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Aromatherapy Final Exam Prep 2026 — 100 Questions
with Complete Solutions
SECTION 1: ESSENTIAL OIL CHEMISTRY (15 Questions)
Q1: Which chemical family found in essential oils is known for its calming and antispasmodic
properties, is generally considered safe, and includes linalyl acetate (lavender) and geranyl
acetate (geranium)?
A. Monoterpenes
B. Esters [CORRECT]
C. Phenols
D. Ketones
Correct Answer: B
Rationale: Correct because esters (linalyl acetate, geranyl acetate, benzyl acetate) have
calming, balancing, antispasmodic, and antifungal properties with low dermal irritation risk.
Q2: A client with epilepsy requests an essential oil blend for stress relief. Which oil should be
avoided due to its neurotoxic ketone content (thujone)?
A. Lavender (Lavandula angustifolia)
B. Roman chamomile (Chamaemelum nobile)
C. Hyssop (Hyssopus officinalis) [CORRECT]
D. Frankincense (Boswellia carterii)
Correct Answer: C
Rationale: Correct because hyssop contains ketones including thujone, which is neurotoxic
and potentially convulsant; contraindicated in epilepsy.
Q3: Which chemical constituent is the primary contributor to the expectorant and mucolytic
properties in eucalyptus and rosemary essential oils?
A. Linalool
B. 1,8-Cineole (eucalyptol) [CORRECT]
C. Citral
D. Eugenol
Correct Answer: B
Rationale: Correct because 1,8-cineole is the dominant oxide in Eucalyptus globulus and
Rosmarinus officinalis ct. 1,8-cineole, responsible for expectorant, mucolytic, and
respiratory decongestant effects.
,2
Q4: Phenols such as thymol and carvacrol are characterized by which therapeutic property
and safety concern?
A. Strong antimicrobial activity but high dermal irritation potential [CORRECT]
B. Sedative effects with no safety concerns
C. Expectorant properties with phototoxicity risk
D. Anti-inflammatory action with neurotoxicity
Correct Answer: A
Rationale: Correct because phenols (thymol, carvacrol, eugenol) are potent antimicrobial
agents but are strong dermal irritants and mucous membrane irritants requiring low
dilution (typically <1%).
Q5: Monoterpenes such as limonene and α-pinene are known for which therapeutic action
and stability concern?
A. Strong sedative effects; highly stable
B. Antimicrobial, decongestant; prone to oxidation [CORRECT]
C. Hepatotoxic; requires refrigeration
D. Phototoxic; must be used in dark bottles only
Correct Answer: B
Rationale: Correct because monoterpenes (limonene, pinene, myrcene) are antimicrobial,
decongestant, and antiviral but oxidize readily when exposed to air, heat, and light,
increasing skin sensitization risk.
Q6: Which aldehyde-containing essential oil requires careful dilution due to significant skin
sensitization potential?
A. Lavender (Lavandula angustifolia)
B. Lemon myrtle (Backhousia citriodora) [CORRECT]
C. Tea tree (Melaleuca alternifolia)
D. Frankincense (Boswellia carterii)
Correct Answer: B
Rationale: Correct because lemon myrtle contains very high citral content (approximately
90-98%), making it a strong potential skin sensitizer; maximum dermal use is typically
0.7%.
Q7: Sesquiterpenes such as β-caryophyllene (found in black pepper and clove) are
distinguished by which molecular characteristic compared to monoterpenes?
A. They contain 15 carbon atoms and are less volatile [CORRECT]
,3
B. They contain 10 carbon atoms and are highly volatile
C. They are oxygen-containing compounds
D. They are water-soluble
Correct Answer: A
Rationale: Correct because sesquiterpenes (C15H24) have 15 carbon atoms versus
monoterpenes' 10 carbons (C10H16), making them heavier, less volatile, and often
contributing base notes to blends.
Q8: Which chemical family is associated with hepatotoxicity and neurotoxicity concerns,
particularly with prolonged use or high doses, and includes thujone and camphor?
A. Esters
B. Alcohols
C. Ketones [CORRECT]
D. Oxides
Correct Answer: C
Rationale: Correct because ketones (thujone in sage/wormwood, camphor in
rosemary/rosemary camphor/camphor wood) can be neurotoxic and hepatotoxic;
contraindicated in pregnancy, epilepsy, and children.
Q9: The phototoxic compound bergapten belongs to which chemical family?
