Toxicology – Caustics—Basic (Alkaline Corrosives)

Core concept

Strong alkalis cause corrosive injury by saponifying membrane lipids and producing liquefactive necrosis, allowing deep tissue penetration.

The classic injury sequence is:

Strong alkali contact → fat saponification + protein dissolution → liquefactive necrosis → deep esophageal injury → perforation or later stricture

Compared with acids, alkalis classically cause more prominent esophageal injury because many alkaline products are viscous and remain in contact with the esophageal mucosa.

However:

The acid-versus-alkali distinction should not be used to predict injury severity in an individual patient.

Both can cause devastating:

• Esophageal necrosis
• Gastric injury
• Perforation
• Airway edema
• Death

Modern management centers on:

Early airway assessment + resuscitation + injury staging with endoscopy and/or contrast-enhanced CT

There is no specific antidote.

Important Alkaline Caustics

Common clinically important alkalis include:

• Sodium hydroxide — lye/caustic soda
• Potassium hydroxide — caustic potash
• Calcium hydroxide
• Calcium oxide / quicklime
• Ammonia/ammonium hydroxide
• Sodium metasilicate
• Sodium carbonate
• Potassium carbonate
• Trisodium phosphate
• Portland cement
• Some drain cleaners
• Oven cleaners
• Industrial degreasers
• Hair relaxers

Important modernization

The older list includes several compounds that are not equally corrosive simply because they are alkaline or are found in cleaning products.

Corrosive potential depends on:

Concentration + titratable alkalinity + physical form + amount + duration of contact

rather than the chemical name or pH alone.

Household Sources

Potential sources include:

• Drain openers
• Oven cleaners
• Industrial cleaners
• Dishwasher products
• Hair-relaxing products
• Cement/lime products
• Degreasers
• Metal cleaners

Some household detergents are only irritants, whereas concentrated drain cleaners containing sodium or potassium hydroxide can cause profound necrosis after very small ingestions.

Toxic Dose

There is no reliable universal toxic dose.

Only a few milliliters of concentrated sodium or potassium hydroxide may cause major injury.

Risk depends on:

• Concentration
• pH
• Titratable alkalinity
• Volume
• Viscosity
• Solid vs liquid formulation
• Contact duration

pH

A product with:

pH >11–11.5

raises concern for significant alkaline corrosive potential.

But:

pH alone does not determine injury severity.

A high-pH product with low titratable alkalinity may behave differently from concentrated lye with a similar measured pH.

Pathophysiology

Liquefactive Necrosis

Strong bases cause:

Hydroxide ion → lipid saponification + protein dissolution → cellular destruction

This produces:

Liquefaction necrosis

Unlike coagulative necrosis, liquefactive injury does not form an effective protective eschar.

Therefore alkali can continue penetrating:

Mucosa → submucosa → muscularis → adventitia

leading to:

• Deep ulceration
• Vascular thrombosis
• Transmural necrosis
• Perforation

Esophageal Predominance

Alkalis traditionally produce greater esophageal injury because:

• Many are viscous
• They adhere to mucosa
• They may remain in the esophagus longer

This contrasts with strong acids, which often produce substantial gastric injury.

However:

Severe alkaline ingestion can injure the stomach and duodenum as well.

Tissue Evolution

First hours

• Edema
• Erythema
• Necrosis
• Vascular thrombosis

First several days

• Mucosal sloughing
• Inflammation
• Bacterial infiltration
• Progressive tissue weakness

Healing phase

• Granulation
• Collagen deposition
• Fibrosis

leading to:

Esophageal stricture ± gastric outlet obstruction

The injured GI wall can become particularly friable during the healing period, making unnecessary instrumentation hazardous.

Clinical Features

Oropharyngeal

Possible findings include:

• Burning pain
• Lip/tongue burns
• Oral ulceration
• Drooling
• Dysphagia
• Odynophagia
• Hoarseness
• Stridor

Critical pearl

The mouth may look completely normal despite severe esophageal injury.

Absence of oral burns does not safely exclude clinically important GI injury. (NCBI⁠)

Airway

Caustic exposure can cause:

• Supraglottic edema
• Laryngeal edema
• Laryngospasm
• Stridor
• Airway obstruction

Aspiration or inhalation can also cause:

• Bronchospasm
• Chemical pneumonitis
• Pulmonary edema
• ARDS

Warning signs include:

• Progressive hoarseness
• Stridor
• Drooling/inability to handle secretions
• Hypoxemia
• Increasing respiratory effort

Therefore:

A threatened airway should be secured early.

