Releases, leaks, spills, and exposures at work
We review exposure to a chemical, gas, vapor, dust, or fume at work, whether in a single event such as a release from a process unit, a leaking valve, a ruptured line, a spill during transfer, or a tank or confined-space atmosphere, or over time through repeated exposure in the same job. It applies in any setting: a refinery or chemical plant, a wellsite, a terminal, a warehouse, a laboratory, a construction site, or a truck cab. We investigate the companies and the operation in each setting alongside the evidence establishing the exposure.
Four facts decide the review. What was the substance? How much of it was present where the person was? For how long, and by what route? What did the employer and the facility know about it and do about it before and after? Each has its own records, and the sections below describe them. If the substance ignited, the event is reviewed for its mechanism as an explosion. Diseases that develop years after exposure to materials such as asbestos raise different questions and are not described on this page.
Identifying the chemical: labels, safety data sheets, and inventories
The federal hazard communication rule requires the manufacturer or importer of a hazardous chemical to label each shipped container with a product identifier, a signal word, hazard statements, pictograms, and precautionary statements. It also requires a safety data sheet in sixteen standard sections, from identification and composition through hazards, first-aid measures, exposure controls and protective equipment, toxicological information, and, in the last section, the date the sheet was prepared or last revised.
The employer must have a written hazard communication program, keep a safety data sheet for every hazardous chemical in the workplace, make the sheets readily accessible to workers during each shift, and train workers about the chemicals in their area when they are first assigned and whenever a new hazard is introduced.
The rule was recently revised to align with an updated international system. During the transition both the previous and the updated formats are in circulation, so the version and date of the sheet in the binder are themselves facts to establish.
In Texas, a separate state hazard communication statute applies to public employers, which federal OSHA does not cover.
Facilities that hold hazardous chemicals above threshold amounts also file annual chemical inventories with the Texas Commission on Environmental Quality, which shares them with local emergency planning committees and fire departments. Together with a process facility’s own records, the labels, sheets, and inventories identify the substance. The firm does not interpret a safety data sheet for a reader; it uses the sheet to identify what to request and what to ask the treating physician.
Concentration, duration, route, and the protective equipment in use
How much of a substance reached the person, for how long, and by what route are established from monitoring rather than from memory. Fixed detectors and area monitors record concentrations and alarms at set points; personal monitors and sampling badges worn by the worker record what reached the breathing zone; industrial hygiene sampling by the employer or its consultant records shift averages and short-term peaks; and calibration and bump-test records show whether any of those instruments were working. The route, whether inhalation, skin or eye contact, or ingestion, is established from the work being done, the equipment in use, and the medical findings.
Where respirators are necessary to protect health, the employer must have a written respiratory protection program with worksite-specific procedures, must provide respirators, training, and medical evaluations at no cost, must medically evaluate each worker before fit testing or use, and must fit test the respirator to the worker. The program, the medical clearances, the fit-test records, the cartridge-change schedules, and the records of other protective equipment issued and inspected show what stood between the worker and the substance. A facility’s job safety analyses, permits to work, and confined-space entry permits, with their atmospheric test results, record what the companies expected the atmosphere to be.
Exposure limits are reference points, not the answer
OSHA’s permissible exposure limits take three forms: an eight-hour time-weighted average that may not be exceeded over a shift, a ceiling that may not be exceeded at any time, and, for some substances, a short peak above the ceiling permitted once for a limited period. Hydrogen sulfide, for example, has a ceiling and a limited peak in OSHA’s tables. Benzene and formaldehyde have their own OSHA standards, with exposure limits, action levels that trigger monitoring, medical surveillance programs, and record-retention requirements measured in decades. Where a limit is exceeded, the rules require engineering or administrative controls first and respirators where those are not feasible.
OSHA itself states that many of its permissible exposure limits are outdated and inadequate for protecting worker health, most having been adopted shortly after 1970 and not updated since, and it directs employers to the other limits a safety data sheet must list, including the recommended limits published by the National Institute for Occupational Safety and Health and the threshold limit values published by a professional association. A reading below a limit is therefore a regulatory fact, not a medical or legal conclusion, and a reading depends on where and when the sample was taken and what it measured. The firm reviews the underlying monitoring data and sampling method rather than the company’s summary, and it places them against the medical record.