A. Monoterpenes
B. Furocoumarins (coumarins) [CORRECT]
C. Phenols
D. Aldehydes
Correct Answer: B
Rationale: Correct because bergapten is a furocoumarin (psoralen) found in expressed
bergamot and other citrus oils; it reacts with UV light causing phototoxic burns and
blistering.
Q10: Linalool, geraniol, and citronellol belong to which chemical family known for antiviral,
antimicrobial, and generally skin-friendly properties?
A. Monoterpenols (alcohols) [CORRECT]
B. Monoterpenes
C. Phenols
D. Esters
, 4
Correct Answer: A
Rationale: Correct because monoterpenols (linalool in lavender, geraniol in rose/palmarosa,
citronellol in geranium) are antiviral, antimicrobial, and generally well-tolerated on skin
with low irritation potential.
Q11: Which oxide is primarily responsible for the strong expectorant action in Eucalyptus
globulus and can be neurotoxic if ingested in large amounts?
A. Linalool oxide
B. 1,8-Cineole (eucalyptol) [CORRECT]
C. Rose oxide
D. Bisabolol oxide
Correct Answer: B
Rationale: Correct because 1,8-cineole constitutes 70-85% of Eucalyptus globulus oil; it is a
powerful expectorant but can cause CNS depression and respiratory distress if ingested,
especially in children.
Q12: Which chemical constituent in oxidized citrus oils (particularly limonene) becomes a
significant skin sensitizer?
A. Citral
B. Limonene hydroperoxides [CORRECT]
C. Linalyl acetate
D. 1,8-Cineole
Correct Answer: B
Rationale: Correct because oxidation of limonene produces hydroperoxides that are potent
skin sensitizers; oxidized citrus oils should be discarded and storage must minimize
air/heat/light exposure.
Q13: The chemotype of Thymus vulgaris with the highest thymol content is:
A. Thymus vulgaris ct. linalool
B. Thymus vulgaris ct. geraniol
C. Thymus vulgaris ct. thymol [CORRECT]
D. Thymus vulgaris ct. carvacrol
Correct Answer: C
Rationale: Correct because Thymus vulgaris ct. thymol contains 40-60% thymol, making it
the most antimicrobial but also the most dermally irritating chemotype; ct. linalool is
gentler.
Aromatherapy Final Exam Prep 2026 — 100 Questions
with Complete Solutions
SECTION 1: ESSENTIAL OIL CHEMISTRY (15 Questions)
Q1: Which chemical family found in essential oils is known for its calming and antispasmodic
properties, is generally considered safe, and includes linalyl acetate (lavender) and geranyl
acetate (geranium)?
A. Monoterpenes
B. Esters [CORRECT]
C. Phenols
D. Ketones
Correct Answer: B
Rationale: Correct because esters (linalyl acetate, geranyl acetate, benzyl acetate) have
calming, balancing, antispasmodic, and antifungal properties with low dermal irritation risk.
Q2: A client with epilepsy requests an essential oil blend for stress relief. Which oil should be
avoided due to its neurotoxic ketone content (thujone)?
A. Lavender (Lavandula angustifolia)
B. Roman chamomile (Chamaemelum nobile)
C. Hyssop (Hyssopus officinalis) [CORRECT]
D. Frankincense (Boswellia carterii)
Correct Answer: C
Rationale: Correct because hyssop contains ketones including thujone, which is neurotoxic
and potentially convulsant; contraindicated in epilepsy.
Q3: Which chemical constituent is the primary contributor to the expectorant and mucolytic
properties in eucalyptus and rosemary essential oils?
A. Linalool
B. 1,8-Cineole (eucalyptol) [CORRECT]
C. Citral
D. Eugenol
Correct Answer: B
Rationale: Correct because 1,8-cineole is the dominant oxide in Eucalyptus globulus and
Rosmarinus officinalis ct. 1,8-cineole, responsible for expectorant, mucolytic, and
respiratory decongestant effects.
,2
Q4: Phenols such as thymol and carvacrol are characterized by which therapeutic property
and safety concern?
A. Strong antimicrobial activity but high dermal irritation potential [CORRECT]
B. Sedative effects with no safety concerns
C. Expectorant properties with phototoxicity risk
D. Anti-inflammatory action with neurotoxicity
Correct Answer: A
Rationale: Correct because phenols (thymol, carvacrol, eugenol) are potent antimicrobial
agents but are strong dermal irritants and mucous membrane irritants requiring low
dilution (typically <1%).
