hydrogen sulphide
B2/C1Technical/Scientific
Definition
Meaning
A colourless, toxic gas with a strong, unpleasant smell of rotten eggs, with the chemical formula H₂S.
A naturally occurring compound formed by the anaerobic bacterial decomposition of organic matter. It is also produced industrially as a by-product and is a significant hazard in industries like oil and gas, wastewater treatment, and mining. It is a weak acid when dissolved in water.
Linguistics
Semantic Notes
Primarily a scientific and industrial safety term. In everyday contexts, people often describe the smell without naming the compound (e.g., 'It smells like rotten eggs'). The spelling 'sulphide' (British) and 'sulfide' (American) is the main variation.
Dialectal Variation
British vs American Usage
Differences
Spelling: 'hydrogen sulphide' (UK) vs. 'hydrogen sulfide' (US). Pronunciation of the 'ph'/'f' syllable also follows suit.
Connotations
Identical technical and safety connotations in both varieties.
Frequency
Equally frequent in relevant technical/safety contexts in both regions. The UK spelling with 'ph' is increasingly seen in international scientific publications due to historical convention.
Vocabulary
Collocations
Grammar
Valency Patterns
[Hydrogen sulphide] + [verb] (e.g., forms, leaks, accumulates)[Verb] + [hydrogen sulphide] (e.g., detect, produce, release)[Adjective] + [hydrogen sulphide] (e.g., toxic hydrogen sulphide)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None directly. Conceptually linked to 'a rotten egg smell'.”
Usage
Context Usage
Business
Discussed in risk assessments, safety reports, and environmental compliance documents for relevant industries.
Academic
Common in chemistry, geology, environmental science, and biology papers discussing anaerobic processes or pollution.
Everyday
Rarely used by name. Typically: 'There's a smell of rotten eggs/sewer gas.'
Technical
Central term in occupational safety, chemical engineering, petrochemical refining, and wastewater management.
Examples
By Part of Speech
verb
British English
- The organic matter began to hydrogen-sulphidise under anaerobic conditions.
American English
- The sludge hydrogen-sulfidised in the tank.
adverb
British English
- The gas smelled hydrogen-sulphide-ly pungent.
American English
- The gas smelled hydrogen-sulfide-ly pungent.
adjective
British English
- The hydrogen-sulphide-rich atmosphere was immediately evacuated.
American English
- The hydrogen-sulfide-rich atmosphere was immediately evacuated.
Examples
By CEFR Level
- This bad smell is like hydrogen sulphide.
- Hydrogen sulphide is the gas that smells like rotten eggs.
- Workers must wear monitors to detect dangerous levels of hydrogen sulphide in the refinery.
- The biogeochemical cycling of sulfur involves the anaerobic production of hydrogen sulphide by sulfate-reducing bacteria in sediments.
Learning
Memory Aids
Mnemonic
Remember the 'HYDRO-' (water-related) part is in 'hydrogen', and the 'SULPH-' (related to sulfur, which smells) is in 'sulphide'. Think: 'HYDROgen from SULPhur gives a rotten smell inside.'
Conceptual Metaphor
POISON/DEATH (due to high toxicity), DECAY (due to association with rotting organic matter), HIDDEN DANGER (colourless, can overcome senses).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Direct calque 'водородный сульфид' is correct but formal. The simpler term 'сероводород' is the standard, universal term in Russian (literally 'sulfur-hydrogen'). Do not translate it word-for-word as 'водородная сера'.
Common Mistakes
- Misspelling: 'hydrogen sulphate' (which is H₂SO₄, sulfuric acid).
- Confusing it with other sulfur gases like sulfur dioxide (SO₂).
- Incorrect pronunciation stress: /haɪ.'dro.dʒən/ not /'haɪ.drə.gen/.
Practice
Quiz
What is the primary safety concern associated with hydrogen sulphide at high concentrations?
FAQ
Frequently Asked Questions
Yes, hydrogen sulphide is highly flammable and can form explosive mixtures with air.
It is highly toxic. At low concentrations, it irritates the eyes and respiratory tract. At higher concentrations, it quickly deadens the sense of smell and can cause respiratory paralysis, leading to death.
It is found in volcanic gases, natural gas deposits, hot springs, and is produced during the bacterial breakdown of organic matter in environments without oxygen, such as swamps, sewers, and manure pits.
A 'sulphide' (e.g., H₂S) is a compound containing sulfur in a lower oxidation state, often associated with a 'rotten egg' smell. A 'sulphate' (e.g., H₂SO₄, sulfuric acid) contains sulfur in a higher oxidation state and is a different, typically non-gaseous, compound.