2-Methylnaphthalene
Chemical Groups: Organic, Polyaromatic compounds, Polycyclic aromatic hydrocarbons
Also Known As: PAHs
CASRN: 91-57-6
Water Quality Guidelines for the Protection of Aquatic Life
Freshwater
Short Term Concentration (µg/L) No data
Long Term Concentration (µg/L) No data
Date No data
Marine
Short Term Concentration (µg/L) No data
Long Term Concentration (µg/L) No data
Date No data
Water Quality Guidelines for the Protection of Agriculture
Irrigation
Concentration (µg/L) No data
Date No data
Livestock
Concentration (µg/L) No data
Date No data
Sediment Quality Guidelines for the Protection of Aquatic Life
Freshwater
Concentration (µg/kg dry weight) ISQG 20.2
Provisional: adoption of marine ISQG
Concentration (µg/kg dry weight) PEL 201
Provisional: adoption of marine PEL
Date 1999
Marine
Concentration (µg/kg dry weight) ISQG 20.2
| Guideline |
% ≤ ISQG | ISQG < % < PEL | % ≥ PEL |
|---|---|---|---|
| Polycyclic aromatic hydrocarbons (PAHs) | |||
| Acenaphthene | 8 | 29 | 57 |
| Acenaphthylene | 7 | 14 | 51 |
| Anthracene | 9 | 20 | 75 |
| Benz(a)anthracene | 9 | 16 | 78 |
| Benzo(a)pyrene | 8 | 22 | 71 |
| Chrysene | 9 | 19 | 72 |
| Dibenz(a,h)anthracene | 16 | 12 | 65 |
| Fluoranthene | 10 | 20 | 80 |
| Fluorene | 12 | 20 | 70 |
| 2-Methylnaphthalene | 0 | 23 | 82 |
| Naphthalene | 3 | 19 | 71 |
| Phenanthrene | 8 | 23 | 78 |
| Pyrene | 7 | 19 | 83 |
Concentration (µg/kg dry weight) PEL 201
| Guideline | % ≤ ISQG | ISQG < % < PEL | % ≥ PEL |
|---|---|---|---|
| Polycyclic aromatic hydrocarbons (PAHs) | |||
| Acenaphthene | 8 | 29 | 57 |
| Acenaphthylene | 7 | 14 | 51 |
| Anthracene | 9 | 20 | 75 |
| Benz(a)anthracene | 9 | 16 | 78 |
| Benzo(a)pyrene | 8 | 22 | 71 |
| Chrysene | 9 | 19 | 72 |
| Dibenz(a,h)anthracene | 16 | 12 | 65 |
| Fluoranthene | 10 | 20 | 80 |
| Fluorene | 12 | 20 | 70 |
| 2-Methylnaphthalene | 0 | 23 | 82 |
| Naphthalene | 3 | 19 | 71 |
| Phenanthrene | 8 | 23 | 78 |
| Pyrene | 7 | 19 | 83 |
Date 1999
Soil Quality Guidelines for the Protection of Environmental and Human Health
Concentration (mg/kg dry weight) Agricultural No data
Concentration (mg/kg dry weight) Residential/ parkland No data
Concentration (mg/kg dry weight) Commercial No data
Concentration (mg/kg dry weight) Industrial No data
Date No data
Tissue Residue Quality Guidelines for the Protection of Widlife Consumer of Aquatic Biota
Concentration (µg/L) No data
Date No data
Groundwater Quality Guidelines for the Protection of Environmental and Human Health
(Coarse Soil) Concentration (mg/L) - Agricultural/Residential 0.15
| Land Use and Soil Texture | ||||
|---|---|---|---|---|
| Agricultural/Residential | Commercial/Industrial | |||
| Coarse | Fine | Coarse | Fine | |
| Guideline (provisional*) | 0.15 | 0.95 | 0.42 | 2.8ES |
| Human health guidelines | ||||
| Protection of indoor air quality (basement) #◊ | 0.15 | 0.95 | -- | -- |
| Protection of indoor air quality (slab on grade) #◊ | 0.20 | 1.0 | 0.42● | 2.8●ES |
| Protection of potable water | NA | NA | NA | NA |
| Environmental health guidelines | ||||
| Protection of freshwater life | NC | NC | NC | NC |
| Protection of marine life | NC | NC | NC | NC |
| Protection of livestock watering | NA | NA | NA | NA |
| Protection of irrigation water | NA | NA | NA | NA |
| Groundwater contact by soil-dependent organisms | NC | NC | NC | NC |
| Management considerations | ||||
| Water solubility (10%) † ¶¶ ‡‡ | 2.5 | 2.5 | 2.5 | 2.5 |
Notes: NC = not calculated (due to insufficient data); NA = not available (no CCME or Health Canada benchmarks are available); -- = the pathway is not considered for the selected land use.
Guidelines are based on soil and water quality guidelines/benchmarks current up to February 1, 2024.
* Provisional guideline. Protection of potable water and protection of aquatic life (freshwater and marine) are considered to be required exposure pathways; if any of these guidelines are missing, the final guideline is considered to be provisional. Missing pathways should be addressed on a site-specific basis.
