LCS Laboratory Inc., routinely performs analysis on roofing tar for presence of coal tar. This screening test relies on tar solubility as a cost efficient way to estimate if the roofing material consists of coal tar or petroleum tar. The ultimate proof that the material contains coal tar, is by the analysis of Polynuclear Aromatic Hydrocarbons (PAH) in roofing material. PAH’s are aromatic compounds with two aromatic rings (naphthalene) or more. There are several hundred PAH’s including very complex branched molecules. The EPA has selected 16 PAH’s into a priority list based on their dominant presence in coal tar:
Naphthalene [91-20-3]
Acenaphthylene [208-96-8]
Acenaphthene [83-32-9]
Fluorene [86-73-7]
Phenanthrene [85-01-8]
Anthracene [120-12-7]
Fluoranthene [206-44-0]
Pyrene [129-00-0]
Benz[a]anthracene [56-55-3]
Chrysene [218-01-9]
Benzo[b]fluoranthene [205-99-2]
Benzo[k]fluoranthene [207-08-9]
Benzo[a]pyrene [50-32-8]
Dibenz[a,h]anthracene [215-58-7]
Benzo[ghi]perylene [191-24-2]
Indeno[1,2,3-cd]pyrene [193-39-5]
In this study 7 roofing tar samples that were positively identified as Coal Tar by the solubility test, were re-analysed for PAH’s using the NIOSH method 5515. This method was modified for the analysis of bulk tar. The samples were collected by 3 professional consultants operating in different parts of North America. Samples were taken as a part of the Health and Safety protocol before starting roof repair projects. The history of the samples is unknown, but we believe they had been exposed to sunlight and normal environmental weathering for 10 years or more.
Laboratory tests reveal that all samples contain a noticeable amount of PAH’s between 4% and 23% as total Polycyclic Hydrocarbons. The average concentration of individual PAH’s between 7 samples was as follows:
Average concentration of selected PAH’s in roofing Coal Tar
Naphthalene 0.2%
Acenaphthylene 0.1%
Acenaphthene 0.2%
Fluorene 0.2%
Phenanthrene 1.6%
Anthracene 0.5%
Fluoranthene 1.7%
Pyrene 1.2%
Benzo (a) anthracene 0.7%
Crysene 0.7%
Benzo (b) fluoranthene 1.1%
Benzo (k) fluoranthene 0.4%
Benzo (a) pyrene 1.3%
Indeno (1,2,3-CD) pyrene 1.1%
Dibenz (a,h) anthracene 0.1%
Benzo (g,h,i) perylene 1.0%
The study proves that the concentration of individual PAH’s in aged roofing tar are still extremely high. Remediation of coal tar requires extreme precautions, and implementation of vigorous safety programs. LCS Laboratory offers full laboratory support for your Coal Tar Investigation: analysis of roofing tar for coal tar presence; PAH’s in Coal Tar; PAH’s on wipe samples, PAH’s in air. To discuss your project or to order the test, please email us at your convenience.
