Finvest
CLH Environmental Services · Hazardous waste · Recycling · Industrial services · Thesis updated June 13, 2026

Guidance rose, but the price still matters

01 Running thesis

Raised guide, higher bar

Clean Harbors looks stronger after Q1. Management lifted its full-year 2026 adjusted EBITDA guide, a profit measure before interest, taxes, depreciation, and amortization, by $40 million to a $1.24 billion to $1.30 billion range. The midpoint is now $1.27 billion.

The biggest change is SKSS. That segment sells re-refined oil products, so investors used to worry that weak base oil prices could crush profits. In Q1 2026, SKSS adjusted EBITDA rose 16.7% even though revenue fell 7.1%. Management also raised the segment’s 2026 adjusted EBITDA target to about $165 million and said it wants to keep charging customers to take used oil instead of paying for it.

The bull case is that Clean Harbors owns hard-to-copy waste assets and is getting more value from both PFAS cleanup work and used oil collection. The bear case is not gone. Industrial Services is still weak, base oil prices can move fast, and the stock still has to earn its price after the guidance raise.

May 2026Management raised full-year 2026 adjusted EBITDA guidance by $40 million to a $1.27 billion midpoint. SKSS was the main surprise, with its 2026 adjusted EBITDA view raised to about $165 million.
Feb 2026Management introduced 2026 adjusted EBITDA guidance of $1.20 billion to $1.26 billion and adjusted free cash flow guidance of $480 million to $540 million. A three-year, $110 million PFAS contract added a clearer growth catalyst.
Oct 2025Environmental Services stayed strong and SKSS showed a more stable profit floor, but management reduced 2025 adjusted EBITDA guidance. The new $210 million to $220 million SDA project added long-term upside and execution risk.
Jul 2025Q2 showed a split picture. Environmental Services kept growing, while SKSS revenue and adjusted EBITDA fell, leaving the thesis dependent on proof that the charge-for-oil strategy could stabilize profits.
02 Business model

Hard permits, sticky waste

Clean Harbors makes money when companies need waste handled safely. That includes collecting it, moving it, treating it, burning it in incinerators, or putting it in landfills. Hazardous waste is not an easy market to enter because permits, safety rules, and local approval are hard to get.

Environmental Services is the core business. It benefits when factories, chemical plants, government sites, and other customers create waste that must go to approved sites. Tight hazardous waste capacity gives Clean Harbors real pricing power, especially in incineration and landfill services.

SKSS is different. It collects used oil, re-refines it into base oil and lubricants, then sells those products. The profit depends on the gap between what Clean Harbors earns or pays to collect used oil and what it can sell refined products for. The charge-for-oil model has improved that gap, but base oil prices still matter.

03 Product portfolio

What Clean Harbors sells

Cash cow

Technical Services

This is the high-value waste disposal arm, built around incinerators, landfills, and treatment sites. Q1 growth came from stronger landfill volumes and remediation projects.

Steady

Field and Emergency Response Services

Crews go on-site for cleaning, decontamination, spills, storms, and other urgent work. HEPACO expanded this capability.

Steady

Industrial Services

This group handles turnaround and maintenance work for refineries and industrial plants. It is the weak spot right now because customer projects have been short and lower value.

Steady

Safety-Kleen core services

These are containerized waste, vacuum, and parts washer services for a wide customer base. Q1 2026 revenue grew from better pricing and higher volumes.

Cash cow

Used oil collection

Clean Harbors collects used oil from auto shops and industrial sites. Higher pricing for waste oil collection added $13.9 million of Q1 2026 revenue versus the prior year.

Option

Re-refined oil and lubricants

SKSS turns used oil into base oils and blended lubricants. The segment can earn more when base oil prices rise, but revenue can fall when product pricing or volumes weaken.

Growth engine

PFAS cleanup and filtration

PFAS are long-lasting chemicals that customers need to test, filter, and dispose of. Management now expects PFAS-related revenue growth of 25% to 35% in 2026.

04 Business segments

Two engines, one bigger

Environmental Services86%modest
Safety-Kleen Sustainability Solutions14%declining

Segment mix uses Q1 2026 direct revenue from the March 31, 2026 Form 10-Q. Environmental Services is much larger, while SKSS has smaller revenue but rising profit expectations.

05 Risk factors

What could go wrong

SKSS margin gives back gains

High impact · Medium odds

SKSS had a strong Q1 because charge-for-oil pricing and higher base oil prices helped profit. A sharp fall in base oil prices could pressure the segment, even if management keeps trying to charge customers for used oil collection. The new $165 million 2026 segment adjusted EBITDA target raises the bar.

We watchWatch SKSS adjusted EBITDA versus the roughly $165 million 2026 target and watch base oil pricing.

Industrial Services stays weak

Medium impact · High odds

Industrial Services revenue fell by $19.8 million in Q1 2026 because demand for maintenance and turnaround work was lower. Management did not build a second-half recovery into the raised guide, so any rebound would help. A deeper industrial slowdown would still hurt Environmental Services growth.

We watchWatch quarterly Industrial Services revenue and customer spending in refineries, chemicals, and manufacturing.

PFAS work disappoints

Medium impact · Medium odds

PFAS is a clear growth path, and management raised its 2026 growth view to 25% to 35%. The company also won a three-year, $110 million PFAS water filtration contract at Pearl Harbor. The open question is how much profit that work carries and how steady the project schedule will be.

We watchWatch PFAS revenue growth, contract timing, and management comments on margins.

M&A and buybacks compete for cash

Medium impact · Medium odds

Clean Harbors paid $131.8 million in Q1 2026 to acquire certain businesses from Depot Connect International. It also had $574.4 million left under its share repurchase program at March 31, 2026. With adjusted free cash flow guidance near $520 million at the midpoint, management must balance deals, buybacks, and growth spending.

We watchWatch acquisition spending, share repurchases, and adjusted free cash flow versus guidance.

Big projects run late or over budget

Medium impact · Medium odds

Clean Harbors plans a Solvent De-Asphalting unit near its East Chicago re-refinery. The expected project cost is $210 million to $220 million, with completion expected in 2028. The company also guided 2026 net capital spending to $460 million to $520 million, so execution matters.

We watchWatch SDA project spending, completion timing, and whether management keeps the expected EBITDA contribution intact.
06 Quick answers

In one breath

What does Clean Harbors do?

Clean Harbors collects, treats, and disposes of hazardous and non-hazardous waste. It also collects used oil and re-refines it into base oil and lubricants.

Why does Clean Harbors have a moat?

The moat comes from permits, safety rules, and a network of incinerators, landfills, and treatment sites that are hard to copy. Customers need trusted outlets for risky waste, and there are not many large providers.

Why is PFAS important for Clean Harbors?

PFAS cleanup creates more testing, filtration, transportation, and disposal work. Management now expects PFAS-related revenue to grow 25% to 35% in 2026.

What is the biggest risk to the thesis?

The biggest risk is that the newer profit floor in SKSS fails if base oil prices reverse and charge-for-oil pricing weakens. A longer industrial slowdown would also weigh on Environmental Services.