API RP 2023:2001 pdf download
API RP 2023:2001 pdf download.Guide for Safe Storage and Handling of Heated Petroleum-Derived Asphalt Products and Crude-Oil Residua.
Very brief high (under 1000 ppm) H2S exposures can cause severe respiratory difficulty, pulmonaiy edema unconsciousness. and death. Relatively low concentration levels (under 100 ppm) can cause irritation of the eyes, nose, and throat. Moderate levels can cause headache, dizziness, nausea, and vomiting, as well as cough and breathing difficulty. The severity of effects depends on the concentration and duration of exposure. Personnel working around hydrogen sulfide should be aware that these symptoms can warn of potentially more dangerous exposure and thgger an investigation using appropriate protective gear. The original NIOSH IDLH level of 300 PPM was lowered to 100 PPM in the mid-i 990s. The ACGIH TLV in 2000 was 10 ppm with an STEL/C of 15 ppm. ACGIH have published a ‘Notice of Intended Change” to lower their TLV to 5 ppm.
CAUTION: Although H2S has a strong odor (often compared to rotten eggs), smell cannot be relied on to warn of danger. Brief exposure to high concentrations of H2S can immediately paralyze the sense of smell and more extended exposure to lower concentrations has a similar olfactory nerve paralysis desensitizing effect. The strong odor of heated petroleum-derived asphalt products and crude oil residua can “mask” the odor of H2S when present in these products and residua.
Personnel with the potential for exposure to hydrogen sulfide should be trained about H2S hazards and where exposure to hydrogen sulfide could be possible. Respiratory protection should be required where appropriate. Candidate activities include tank gauging, maintenance and barge, tank truck or rail car filling. (e.g. open transfer).
The Agency for Toxic Substances and Disease Registry includes information on hydrogen sulfide in their publication “ATSDR Medical Management Guidelines for Acute Chemical Exposures: Chemical Protocols” posted on their web site at: www.atsdr.cdc.gov/mmgl 5.html.
4.3.2 INERT ATMOSPHERE HEALTH HAZARDS
Inert (oxygen deficient) atmospheres such as nitrogen or flue gas are sometimes used to blanket the liquid in a tank to reduce the probability of a fire (although an inert atmosphere encourages the build-up of pyrophoric material in tanks). The lack of oxygen in inert atmospheres represents an acute hazard to personnel under certain exposure conditions. In the unlikely case where a person manages to enter and stay in a totally enclosed space without any oxygen the person may collapse and death can occur. If the employee is briefly exposed or surrounded by a transient oxygen deficient atmosphere (such as while gauging or venting an inert-blanketed tank) then dizziness might result. if this atmosphere is from the tank vapor space then there can be significant concentrations of hydrocarbon vapor which may compound the effects. These effects should pass when the person again is breathing normal air; however, during the period affected, there is risk of inadvertent action such as failing or contacting hot surfaces. See 6.2 & 6.3 for more information on pyrophorics.
4.3.3 FUMES AND VAPORS
inhalation exposure to vapors and fumes from heated asphalt can have effects occurring from exposure over a short time, such as irritation of the eyes or respiratory system. “Cutback ’ asphalt or residual fuel blended with lighter distillate hydrocarbons may release vapors from the distillate hydrocarbon component which can cause irritation, light-headedness or headaches. All of these short-term exposure effects are considered reversible when removed from exposure.
Threshold Limit Values and Permissible Exposure Limits are intended to address longer term repeated exposure. The 2000 edition of the ACGIH publication TLVs® and BEIs®
—Threshold Limit Values Jbr Chemical Substances and Physical Agents and Biological Fposure Indices—lists “Asphalt (Petroleum; Bitumen) Fume” with a TLV of 0.5 mg/rn3. This is a tenfold reduction from the previous TLV of 5.0 mg/rn3. ACGIH indicate that this new limit is based on “irritation” (primarily of mucous membrane in eyes and respiratory tract).
There is no OSHA Permissible Exposure Limit (PEL) for asphalt fume. OSHA has stated specifically that limits for coal tar pitch volatiles (FR 29 1910.1002) do not apply to asphalt from any source.
