WEL Substance Profile

Nickel — Workplace Exposure Limit Change

CAS: 7440-02-0 | Notation: Inhalable fraction, carcinogen (IARC Group 1 for nickel compounds, Group 2B for metallic nickel)

Current WES

mg/m³

New WEL (Dec 2026)

0.01

mg/m³

Change

-99%

reduction

Health Effects

Nickel compounds are classified as Group 1 carcinogens by IARC, with sufficient evidence of causing lung and nasal sinus cancer in humans. Metallic nickel is classified as Group 2B, possibly carcinogenic. Nickel is also one of the most common causes of allergic contact dermatitis, affecting approximately 10 to 15 per cent of the general population. Inhalation of nickel dust and fume causes occupational asthma through both allergic and irritant mechanisms. Chronic exposure leads to chronic rhinitis, sinusitis, and anosmia. Acute inhalation of high concentrations of nickel carbonyl, a volatile nickel compound formed during certain industrial processes, can cause fatal pulmonary oedema. Kidney toxicity has been documented in workers with chronic nickel exposure. The 99 per cent reduction in the exposure limit reflects growing evidence that health effects occur at much lower concentrations than previously recognised.

Where Exposure Occurs

Stainless steel and nickel alloy welding (all processes)Electroplating and nickel plating operationsNickel refining and smeltingGrinding and polishing stainless steel and nickel alloysBattery manufacturing (nickel-cadmium, nickel-metal hydride)Thermal spraying and hard-facing operations

What to Do Now

01Conduct personal air monitoring for nickel at all workstations where nickel-containing alloys are welded, cut, ground, or plated. The 99 per cent reduction from 1 to 0.01 mg/m³ is the second-largest limit change in the WEL transition after manganese. Virtually all operations that were compliant under the old limit will exceed the new WEL without significant additional controls.

02Install or upgrade local exhaust ventilation with high-efficiency source capture on all nickel-exposed workstations. For welding operations, on-torch extraction or extraction arms positioned within 150mm of the arc provide the most effective fume capture. For grinding and polishing, enclosed or semi-enclosed workstations with downdraft or cross-draft ventilation are required.

03Implement a comprehensive RPE program for all nickel-exposed workers. The magnitude of the limit reduction means that respiratory protection will be essential during the transition period while engineering controls are being upgraded. Powered air-purifying respirators with P3 particulate filters provide the highest protection factors for routine work. All RPE must be individually fit-tested.

04Establish health surveillance including baseline and periodic lung function testing, nasal examination, urinary nickel biomonitoring, and skin examination for nickel dermatitis. Biological monitoring of urinary nickel provides a complementary measure of absorbed dose that accounts for all exposure routes including dermal absorption.

05Evaluate process changes to reduce nickel exposure. Robotic or automated welding removes the worker from the fume plume. Closed plating systems with enclosed tanks and automated racking reduce vapour and mist exposure. Water-based cutting fluids reduce nickel-containing mist generation during machining of nickel alloys compared to oil-based fluids.

Monitoring Method

Personal air sampling using a calibrated pump at 2 L/min with an IOM inhalable sampler and mixed cellulose ester filter. Analysis by ICP-MS or ICP-OES after acid digestion. The extremely low WEL of 0.01 mg/m³ requires analytical methods with detection limits below 0.001 mg per sample — confirm with the laboratory that their method achieves adequate sensitivity.

Affected Industries

Metal Fabrication →Auto Body →

Manage the 99% Nickel Limit Reduction

EHS Atlas tracks nickel monitoring data against the incoming 0.01 mg/m³ WEL and automates health surveillance scheduling for welding and plating operations.