Do not wait until progressive edema makes intubation extremely difficult.

Gastrointestinal

Symptoms may include:

• Dysphagia
• Odynophagia
• Retrosternal pain
• Epigastric pain
• Nausea
• Vomiting
• Hematemesis
• Abdominal tenderness

Severe poisoning can cause:

• Gastrointestinal hemorrhage
• Mediastinitis
• Peritonitis
• Esophageal/gastric perforation
• Shock

Perforation

Suspect transmural injury/perforation with:

• Severe or worsening chest pain
• Severe abdominal pain
• Guarding/rebound
• Subcutaneous emphysema
• Pneumomediastinum
• Pneumoperitoneum
• Fever/sepsis
• Hemodynamic instability
• Rising lactate/metabolic acidosis

This is a:

Surgical emergency

A normal plain radiograph does not reliably exclude serious transmural injury.

Cardiovascular

Severe caustic injury may produce:

• Tachycardia
• Hypotension
• Hemorrhagic shock
• Inflammatory/distributive shock
• Cardiovascular collapse

Shock can result from:

• GI hemorrhage
• Massive third-spacing
• Necrotic tissue injury
• Perforation
• Sepsis

Renal / Metabolic

Possible complications include:

• Metabolic acidosis
• Lactic acidosis
• Acute kidney injury
• Electrolyte abnormalities

These usually indicate:

• Severe tissue necrosis
• Shock
• Hemorrhage

rather than a characteristic direct systemic effect of sodium hydroxide itself.

Skin Exposure

Alkaline solutions may produce surprisingly deep burns because liquefactive necrosis continues while the chemical remains in contact.

Possible manifestations:

• Pain
• Slippery/soapy sensation
• Erythema
• Blistering
• Ulceration
• Deep/full-thickness burn

Portland cement

Wet cement is particularly important because prolonged skin contact may produce:

Delayed deep alkaline burns

sometimes with little early pain.

Calcium Oxide / Dry Lime

Dry quicklime reacts with water:

CaO + H₂O → Ca(OH)₂ + heat

Therefore:

Brush off dry particulate material before beginning copious water irrigation.

Once dry material is removed, irrigate thoroughly.

This principle also applies to contaminated clothing containing large amounts of dry caustic powder.

Ocular Exposure

Alkali eye injuries are especially dangerous because bases can penetrate ocular tissues rapidly.

Possible complications include:

• Conjunctival burns
• Corneal epithelial loss
• Stromal injury
• Limbal ischemia
• Corneal opacification
• Cataract
• Glaucoma
• Globe perforation
• Permanent blindness

Alkali ocular exposure is an emergency requiring immediate irrigation.

Inhalational Exposure

Aerosols, dusts, or ammonia-containing alkaline products may cause:

• Upper-airway irritation
• Cough
• Wheezing
• Bronchospasm
• Laryngospasm
• Pulmonary edema
• Chemical pneumonitis
• ARDS

Patients with significant inhalational exposure require careful observation because respiratory injury may evolve after the initial contact.

Diagnosis

Diagnosis depends on:

Exposure history + physical examination + assessment of injury depth

Do not determine severity from:

• Mouth appearance alone
• Product pH alone
• Reported volume alone

Whenever possible obtain:

• Product name
• Ingredient list
• Concentration
• Amount
• Time of exposure
• Intentional vs accidental exposure

Differential Diagnosis

Consider:

• Acid ingestion
• Button battery ingestion
• Hydrogen peroxide
• Phenol
• Formaldehyde
• Zinc chloride
• Mercuric chloride
• Iron preparations
• Severe GI irritants

Important

Button batteries are a distinct emergency.

Their injury results largely from:

Electrical current → local hydroxide generation → liquefactive necrosis

and they require their own urgent removal algorithm.

Laboratory Testing

Minor exposure

No routine testing may be necessary after a clearly trivial accidental exposure in a completely asymptomatic patient.

Symptomatic/significant exposure

Consider:

• CBC
• Electrolytes
• Bicarbonate
• BUN
• Creatinine
• Glucose

For severe toxicity:

• Blood gas
• Lactate
• PT/INR
• aPTT
• Fibrinogen
• Type and crossmatch
• Liver enzymes

Abnormal:

• Acidosis
• Leukocytosis
• Renal dysfunction
• Lactate

may help identify patients with substantial tissue injury, but no laboratory value replaces direct injury assessment.

