Chem. & Physiol. Growth 49 The various cytoplasmic particulates such as the microsomes, secretion granules, Nissl substance and so on.
1971 Nature 20 Aug. 553/2 Airborne particulate was collected on 0·45 μm ‘Millipore’ membrane filters.
1988 Q. N. Myrvik & R. S. Weiser Fund. Med. Bacteriol. & Mycol. (ed. 2) xxxii. 468 The term phagocytosis is often used to designate engulfment of particulates by ‘professional phagocytes’.
2002 Imperial Oil Rev. Winter 20/2 It's the suspension of particulates such as smoke, dust and sulphur dioxide in ground-level ozone that causes the respiratory and other problems of ‘smog days’.

  • 2
    This answer gets the key difference: diesel particulates are the results of combustion, such as carbon dust; diesel particles, if someone were to refer to them, would be particles which make up diesel fuel itself.
    – MetaEd
    Dec 31, 2012 at 8:16
  • @MετάEd: Would you therefore say that ices are the results of freezing? I think the primary reason people pluralise diesel particulates isn't because they're intending to speak of the results of multiple combustions. It's because they're mistakenly assuming a particulate is some kind of fancy technical term for (one of) the particular particles produced by any and all diesel combustion. Dec 31, 2012 at 14:09
  • @FumbleFingers I would say ices are the results of freezing when more than one type of ice was in evidence. The context could be multiple freezings, or it could be a single event out of which more than one type of ice develops. But I'm not talking about the plural, above: I'm pointing out that diesel particles does not mean the same thing as diesel particulates (or diesel particulate). One is fuel; the other is byproducts of combustion.
    – MetaEd
    Dec 31, 2012 at 15:30
  • @MετάEd: My point exactly! Unless you're thinking of multiple different and physically separate types of ice, you use the singular. But there's an inherent clash between precise technical usage and common parlance on this one. My guess is it'll be resolved by the former settling on singular mass-noun particulate, and the latter on plural particles. Ordinary people are not about to become seriously clued-up about the distinction you and I are already aware of. Dec 31, 2012 at 16:27
  • +1 for research into diesel particulates. But could anything be said about proper usage of particles vs particulates in other context? Is particulate/particulates used any how in other phrases? If so, what's the key that makes it different from using particle/particles?
    – qazwsx
    Dec 31, 2012 at 17:35

Particulates are things made up of particles. Diesel particulates are made up of particles of various exhaust gases, for instance.

  • So you're saying particulates are composite, and are composed of particles, which are normally smaller?
    – qazwsx
    Dec 31, 2012 at 4:33
  • No, it means just what it says, "Particulates are things made up of particles." Composites and relative sizes do not come into the definition.
    – Kris
    Dec 31, 2012 at 7:26

The phrase you are looking for here is diesel particulates, because that is the normal word used when you are talking about the by-products of combustion and a pollutant. The other does not make sense for this case.

You can have dust particles and subatomic particles, but the stuff that pollutes the air is always fine or coarse particulates.

  • I don't think you really explained why "diesel particulates" "is the normal word used" as opposed to particles. But +1 any way.
    – qazwsx
    Dec 31, 2012 at 4:33
  • @tchrist: I know you'll hate my answer! But even Canute couldn't hold back the tide... Dec 31, 2012 at 4:42

A particle is a small object. A particulate is made of one or more particles either combining to form a particle or created from one or more particles. The definition is simple enough but the usage gets dificult at times.

PARTICLE(S) A drop of diesel contains many diesel particles.

If you spray diesel into the air, some particles of that diesel may combine with particles of other polutants and travel greater distances than the main body of diesel which falls to the ground.

As with water, a particle of diesel is made of atomic elements combined in a secific manner.

PARTICULATE(S) Particulate matter is made of very tiny particles of one or more substances, such as diesel or bacteria.

When burning matter like diesel fuel, the residual side effect contains particulates which may possibly be hazardous to your health.

The particulate created when hydrogen and oxygen are combined, by a specific reaction, is water vapor. A collection of these vapors form particles of the liquid known as water.

Getting carried away with discussions on the particular sizes of particulate matter don't truly help the definitional uses of particles or particulates.

I hope you've found this particle of information more useful than the information distributed here 7 years ago.

  • 1
    Hello, static. You obviously think that this offers something extra to or even better than the accepted answer here. You might be right in thinking that. But look at the way jlovegren adds supporting linked references to his assertions. These are what contribute weightily to a good answer on ELU. Oct 26, 2019 at 15:18

I don't really like to post this, because I've already agreed with and upvoted tchrist's answer, but...

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...which I think suggests the smart money should be on diesel particles. Note that there's not much point in graphing earlier usage - hardly anyone knew/cared/wrote about contaminants in diesel exhaust until the late 70s.

It was used adjectivally (in scientific contexts) a century before OED's first citation of particulate as a noun in 1960. That was the UK-based New Scientist, referring to nucleoproteins, coenzymes and cell particulates. Next they've got Nature (UK/US/global) in 1971 writing of airborne particulate (note the singular form). A few years later it was the word initially dominating usage in relation to diesel particulate (again, primarily as a singular noun, meaning "stuff composed of particles").

I can't explain why particulates started being used for the particles themselves. Perhaps someone thought it was "prestigious/academic". But if that graph trend means anything, I doubt the usage will endure.

EDIT: In light of a few downvotes, I've amended my chart to include the singular form, which has clearly always been more common. I have no problem with that one - it's a natural extension from the long-established adjectival usage to refer to [some] particulate matter as a particulate.

The problem is when people pluralise the term (which is what OP asks about). We don't normally speak of smokes around industrialised urban areas, or say ices are produced when water freezes. When people use the term diesel particulates, they're not normally thinking in terms of many "interdispersed" particulates from many separate instances of combustion - what they have in mind is the billions of tiny particles in the air produced from those sources.

It's true that strictly speaking, diesel particles should mean tiny globules of (unburnt) diesel vapour. Quite possibly some people even think that's what the particulate consists of, I don't know. The point is usages such as small particulates are inherently "strange", since they lead people (including OP) to think particulates are some special kind of small objects suspended in gas/liquid.

Although particulate is currently often as "shorthand" for a particle within a particulate in scietific/industrial contexts, it's actually quite rare to see a single particle referred to as, for example, a large particulate (most examples in that link quite clearly mean particulates made up of (relatively) large particles).

I remain of the belief that technical usage will mainly stick with singular usage as a "mass noun", and popular usage will increasingly adopt diesel particles when they mean "bad stuff in the air caused by diesel combustion". This seems both logical, and consistent with the trends in my graph.

  • So you're suggesting that the usage of particulate is just a meme that happens to spread for no obvious intrinsic merit?
    – qazwsx
    Dec 31, 2012 at 7:00
  • @user1664196: That's an overstatement of what I'm suggesting. But noting that I'm picking up downvotes, perhaps I should amend my graph to show that singular diesel particulate is more common than either plural. Singular is a perfectly sensible use of a particulate (meaning, some matter in particulate form), but the plural form is probably usually being used "incorrectly". Dec 31, 2012 at 14:03

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