OSHA Safety and Health Regulations for Construction (29 CFR Part 1926) 1926.60: 1926.60 Methylenedianiline

Applies to construction work (as defined in 1910.12(b)) in which employees are exposed to MDA, meaning 4,4'-methylenedianiline (CAS 101-77-9) and its salts as vapor, liquid or solid. Covered work includes renovating or repairing MDA-containing structures, finishing surfaces with MDA products, spill cleanup and on-site handling or disposal. Out of scope: products that initial monitoring shows cannot exceed the action level (or objective data show cannot release MDA at all) under worst-case handling with no dermal contact possible; intact sealed containers (other than hazard communication and the emergency paragraph); materials below 0.1% MDA; and finished articles. Any such exemption must be backed by retained monitoring results or objective data. Limits: action level 5 ppb as an 8-hour TWA; PEL 10 ppb as an 8-hour TWA and a STEL of 100 ppb over any 15 minutes. On multi-employer sites, an employer applying MDA that must set up regulated areas tells the other employers about its MDA work and those areas. Each operation where an emergency is possible needs a written emergency plan that fixes escape routes before work begins, equips those correcting the emergency with the required PPE, covers alerting and evacuation, and includes the relevant 1910.38 and 1910.39 elements; affected employees not correcting the emergency are evacuated immediately. Monitoring uses full-shift breathing-zone samples taken per shift, job classification and work area (one shift suffices where equivalence is documented), with 15-minute samples for the STEL. Initial monitoring is required unless objective data or historical monitoring data show exposures stay below the action level. Repeat at least every 6 months from the action level up to the PELs, and at least every 3 months above the PELs (relaxable to 6 months after two results at least 7 days apart fall below the PELs); periodic monitoring may be skipped in a regulated area where every employee wears a supplied-air respirator. Monitoring for an employee may stop when the initial result, or two consecutive periodic results at least 7 days apart, fall below the action level, and restarts after any change in process, chemicals, controls, staff or practices. Accuracy must be within plus or minus 25 percent at 95 percent confidence. Results go to each affected employee within 5 working days, individually in writing or by posting, stating corrective action where a PEL is exceeded. The employer routinely inspects potentially exposed hands, faces and forearms and refers other reported skin exposure to medical personnel; where exposure is confirmed, the source is found, corrected and recorded. Regulated areas are set up wherever airborne levels exceed or may exceed a PEL or dermal exposure can occur: demarcated, restricted to authorized persons, PPE for all entrants, and no eating, drinking, smoking, gum, tobacco or cosmetics. Compliance relies on HEPA local exhaust, general ventilation, work practices or isolation and enclosure, supplemented by respirators; spray application always adds respirators; compressed air is barred unless paired with enclosed capture ventilation; employee rotation is not allowed. A written compliance program is reviewed at least every 12 months and furnished on request. Respirators follow a 1910.134 program, with HEPA filters, combination HEPA and organic vapor cartridges for liquid or heated MDA, defined escape options and a positive-pressure alternative. Protective clothing is free, bagged in sealed impermeable labeled containers, cleaned without releasing MDA and periodically checked for tears; launderers are informed. Decontamination and change areas (with an exception for small, brief jobs), showers where feasible above the PEL, clean lunch areas below the action level, and washing before eating are required. Hazard communication must cover cancer, liver effects and skin sensitization, with signs at regulated areas and their entrances reading DANGER, MDA, MAY CAUSE CANCER, CAUSES DAMAGE TO THE LIVER, RESPIRATORY PROTECTION AND PROTECTIVE CLOTHING MAY BE REQUIRED IN THIS AREA, AUTHORIZED PERSONNEL ONLY, and container labels reading DANGER, CONTAINS MDA, MAY CAUSE CANCER, CAUSES DAMAGE TO THE LIVER (older legends were allowed only before June 2016 for signs and June 2015 for labels); training is given at initial assignment and at least annually. Housekeeping includes a leak and spill detection program with regular visual inspections and no compressed-air cleaning. Medical surveillance applies to employees at or above the action level 30 or more days a year, with dermal exposure 15 or more days a year, exposed in an emergency, suspected of dermal exposure, or showing symptoms: initial and annual examinations with liver function tests, emergency and symptom examinations with retests two to three weeks later, a multiple-physician review, the written opinion given to the employee within 15 days, and medical removal with up to 6 months of removal benefits. Records: exemption data for as long as relied on, exposure records 30 years, medical records employment plus 30 years, training records 1 year beyond employment. Appendices A to D mirror the 1910.1050 appendices and add no obligations.