Page 76 - Occupational Health & Safety, June 2017

OIL & GAS
or emergency situations, including uncon- trolled flammable vapor releases that can result in a fire or explosion hazard. Ensure the material is clearly understood by all af- fected personnel.
Minimum Safety Requirements of API RP 2219 - 2005
According to the API RP 2219 standard, “safe operation of vacuum truck tanks in petroleum service,” the following para- graphs are some that contain the minimum safety requirements that are essentials and associated with the BLSR accident.
1) Vacuum truck operators shall be aware that although BS&W may consist primarily of free water, sediment and/or emulsion, it may also entrain flammable or combustible hydrocarbons. Care should be exercised to understand the potential ignition and fire hazards associated with the material being handled. If condensate has been mixed with BS&W during the removal process, this can significantly in- crease the fire hazard. From a precaution- ary standpoint the mixture in the transport container should be treated as a flammable liquid absent positive identification to the contrary (section 4.1.4)
2) Unloading materials containing flammable components to open pads or pits can release vapors resulting in a fire, explosion or substance exposure hazard.
3) The method chosen for off-loading should include a review of the potential hazards of the material (flammability, cor- rosivity, and/ or toxicity) and ensure that where necessary, the procedures properly control vapors. Where flammable materials are involved, closed systems or appropri- ate ventilation may be necessary. Elimina- tion of potential ignition sources can be achieved by proper grounding, bonding, use of intrinsically safe equipment and shutting down equipment not in use (such as truck engines when gravity draining).
4) Smoking, or any other sources of ig- nition, shall not be permitted within at least 100 feet (depending on local procedures and atmospheric conditions) of the truck, the discharge of the vacuum pump, or any other vapor source. (section 5.12.5)
5) Sources of ignition include vacuum truck engine and exhaust heat, pump overheating, faulty or improper electri- cal devices, static electricity discharges, outside ignition sources such as smoking, motor vehicles, stationary engines, etc.
(section 5.1.1.1)
6) Vacuum truck owners shall assure
that vacuum truck operators are aware of the physical and chemical characteristics of flammable, combustible, toxic and cor- rosive materials in accordance with appli- cable regulations.
8) Vacuum truck owners shall prepare an emergency response plan conforming to OSHA requirements at 29 CFR 1910.38 (Employee Emergency Plans and Fire Pre- vention Plans), and shall train all operators in the use of that plan.
9) Operators can prevent diesel engine acceleration, or “runaway,” by locating the vacuum truck upwind of vapor sources and by extending the vacuum pump discharge away from the diesel engine air intake.
10) Vacuum truck operators shall be aware of the hazards involved in petroleum product and associated materials transfer operations. They shall be trained in safe product transfer practices and follow com- pany and facility safety procedures when loading and offloading vacuum trucks.
11) MSDSs for the products being transferred shall be available to vacuum truck operators. Safe air contaminant levels (PELs and STELs) shall be identified, and a qualified person shall assess the potential for exposure. (section 5.12.1)
12) Vacuum truck owners shall train vacuum truck operators in safe procedures for gauging and sampling flammable and combustible liquids and toxic materials in and around vacuum truck cargo tanks, source containers, and receipt containers.
13) The areas in which vacuum trucks are to operate must be free of hydrocarbon vapors in the flammable range, so testing shall be conducted when appropriate (test- ing shall be conducted before any operation is started, and if necessary, during opera- tions, when off-loading a waste container where pockets or layers of hydrocarbon, hydrogen sulfide, water and other hazard- ous materials may exist). Where required by facility procedures, permits shall be is- sued prior to the start of any vacuum truck operations. (section 5.2)
14) Potential hazards include spills, flammable atmosphere within and around the vacuum truck, cargo tank or source container, hose failures and discharges of flammable vapors to the atmosphere from the vacuum truck or the source or receiving container and worker exposures to toxic vapors, liquids or solids. (section 5.1.1.2)
15) Vacuum truck owners and opera- tors, as well as facility personnel, should be aware of the numerous potential hazards associated with vacuum truck operations in petroleum facilities. (section 5.1.1)
16) Whenever liquids or materials are transferred into or from a tank, vessel or container (other than a surface spill), a bonding cable shall be connected from the vacuum truck to the source or receiving container. (section 5.4.1.1)
17) Vacuum truck operators shall be aware that waste products from petroleum operations may contain trace amounts of flammable or combustible liquids and gases or other hazardous materials which may cause serious injury, illness or death, if not properly handled. In addition, vacuum truck operators shall be aware that when under vacuum, even trace amount of hy- drocarbons and hydrogen sulfide gas can be easily separated and create flammable and/or toxic atmospheres. (section 4.1.3)
18) Place an appropriate portable fire extinguisher (minimum 20 lb. BC), ready for use, within close proximity of the op- eration. (section D.4.1.7)
Conclusion
If we search industrial accidents to find the main causes, in most of the findings there would be at least one common important issue. Employers and workers need to pay special attention to minimum recommend- ed safety requirements of approved stan- dards, providing appropriate training, and preparing a safe working procedure.
Hamed Khoshniat is a senior safety officer, with nine years’ occupational safety experi- ence, in the Safety Department at Tabriz Oil Refining Company (www.tbz refinery.co.ir) in Iran. (hamedkhoshniat@gmail.com, phone number: 00984121148858). Part I of this article was published in the January 2017 issue of Occupational Health & Safety.
REFERENCES
1. CSB investigation report number 2003-06-I-TX September 2003, BLSR Operating , Ltd. Vapor cloud deflagration and fire accident
2. API RP 2219 – 2005 “safe operation of vacuum truck in petroleum service”
3. NFPA 69 – 2002, Standard on explosion prevention system
4. CCPS guideline for consequence analysis of chemical releases - 1999
72 Occupational Health & Safety | JUNE 2017
www.ohsonline.com