OSHA Crane Inspection Report and Analysis Oct 2001

NYC 9/11 Public Portal Document

LIBERTY MUTUAL.^

Industrial Hygiene Air Sample Results Summary for Week of 03/01/02 to03/08/02

Elevated exposures to asbestos are based on the results of analysis by phase contrast microscopy (PCM). This method counts all fibers detected that meet the critetia of “fiber”. Materials that are not asbestos may be included in the reported analysis. These samples have been submitted for further analysis by transmission electron microscopy (TEM) to make a definitive determination of the fibers detected by PCM analysis.

Although no elevated hydrogen sulfide results were found during the week. Liberty Mutual has recommended continuous monitoring for hydrogen sulfide during work in excavations. In past weeks, we have had a few quantifiable hydrogen sulfide results (one area sample was actually above the OEL). Also, there have been many anecdotal reports of hydrogen sulfide smells. Because of die insidious nature and serious effects of exposures to excessive levels of hydrogen sulfide , we feel that it is important to continuously monitor occupied spaces which are subject to build-up of “sewer gases”.

Some of the columos in the attached summary may require explanation:

Analyte Class - This column includes general category of the agents (substances) which were sampled.

# of Samples - This indicates how many individual samples were collected for the agent class listed.

# of Analysis - This is the number of individual analyses performed. If only one analysis is perfotmed on each sample, then the number of analytes will equal the number of sa es. However, most samples ate analyzed for more than one agent as follows:

Metals: Aluminum, antimony, arsenic, barium, beryllium, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, selenium, silver, thallium, tin, titanium, vanadium, and zinc. Metal samples ate sometimes also analyzed for total particulate.

Silica: Respirable dust, quartz, and cristobalite.

Acids: Hydtobromic add, hydrochloric add, hydrofluoric add, nitric add, phosphoric add and sulfuric add

Sulfides: Hydrogen sulfide and sulfur dioxide

OEL - Occupational Exposure Limit is the lower of the OSHA PEL or ACGIH TLV. PELs are established by an OSHA rule-making process and ate the legal occupational exposure standards. TLVs are voluntary guidelines for occupational exposure which ate established by the American Conference of Governmental Industrial Hygienists, a private professional otgaoization.

Highest % OEL - This is the percentage of the occupational exposure limit (OEL) that the highest result represents. This is the value in the “Highest Result” column divided by OEL and converted to a percentage.

Shift Adjusted OEL - The OEL reduced to compensate for the reduced recovery time and longer exposure time posed by a 7 day pet week , 12 hour shift work schedule.

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