Plain Imaging

Chest and abdominal radiographs may identify:

• Pneumomediastinum
• Pleural abnormalities
• Pneumoperitoneum

but:

Normal plain films do not exclude transmural necrosis or perforation.

Contrast-Enhanced CT

Modern management increasingly incorporates:

Contrast-enhanced CT of the neck/chest/abdomen

in significant adult caustic ingestions.

CT can evaluate:

• Esophageal-wall injury
• Gastric injury
• Periesophageal inflammation
• Mediastinal injury
• Intramural gas
• Free air
• Adjacent-organ involvement
• Transmural necrosis

The most important CT feature suggesting irreversible transmural injury is:

Absent post-contrast wall enhancement

WSES guidance considers this an indication for emergency surgical management when convincing transmural necrosis is present. (PubMed Central (PMC)⁠)

CT vs Endoscopy

This is an evolving area.

WSES supports a CT-based approach in adults because CT may be superior for detecting transmural necrosis. (PubMed Central (PMC)⁠)

However, a 2025 comprehensive review concluded that evidence is still insufficient to universally replace EGD; endoscopy remains the predominant first-line assessment in many centers, while CT is increasingly used as a complementary or alternative tool in high-risk adults. (PubMed Central (PMC)⁠)

Therefore:

EGD and CT should be viewed as complementary, not automatically competing, tests.

A useful conceptual distinction:

EGD → mucosal/luminal injury

CT → depth of injury/transmural necrosis + extraluminal structures

Upper Gastrointestinal Endoscopy

EGD remains important after:

• Significant intentional ingestion
• Large/concentrated ingestion
• Drooling
• Dysphagia
• Odynophagia
• Persistent vomiting
• Chest/abdominal pain
• Significant oral/pharyngeal injury
• Other concerning clinical features

When indicated, it is commonly performed:

Within approximately 12–24 hours

after ingestion.

The exact approach depends on local GI, surgical, radiology, and toxicology expertise. (PubMed Central (PMC)⁠)

When EGD May Not Be Necessary

Routine endoscopy is not required after every childhood “taste.”

A patient with a clearly:

• Small accidental exposure
• Low-concentration household product
• Normal examination
• No symptoms
• Normal swallowing

may be managed without invasive evaluation after appropriate risk assessment.

Intentional adult ingestion is substantially different and usually deserves formal assessment.

Zargar Endoscopic Classification

Grade 0

Normal mucosa

Grade I

• Edema
• Hyperemia

Generally excellent prognosis.

Grade IIa

• Friability
• Hemorrhage
• Erosions
• Blisters
• Superficial ulcers
• Exudate

Usually relatively low stricture risk.

Grade IIb

Grade IIa features plus:

Deep or circumferential ulceration

This carries substantial risk of later stricture.

Grade IIIa

Focal necrosis

Grade IIIb

Extensive necrosis

Grade III injury carries major risk of:

• Perforation
• Hemorrhage
• Systemic complications
• Death

Endoscopy cannot always accurately determine whether necrosis extends through the entire wall, which is why CT has become increasingly important. (PubMed Central (PMC)⁠)

Treatment

1. Airway First

Immediately assess:

• Voice
• Secretions
• Stridor
• Respiratory effort
• Oropharyngeal edema
• Oxygenation

If airway edema is progressing:

Intubate early

Ideally use:

• Experienced airway operator
• Video laryngoscopy or fiberoptic techniques as appropriate
• Surgical airway backup

Repeated traumatic attempts can worsen edema and bleeding.

2. Breathing

For inhalational injury:

• Remove from exposure
• Oxygen if hypoxemic
• Inhaled β₂ agonist for bronchospasm

Severe chemical lung injury is managed with:

• Appropriate ventilatory support
• Lung-protective ventilation if ARDS develops

3. Circulation

Establish IV access.

Treat significant volume loss or shock with:

• Isotonic crystalloid when appropriate
• Blood products for significant hemorrhage

If hypotension persists despite adequate resuscitation:

Norepinephrine is generally an appropriate first vasopressor.

4. Do NOT Induce Vomiting

Never induce emesis.

Vomiting causes a second caustic exposure to the esophagus and increases aspiration risk.

Ipecac has no role.

5. Do NOT Neutralize Alkali With Acid

The historical idea of giving:

• Vinegar
• Lemon juice
• Other acids

is dangerous.