# Tolerable concentration (TC) extrapolated from tolerable daily intake (TDI).
◊ Multiple lines of evidence are recommended to assess the vapour intrusion pathway; see Section 1.4 of CCME (2026).
● A high-level screening was not completed as no published air quality benchmark was available; therefore, no dose averaging was used (see Appendix A of CCME [2026]).
ES: Exceedance of 10% aqueous solubility; a separate phase may potentially be present. The presence of a free-phase liquid may invalidate guideline values for some pathways. Consult Section 1.3.3 of CCME (2026) for further information.
† This management limit is an alert to the potential presence of upstream sources of free-phase liquid. It is based on single substance contamination and may not be applicable to mixtures. Please consult Section 1.3.3 for further information. A value of 50% water solubility is used for a substance expected to form a separate phase less dense than water; a value of 10% water solubility is used for a substance expected to form a separate phase denser than water. Consult the jurisdictional authority for guidance if the management limit is exceeded.
¶¶ This substance is often found as part of a mixture; the management limit may not apply. Please consult Section 1.3.3 of CCME (2026) for further information.
‡‡ This substance has a density close to that of water and may potentially form a separate phase either less or more dense than water. The type of separate phase present should be determined.
(Coarse Soil) Concentration (mg/L) - Commercial/Industrial 0.42
| Land Use and Soil Texture | ||||
|---|---|---|---|---|
| Agricultural/Residential | Commercial/Industrial | |||
| Coarse | Fine | Coarse | Fine | |
| Guideline (provisional*) | 0.15 | 0.95 | 0.42 | 2.8ES |
| Human health guidelines | ||||
| Protection of indoor air quality (basement) #◊ | 0.15 | 0.95 | -- | -- |
| Protection of indoor air quality (slab on grade) #◊ | 0.20 | 1.0 | 0.42● | 2.8●ES |
| Protection of potable water | NA | NA | NA | NA |
| Environmental health guidelines | ||||
| Protection of freshwater life | NC | NC | NC | NC |
| Protection of marine life | NC | NC | NC | NC |
| Protection of livestock watering | NA | NA | NA | NA |
| Protection of irrigation water | NA | NA | NA | NA |
| Groundwater contact by soil-dependent organisms | NC | NC | NC | NC |
| Management considerations | ||||
| Water solubility (10%) † ¶¶ ‡‡ | 2.5 | 2.5 | 2.5 | 2.5 |
Notes: NC = not calculated (due to insufficient data); NA = not available (no CCME or Health Canada benchmarks are available); -- = the pathway is not considered for the selected land use.
Guidelines are based on soil and water quality guidelines/benchmarks current up to February 1, 2024.
* Provisional guideline. Protection of potable water and protection of aquatic life (freshwater and marine) are considered to be required exposure pathways; if any of these guidelines are missing, the final guideline is considered to be provisional. Missing pathways should be addressed on a site-specific basis.
# Tolerable concentration (TC) extrapolated from tolerable daily intake (TDI).
◊ Multiple lines of evidence are recommended to assess the vapour intrusion pathway; see Section 1.4 of CCME (2026).
● A high-level screening was not completed as no published air quality benchmark was available; therefore, no dose averaging was used (see Appendix A of CCME [2026]).
ES: Exceedance of 10% aqueous solubility; a separate phase may potentially be present. The presence of a free-phase liquid may invalidate guideline values for some pathways. Consult Section 1.3.3 of CCME (2026) for further information.
† This management limit is an alert to the potential presence of upstream sources of free-phase liquid. It is based on single substance contamination and may not be applicable to mixtures. Please consult Section 1.3.3 for further information. A value of 50% water solubility is used for a substance expected to form a separate phase less dense than water; a value of 10% water solubility is used for a substance expected to form a separate phase denser than water. Consult the jurisdictional authority for guidance if the management limit is exceeded.
¶¶ This substance is often found as part of a mixture; the management limit may not apply. Please consult Section 1.3.3 of CCME (2026) for further information.
‡‡ This substance has a density close to that of water and may potentially form a separate phase either less or more dense than water. The type of separate phase present should be determined.
(Fine Soil) Concentration (mg/L) - Agricultural/Residential 0.95
| Land Use and Soil Texture | ||||
|---|---|---|---|---|
| Agricultural/Residential | Commercial/Industrial | |||
| Coarse | Fine | Coarse | Fine | |
| Guideline (provisional*) | 0.15 | 0.95 | 0.42 | 2.8ES |
| Human health guidelines | ||||
| Protection of indoor air quality (basement) #◊ | 0.15 | 0.95 | -- | -- |
| Protection of indoor air quality (slab on grade) #◊ | 0.20 | 1.0 | 0.42● | 2.8●ES |
| Protection of potable water | NA | NA | NA | NA |
| Environmental health guidelines | ||||
| Protection of freshwater life | NC | NC | NC | NC |
| Protection of marine life | NC | NC | NC | NC |
| Protection of livestock watering | NA | NA | NA | NA |
| Protection of irrigation water | NA | NA | NA | NA |
| Groundwater contact by soil-dependent organisms | NC | NC | NC | NC |
| Management considerations | ||||
| Water solubility (10%) † ¶¶ ‡‡ | 2.5 | 2.5 | 2.5 | 2.5 |
Notes: NC = not calculated (due to insufficient data); NA = not available (no CCME or Health Canada benchmarks are available); -- = the pathway is not considered for the selected land use.