Your right to exposure and medical records
A federal rule gives every employee, and any representative the employee designates in writing, a right of access to the exposure records and medical records the employer keeps concerning that employee, including monitoring results, sampling data, safety data sheets, and medical surveillance records. Employers must preserve exposure records for at least thirty years and medical records for the duration of employment plus thirty years, and when a request is made they must provide access within fifteen working days or explain the reason for the delay and the earliest date the record will be available. Unlike a worksite, which changes within days, an exposure record is meant to outlast the job. The firm makes the request in the form the rule requires.
Releases that reach the community: notifications and public records
A release does not stop at the fence, and neither do the records. Facilities must immediately report accidental releases of listed extremely hazardous substances above reportable quantities to the state emergency response commission and the local emergency planning committee, followed by a written report, and those bodies must make the reports available to the public. Releases of listed hazardous substances above reportable quantities must also be reported to the National Response Center, whose public data are initial reports that have not been validated or investigated. In Texas, a facility must notify the Texas Commission on Environmental Quality of a reportable emissions event and file a final report afterward, and the agency’s emissions-event database is searchable by the public; those reports are part of a refinery accident review, and the U.S. Chemical Safety and Hazard Investigation Board’s role is described with explosions. Annual release data reported by industrial facilities are published in the federal Toxics Release Inventory.
In Harris County, shelter-in-place notices for an airborne chemical hazard are issued through the county’s emergency alert systems and its office of emergency management, and the county’s pollution control department conducts air monitoring and receives complaints. For an exposure review the useful records are the air-monitoring data taken during the response and the notice times, which fix when the hazard was recognized and who was told to stay indoors; such notices establish the timeline and who was affected, not who was responsible. This page describes workplace exposures and does not address claims by residents or nearby businesses.
The medical record, read alongside the exposure record
The exposure record and the medical record are read together. The first-aid or plant-clinic record, the emergency department record, the follow-up visits, any toxicology the treating physicians ordered, any poison-control contact, and the physician’s notes about what the patient reported being exposed to form the chronology that connects the event to the diagnosis. Where a substance-specific OSHA standard applies, the employer’s medical surveillance records show the worker’s baseline before the exposure. The firm gives no medical advice. It asks the injured person to see a physician promptly, to tell the physician about the exposure and not only the symptoms, and to keep the discharge papers, because the physician’s contemporaneous note of the exposure is part of the record no later document can replace.
Hydrogen sulfide, benzene, and Houston’s process industries
Houston’s refineries, chemical plants, terminals, wellsites, and the trucking and rail operations that serve them handle the substances that OSHA regulates most specifically. Hydrogen sulfide is a colorless gas known for its rotten-egg odor at low concentrations; it is flammable, it is heavier than air and collects in low-lying and enclosed spaces, and OSHA lists oil and gas refining among the industries where it is encountered. Benzene is a component of products derived from petroleum and is found in gasoline and other fuels, and it is governed by its own OSHA standard. Ammonia, chlorine, sulfur dioxide, acids, caustics, and solvents are handled in the same corridor under their own rules. The wellsite health hazards OSHA names, including hydrogen sulfide and respirable silica, and the wellsite gas-monitoring records are catalogued with oilfield accidents; those records are read against exposure limits and medical findings in any setting.
Ignition, burns, the facility, and death: the neighboring pages
- If the substance ignited, the event is reviewed for its mechanism as an explosion.
- A chemical burn is reviewed for its medical course as a burn injury.
- The facility’s process, permit, contractor, and control-system records are those of a refinery accident, and the wellsite’s companies and records those of an oilfield accident.
- The coverage status of each company, the non-subscriber track, and the weight of an OSHA inspection are common to every workplace injury, and pursuing a company other than the employer is a third-party workplace claim.
- A death from an exposure brings in the family and estate questions of a wrongful death claim.
Bringing a chemical exposure to the firm
An exposure review starts with the substance as the injured person knows it, from a label, a product name, or the unit involved; the place, date, and time; the employer and the facility; the names of others exposed; any monitor readings, alarms, or notices the person saw or received; and the medical care so far, with the discharge papers. Photographs of labels and of the safety data sheet binder, and the name of the physician who first documented the exposure, are worth more than a recollection of the smell. Leatherwood & Schindler reviews exposure matters from its one Houston office, and a consultation begins with the four facts described above and the records that establish them.