Neutralization can cause:

Acid + base reaction → heat generation → additional thermal injury

Therefore:

Do not attempt chemical neutralization.

6. Routine Milk/Water Dilution Is No Longer Recommended

Older texts advise approximately 4 oz of milk or water.

Modern guidance does not recommend routine dilution.

Potential concerns include:

• Vomiting
• Aspiration
• Gastric distention
• No proven clinical outcome benefit

Any theoretical effect would require administration almost immediately after exposure, and supporting human data are poor. (NCBI⁠)

Therefore:

Do not routinely force oral water or milk after caustic ingestion.

7. No Gastric Lavage

Gastric lavage is contraindicated/not routinely appropriate.

It can:

• Re-expose the esophagus
• Cause perforation
• Cause bleeding
• Increase aspiration

8. Activated Charcoal

Activated charcoal has no routine role in isolated alkali ingestion.

Most caustic alkalis are poorly adsorbed, and charcoal may:

• Induce vomiting
• Increase aspiration risk
• Obscure endoscopic visualization

Use charcoal only when there is a separate clinically important charcoal-adsorbable coingestant and the airway is safe.

9. Avoid Blind NG/OG Tube Placement

Blind instrumentation through a severely injured esophagus may cause:

• Bleeding
• Perforation

If enteral access is necessary:

Place the tube under endoscopic or surgical guidance when feasible.

Skin Decontamination

Immediately:

• Remove contaminated clothing
• Remove jewelry
• Remove retained chemical

For liquid alkali:

Copious water irrigation

should begin promptly.

For dry powder/quicklime:

• Brush away dry material first
• Then irrigate copiously

Do not attempt acid neutralization.

Eye Decontamination

Irrigate immediately—before any other detailed examination.

Use:

• Water
• Saline

Remove:

• Contact lenses
• Retained particulate matter

A topical ocular anesthetic may facilitate adequate irrigation when appropriate.

Continue irrigation until the ocular surface approaches physiologic pH and remains stable after irrigation pauses.

Then evaluate:

• Visual acuity
• Corneal epithelial defect
• Limbal ischemia
• Anterior chamber
• Intraocular pressure when appropriate

Significant alkali burns require:

Urgent ophthalmology consultation

Antidote

There is no specific antidote for alkaline caustic poisoning.

Management is based on:

• Immediate decontamination
• Airway support
• Injury assessment
• Surgical management when required
• Treatment of complications

Corticosteroids

Major modernization

The older text recommends corticosteroids for Grade II burns.

This is not supported as routine modern therapy.

A systematic review/meta-analysis of randomized trials found:

No demonstrated significant reduction in esophageal stricture formation with systemic corticosteroids. (PubMed⁠)

Earlier pooled clinical analyses likewise failed to support routine steroid therapy for Grade II caustic burns. (PubMed⁠)

Therefore:

Do not routinely give systemic steroids solely to prevent strictures.

Nuance

Selected pediatric protocols have investigated high-dose corticosteroids in specific Grade IIb injuries, so this remains an area of specialty debate.

If considered, it should involve:

• Pediatric gastroenterology/GI
• Medical toxicology
• Surgery

rather than automatic treatment based simply on “second-degree burn.”

Antibiotics

Routine prophylactic antibiotics are not indicated.

Use antibiotics when there is:

• Perforation
• Mediastinitis
• Peritonitis
• Aspiration pneumonia
• Documented infection
• Severe necrotic injury managed according to a surgical protocol

Antibiotics do not reliably prevent strictures.

Proton-Pump Inhibitors

PPIs are frequently used in significant upper-GI caustic injury.

However:

Evidence that they improve major outcomes or prevent strictures remains limited.

They may be reasonable as adjunctive acid suppression but are not antidotal therapy. (NCBI⁠)

Nutrition

Nutrition should be determined by injury severity.

Grade 0–I / selected IIa

If swallowing is comfortable and there is no significant injury:

• Oral intake may be resumed as clinically appropriate

Grade IIb–III

May require:

• Initial bowel rest
• Carefully planned enteral nutrition
• Jejunal access
• Occasionally parenteral nutrition

The goal is to maintain nutrition while avoiding unnecessary trauma to the injured esophagus.