Guidelines are based on soil and water quality guidelines/benchmarks current up to February 1, 2024.
* Provisional guideline. Protection of potable water and protection of aquatic life (freshwater and marine) are considered to be required exposure pathways; if any of these guidelines are missing, the final guideline is considered to be provisional. Missing pathways should be addressed on a site-specific basis.
# Tolerable concentration (TC) extrapolated from tolerable daily intake (TDI).
◊ Multiple lines of evidence are recommended to assess the vapour intrusion pathway; see Section 1.4 of CCME (2026).
● A high-level screening was not completed as no published air quality benchmark was available; therefore, no dose averaging was used (see Appendix A of CCME [2026]).
ES: Exceedance of 10% aqueous solubility; a separate phase may potentially be present. The presence of a free-phase liquid may invalidate guideline values for some pathways. Consult Section 1.3.3 of CCME (2026) for further information.
† This management limit is an alert to the potential presence of upstream sources of free-phase liquid. It is based on single substance contamination and may not be applicable to mixtures. Please consult Section 1.3.3 for further information. A value of 50% water solubility is used for a substance expected to form a separate phase less dense than water; a value of 10% water solubility is used for a substance expected to form a separate phase denser than water. Consult the jurisdictional authority for guidance if the management limit is exceeded.
¶¶ This substance is often found as part of a mixture; the management limit may not apply. Please consult Section 1.3.3 of CCME (2026) for further information.
‡‡ This substance has a density close to that of water and may potentially form a separate phase either less or more dense than water. The type of separate phase present should be determined.
(Fine Soil) Concentration (mg/L) - Commercial/Industrial 2.8
| Land Use and Soil Texture | ||||
|---|---|---|---|---|
| Agricultural/Residential | Commercial/Industrial | |||
| Coarse | Fine | Coarse | Fine | |
| Guideline (provisional*) | 0.15 | 0.95 | 0.42 | 2.8ES |
| Human health guidelines | ||||
| Protection of indoor air quality (basement) #◊ | 0.15 | 0.95 | -- | -- |
| Protection of indoor air quality (slab on grade) #◊ | 0.20 | 1.0 | 0.42● | 2.8●ES |
| Protection of potable water | NA | NA | NA | NA |
| Environmental health guidelines | ||||
| Protection of freshwater life | NC | NC | NC | NC |
| Protection of marine life | NC | NC | NC | NC |
| Protection of livestock watering | NA | NA | NA | NA |
| Protection of irrigation water | NA | NA | NA | NA |
| Groundwater contact by soil-dependent organisms | NC | NC | NC | NC |
| Management considerations | ||||
| Water solubility (10%) † ¶¶ ‡‡ | 2.5 | 2.5 | 2.5 | 2.5 |
Notes: NC = not calculated (due to insufficient data); NA = not available (no CCME or Health Canada benchmarks are available); -- = the pathway is not considered for the selected land use.
Guidelines are based on soil and water quality guidelines/benchmarks current up to February 1, 2024.
* Provisional guideline. Protection of potable water and protection of aquatic life (freshwater and marine) are considered to be required exposure pathways; if any of these guidelines are missing, the final guideline is considered to be provisional. Missing pathways should be addressed on a site-specific basis.
# Tolerable concentration (TC) extrapolated from tolerable daily intake (TDI).
◊ Multiple lines of evidence are recommended to assess the vapour intrusion pathway; see Section 1.4 of CCME (2026).
● A high-level screening was not completed as no published air quality benchmark was available; therefore, no dose averaging was used (see Appendix A of CCME [2026]).
ES: Exceedance of 10% aqueous solubility; a separate phase may potentially be present. The presence of a free-phase liquid may invalidate guideline values for some pathways. Consult Section 1.3.3 of CCME (2026) for further information.
† This management limit is an alert to the potential presence of upstream sources of free-phase liquid. It is based on single substance contamination and may not be applicable to mixtures. Please consult Section 1.3.3 for further information. A value of 50% water solubility is used for a substance expected to form a separate phase less dense than water; a value of 10% water solubility is used for a substance expected to form a separate phase denser than water. Consult the jurisdictional authority for guidance if the management limit is exceeded.
¶¶ This substance is often found as part of a mixture; the management limit may not apply. Please consult Section 1.3.3 of CCME (2026) for further information.
‡‡ This substance has a density close to that of water and may potentially form a separate phase either less or more dense than water. The type of separate phase present should be determined.
Date 2026
Resources
- Polycyclic Aromatic Hydrocarbons (PAHs) - Canadian Sediment Quality Guidelines for the Protection of Aquatic Life (1999)
- Canadian Groundwater Quality Guidelines for the Protection of Environmental and Human Health (2026)
- Appendices C-F Canadian Groundwater Quality Guidelines for the Protection of Environmental and Human Health (2026)