Q5: Monoterpenes such as limonene and α-pinene are known for which therapeutic action
and stability concern?
A. Strong sedative effects; highly stable
B. Antimicrobial, decongestant; prone to oxidation [CORRECT]
C. Hepatotoxic; requires refrigeration
D. Phototoxic; must be used in dark bottles only
Correct Answer: B
Rationale: Correct because monoterpenes (limonene, pinene, myrcene) are antimicrobial,
decongestant, and antiviral but oxidize readily when exposed to air, heat, and light,
increasing skin sensitization risk.
Q6: Which aldehyde-containing essential oil requires careful dilution due to significant skin
sensitization potential?
A. Lavender (Lavandula angustifolia)
B. Lemon myrtle (Backhousia citriodora) [CORRECT]
C. Tea tree (Melaleuca alternifolia)
D. Frankincense (Boswellia carterii)
Correct Answer: B
Rationale: Correct because lemon myrtle contains very high citral content (approximately
90-98%), making it a strong potential skin sensitizer; maximum dermal use is typically
0.7%.
Q7: Sesquiterpenes such as β-caryophyllene (found in black pepper and clove) are
distinguished by which molecular characteristic compared to monoterpenes?
A. They contain 15 carbon atoms and are less volatile [CORRECT]
,3
B. They contain 10 carbon atoms and are highly volatile
C. They are oxygen-containing compounds
D. They are water-soluble
Correct Answer: A
Rationale: Correct because sesquiterpenes (C15H24) have 15 carbon atoms versus
monoterpenes' 10 carbons (C10H16), making them heavier, less volatile, and often
contributing base notes to blends.
Q8: Which chemical family is associated with hepatotoxicity and neurotoxicity concerns,
particularly with prolonged use or high doses, and includes thujone and camphor?
A. Esters
B. Alcohols
C. Ketones [CORRECT]
D. Oxides
Correct Answer: C
Rationale: Correct because ketones (thujone in sage/wormwood, camphor in
rosemary/rosemary camphor/camphor wood) can be neurotoxic and hepatotoxic;
contraindicated in pregnancy, epilepsy, and children.
Q9: The phototoxic compound bergapten belongs to which chemical family?
A. Monoterpenes
B. Furocoumarins (coumarins) [CORRECT]
C. Phenols
D. Aldehydes
Correct Answer: B
Rationale: Correct because bergapten is a furocoumarin (psoralen) found in expressed
bergamot and other citrus oils; it reacts with UV light causing phototoxic burns and
blistering.
Q10: Linalool, geraniol, and citronellol belong to which chemical family known for antiviral,
antimicrobial, and generally skin-friendly properties?
A. Monoterpenols (alcohols) [CORRECT]
B. Monoterpenes
C. Phenols
D. Esters
, 4
Correct Answer: A
Rationale: Correct because monoterpenols (linalool in lavender, geraniol in rose/palmarosa,
citronellol in geranium) are antiviral, antimicrobial, and generally well-tolerated on skin
with low irritation potential.
Q11: Which oxide is primarily responsible for the strong expectorant action in Eucalyptus
globulus and can be neurotoxic if ingested in large amounts?
A. Linalool oxide
B. 1,8-Cineole (eucalyptol) [CORRECT]
C. Rose oxide
D. Bisabolol oxide
Correct Answer: B
Rationale: Correct because 1,8-cineole constitutes 70-85% of Eucalyptus globulus oil; it is a
powerful expectorant but can cause CNS depression and respiratory distress if ingested,
especially in children.
Q12: Which chemical constituent in oxidized citrus oils (particularly limonene) becomes a
significant skin sensitizer?
A. Citral
B. Limonene hydroperoxides [CORRECT]
C. Linalyl acetate
D. 1,8-Cineole
Correct Answer: B
Rationale: Correct because oxidation of limonene produces hydroperoxides that are potent
skin sensitizers; oxidized citrus oils should be discarded and storage must minimize
air/heat/light exposure.
Q13: The chemotype of Thymus vulgaris with the highest thymol content is:
A. Thymus vulgaris ct. linalool
B. Thymus vulgaris ct. geraniol
C. Thymus vulgaris ct. thymol [CORRECT]
D. Thymus vulgaris ct. carvacrol
Correct Answer: C
Rationale: Correct because Thymus vulgaris ct. thymol contains 40-60% thymol, making it
the most antimicrobial but also the most dermally irritating chemotype; ct. linalool is
gentler.