Surgery

Emergency surgical consultation is required with:

• Perforation
• Peritonitis
• Mediastinitis
• Uncontrolled hemorrhage
• Extensive transmural necrosis
• Progressive shock attributable to GI necrosis

CT evidence of:

Absent mural enhancement

strongly suggests full-thickness necrosis and may indicate emergency resection. (PubMed Central (PMC)⁠)

The old recommendation to operate simply because endoscopy shows “Grade III” is too simplistic; depth of necrosis and clinical/CT findings now play a major role.

Stricture Formation

The most important delayed GI complication is:

Esophageal stricture

Risk is greatest after:

• Grade IIb injury
• Grade III injury

Strictures usually become clinically apparent after the acute healing phase, commonly beginning approximately:

3 weeks onward

Symptoms include:

• Progressive dysphagia
• Food impaction
• Regurgitation
• Weight loss

Stricture Management

First-line treatment for established esophageal strictures is generally:

Endoscopic dilation

using:

• Balloon dilation
• Bougie dilation

Repeat procedures are often necessary.

Complex/refractory strictures may require:

• Advanced endoscopic techniques
• Feeding access
• Surgical reconstruction

Routine prophylactic stenting to prevent strictures is not standard care.

Gastric Outlet Obstruction

Deep gastric burns can heal with fibrosis and produce:

• Early satiety
• Postprandial vomiting
• Weight loss
• Gastric retention

This may appear several weeks after the ingestion.

Long-Term Cancer Risk

Previous severe caustic injury is associated with increased risk of:

Esophageal squamous cell carcinoma

usually many years to decades later.

Published literature commonly reports development approximately:

30–40 years after injury, although the exact magnitude of risk is uncertain. (PubMed Central (PMC)⁠)

The older claim of a precise fold-increase should be interpreted cautiously because much of the evidence comes from older observational series.

Surveillance

Long-term surveillance is reasonable after major caustic esophageal injury/stricture, but:

There is no universally validated endoscopic surveillance schedule.

Follow-up should be individualized with gastroenterology.

Occupational Exposure – Sodium Hydroxide

The older workplace section requires one correction.

OSHA

PEL: 2 mg/m³ as an 8-hour TWA

NIOSH

REL: 2 mg/m³ CEILING

ACGIH

TLV: 2 mg/m³ CEILING

NIOSH IDLH

10 mg/m³

(OSHA⁠)

Thus, the old statement:

“ACGIH TLV TWA 2 mg/m³”

is incorrect; ACGIH lists a ceiling value.

Monitoring

Patients with significant injury should be monitored for:

• Airway edema
• Hypoxemia
• Bronchospasm
• GI hemorrhage
• Perforation
• Shock
• Metabolic acidosis
• Renal injury

Serial:

• Vital signs
• Respiratory examinations
• Abdominal examinations
• Laboratory studies

are appropriate according to severity.

Admission

Admit patients with:

• Intentional significant ingestion
• Drooling
• Dysphagia/odynophagia
• Persistent vomiting
• Chest/abdominal pain
• Stridor
• Respiratory distress
• Hematemesis
• Significant oral injury after concerning exposure
• Abnormal EGD/CT
• Grade IIb/III injury
• Hemodynamic instability

ICU care is appropriate for:

• Threatened airway
• Respiratory failure
• Shock
• Major hemorrhage
• Full-thickness necrosis
• Perforation

Disposition

A fixed historical:

“6-hour observation = safe discharge”

should not replace clinical risk assessment.

A patient after a clearly trivial accidental taste may often be discharged when:

• Completely asymptomatic
• Normal examination
• Swallowing normally
• Tolerating oral intake
• Exposure is clearly low-risk
• Reliable home observation is available

Intentional or concentrated alkali exposures deserve a much lower threshold for:

• CT
• Endoscopy
• Admission
• Multidisciplinary evaluation

Prognosis

Grade 0–I

Usually excellent.

Grade IIa

Generally favorable.

Grade IIb

High risk of:

• Esophageal stricture
• Prolonged nutritional problems

Grade III

High risk of:

• Hemorrhage
• Transmural necrosis
• Perforation
• Mediastinitis/peritonitis
• Shock
• Stricture
• Death

A key determinant of survival is early recognition of:

Full-thickness necrosis before catastrophic perforation occurs.

Important Pitfalls

1. Assuming “basic pH” automatically means a dangerous caustic

Corrosive potential depends on:

Concentration + titratable alkalinity + contact time

not pH alone.

2. Using pH 11.5 as an absolute cutoff

A pH above approximately 11–11.5 raises concern, but:

There is no universal safe pH threshold.

