Safety: Confined Space Entry for Tank Lining
A 10,000-gallon steel tank is being lined with a solvent-based epoxy. The tank is 10 feet in diameter and 20 feet high with a 20-inch manhole. The contractor plans to have two workers inside the tank applying the coating using airless spray. The inspector must verify safety compliance. The contractor has provided a confined space entry permit, but the permit does not include atmospheric monitoring results. The workers are wearing half-face respirators with organic vapor cartridges. The tank has been ventilated with a blower for 30 minutes before entry. The coating contains xylene and MEK. The inspector notices that the workers are not using supplied air and that the ventilation is not continuous. The contractor argues that the tank is small and the job will be quick.
1. Identify the safety hazards and violations in this scenario. What are the applicable standards and requirements?
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The scenario presents several safety hazards and potential violations: 1) Confined space entry without atmospheric monitoring: The permit lacks monitoring results, which is a violation of OSHA 29 CFR 1910.146 (or 1926.1200 for construction). The atmosphere must be tested for oxygen, flammables, and toxics before entry and continuously during entry. 2) Inadequate respiratory protection: Half-face respirators with organic vapor cartridges may not provide adequate protection for solvent vapors in a confined space, especially during spray application. Supplied air respirators (SAR) or self-contained breathing apparatus (SCBA) are typically required for spray painting in confined spaces due to the potential for high vapor concentrations and oxygen deficiency. 3) Inadequate ventilation: The blower was used for only 30 minutes and is not continuous. Continuous ventilation is required to maintain safe atmospheric conditions. The ventilation should be explosion-proof and provide sufficient air changes. 4) Fire and explosion hazard: Solvents like xylene and MEK are flammable. The spray application in a confined space can create an explosive atmosphere. All electrical equipment must be explosion-proof, and bonding and grounding are required. 5) Inadequate rescue plan: The permit should include a rescue plan and retrieval system. 6) Workers not wearing proper PPE: They may need protective clothing, eye protection, and chemical-resistant gloves. 7) The contractor's argument that the job is small and quick is irrelevant; safety standards apply regardless of duration. Applicable standards: OSHA 29 CFR 1910.146 (Permit-required confined spaces) and 29 CFR 1910.134 (Respiratory protection), 29 CFR 1910.107 (Spray finishing operations). For construction, 29 CFR 1926.1200 series.
2. What actions should the inspector take to ensure safety before work proceeds?
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The inspector should immediately stop work and require the contractor to correct the safety deficiencies: 1) Conduct atmospheric testing for oxygen (19.5-23.5%), flammables (<10% LEL), and toxics (e.g., xylene and MEK below exposure limits) before entry and continuously during work. Use a calibrated direct-reading instrument. 2) Provide continuous mechanical ventilation with explosion-proof equipment. Ensure sufficient air changes to keep vapor concentrations below 10% LEL and within exposure limits. 3) Upgrade respiratory protection to supplied air respirators (Type C) or SCBA for all workers inside the tank during spray application. Half-face respirators are not adequate for confined space spray painting. 4) Ensure all electrical equipment, including lights and spray equipment, is explosion-proof and properly grounded. 5) Develop and implement a rescue plan with a retrieval system and trained attendants outside the tank. 6) Verify that workers are trained in confined space entry and respiratory protection. 7) Ensure the permit is fully completed with all monitoring results and signed. 8) Provide appropriate PPE: chemical-resistant coveralls, gloves, and eye protection. 9) The inspector should document all findings and not allow entry until all requirements are met. The inspector may need to consult with a safety professional.