When is it chemical toxicity or chemical's toxicity?

I think both words mean the same. Is there any difference between them?

For example,

From studies in animals, however, it became clear that the amount of soluble uranium salts depositing and remaining in the lung or bone would never constitute a sufficient radiation hazard to override the chemical toxicity to the kidney.


When dealing with a chemical's toxicity, the exposure statement incorporates criteria values for the statistics relating to risk of ill-health (or death) included in uncertainty factors and/or decisions on the acceptability of the ‘margin of exposure” (see Chapter 8).


An outline of a Toxicity Summary is shown in Fig. 1. Figure 1A involves the chemical's identity, including CAS number, chemical name, trade names or synonyms, and physical properties. The data on the chemical's toxicity then are grouped by acute affects, subacute or subchronic effects, long-term effects other than cancer, …

I have seen both types but I think why a number of them do not have apostrophe. When is the possessive apostrophe necessary?

Sources: Chemical Toxicity ScienceDirect.com
Toxicity and Risk: Context, Principles and Practice
Hazard Communication, Issues and Implementation: A Symposium

  • The only occurrence of the Saxon genitive with chemical on the webpage you linked to is a reference to a chemical's mode of action, but chemical toxicity occurs a dozen times with no apostrophe, as is normal. Commented Oct 31, 2023 at 12:37
  • ...and the reason that particular instance uses the Saxon genitive is that the compound noun phrase a chemical's mode of action appears within a "higher level" list of noun phrases (together with the available mechanistic information and body burdens and vulnerabilities of the populations), and when a list of nouns gets that long, we naturally try to use the shortest phrasing for each individual element (the form as actually used is obviously shorter than the alternative the mode of action of a chemical). Commented Oct 31, 2023 at 12:44
  • In the linked example "chemical toxicity" is a compound noun. It's not talking about toxicity of a particular chemical/compound, but the about the chemical toxicity of uranium compounds in general. In the linked text, you wouldn't be able to replace it with "chemical's toxicity". This would only work if talking about a particular chemical's toxicity.
    – Billy Kerr
    Commented Oct 31, 2023 at 14:28
  • Chemical toxicity might be, in the case of uranium, usefully distinguished from its possible radiological toxicity (also radiotoxicity). Marie Curie's case is worth considering if you plan to fool around with that element. Commented Oct 31, 2023 at 14:42
  • They are most definitely not the same. One is about a chemical and the other is about the subject matter.
    – Lambie
    Commented Oct 31, 2023 at 14:55

2 Answers 2


The apostrophe indicates possession so, chemical's toxicity is referring to a specific chemical which would be mentioned in the context in which this phrase is found. "Chemical toxicity" does not imply a specific chemical and might be a sub-section title is some government environmental impact report.

  • Uranium and some other elements have two kinds of toxicity - radiologic and chemical. Commented Oct 31, 2023 at 19:02
  • @MichaelHarvey this should be expanded and made into an answer.
    – Peter
    Commented Dec 1, 2023 at 2:26

PLURAL. possessive:

There is a significant lack of health and safety information on most chemicals in the marketplace. The U.S. Environmental Protection Agency’s (EPA) chemical inventory includes nearly 85,000 chemicals available for use in the United States (U.S. EPA 2014j), yet only a small subset of these chemicals has been sufficiently characterized in order to draw conclusions about the chemicals’ toxicity for regulatory decision making (Judson et al. 2009; Landrigan and Goldman 2014). chemical

SINGULAR, possessive, here arsenic:

When the Environmental Protection Agency (EPA) crafts a regulatory standard—how much arsenic is safe in drinking water, for example—its staff members rely on scientific assessments of the chemical's toxicity. The quality of these agency reviews have been criticized by industry and on Capitol Hill—criticisms that were backed up earlier this year in a study by the National Academies' National Research Council (NRC). Now Congress has directed EPA to document improvements to the process and to ask the academies to review up to three of its toxicity assessments. the chemical's toxicity

In GENERAL for a particular chemical, possessive, with the determiner a:

For example, the assessment of a chemical's toxicity requires data from experiments involving various doses and treatment durations and, in some studies, simultaneously applying several assay platforms.
a chemical's toxicity

The idea: chemical toxicity, the field or subject matter, used on its own with no determiner:

In this commentary, we shall discuss the recent evolution in computational methods used to predict chemical toxicity.
chemical toxicity

Please note: One can always take a subject matter like chemical toxicity and add something to it: The chemical toxicity of [some thing] has already been shown.

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