Evaluate the actual product and exposure.

3. Assuming a normal mouth means a normal esophagus

Absence of oral burns does not exclude severe distal injury.

(NCBI⁠)

4. Waiting for obvious airway obstruction

Progressive caustic edema can make late intubation extremely difficult.

Stridor/hoarseness/progressive edema → early airway planning.

5. Inducing vomiting

Never induce emesis.

6. Neutralizing alkali with acid

Do not give:

• Vinegar
• Citrus juice
• Other acidic neutralizers

The reaction may generate heat and worsen injury.

7. Automatically giving milk or water

Routine oral dilution is no longer recommended because clinical benefit is unproven and vomiting/distention may occur. (NCBI⁠)

8. Giving activated charcoal

Charcoal is generally not useful for isolated sodium/potassium hydroxide ingestion and may interfere with management.

9. Performing gastric lavage

Routine gastric lavage has no role.

10. Blindly inserting a nasogastric tube

Severely injured tissue may perforate.

Use guided placement when enteral access is required.

11. Automatically giving steroids for Grade II burns

Modern evidence does not show reliable prevention of strictures. (PubMed⁠)

12. Giving prophylactic antibiotics to everyone

Antibiotics are reserved for:

• Infection
• Perforation
• Mediastinitis/peritonitis
• Selected severe necrotic cases

13. Treating CT and EGD as interchangeable

They answer somewhat different questions:

EGD → mucosal injury

CT → transmural/extra-esophageal injury

A 2025 review concludes that the evidence is not yet sufficient to universally replace EGD with CT. (PubMed Central (PMC)⁠)

14. Assuming Grade III endoscopy automatically mandates resection

Modern surgical decision-making relies heavily on:

• Clinical status
• CT evidence of transmural necrosis
• Perfusion
• Perforation

not mucosal appearance alone.

15. Irrigating dry quicklime without first removing particulate

Dry calcium oxide reacts exothermically with water.

Brush off dry material first → then irrigate.

16. Missing delayed complications

Patients can initially recover and later develop:

• Esophageal stricture
• Gastric outlet obstruction
• Nutritional problems

17. Forgetting long-term cancer risk

Severe caustic injury/stricture increases the later risk of:

Esophageal squamous cell carcinoma

often decades later. (PubMed Central (PMC)⁠)

High-Yield Toxicology Pearls

Alkaline caustics = liquefaction necrosis with potentially deep tissue penetration

Think:

Lye ingestion → drooling/dysphagia + chest pain → deep esophageal injury ± perforation

Key points:

• Strong alkalis cause liquefactive necrosis
• Mechanism:
• Fat saponification
• Protein dissolution
• Deep tissue penetration
• Common agents:
• NaOH
• KOH
• Caustic drain/oven cleaners
• Cement/lime
• Hair relaxers
• pH >11–11.5 raises concern but is not an absolute toxicity threshold
• Concentration and titratable alkalinity matter
• Alkalis classically injure the esophagus
• Severe exposures may also injure stomach/duodenum
• Normal oral examination does not exclude esophageal injury
• Main emergency priorities:
• Airway
• Hemodynamic support
• Injury staging
• Progressive hoarseness/stridor → early intubation
• Do not induce vomiting
• Do not neutralize with acid
• Routine milk/water dilution is not recommended
• Activated charcoal has no routine role
• Gastric lavage has no role
• Avoid blind NG placement
• Significant exposure → EGD and/or contrast CT
• EGD is commonly performed within 12–24 h
• CT is particularly valuable for detecting transmural necrosis
• Absent mural enhancement on CT → major concern for full-thickness necrosis
• Grade IIb/III injury → high stricture risk
• Emergency surgery for:
• Perforation
• Mediastinitis/peritonitis
• Full-thickness necrosis
• Major hemorrhage
• Progressive shock
• Routine systemic corticosteroids do not reliably prevent strictures
• Routine prophylactic antibiotics are not indicated
• Esophageal strictures usually emerge weeks later
• First-line established-stricture therapy → endoscopic dilation
• Severe prior injury carries a later esophageal SCC risk
• Sodium hydroxide occupational limits:
• OSHA: 2 mg/m³ TWA
• NIOSH: 2 mg/m³ ceiling
• ACGIH: 2 mg/m³ ceiling
• NIOSH IDLH: 10 mg/m³
• No specific antidote

I can keep the next toxicology chapter in this same modernized, high-yield format.