Hexavalent Chromium in Welding Environment, Safety & Health

Hexavalent Chromium

Asphyxiation of

Welder on LNG

Construction Site

23 August, 2009

Statement

• Who:Mr. Harendra, Welder

• What:Found unconscious inside

a 24” stainless steel pipe.

Attempts to revive were

unsuccessful.

• Where:Train 7 53-XH0603

• When:09:30 August 23, 2009

Sequence of Events • Welding crew conducted Toolbox Talk and Task Instruction

Meetings.

• Two welders assigned to Joint #29

• Two welders & one helper prepared equipment

• Argon dam installed during fit up on Aug. 20

• Welders decided one work on Joint #29 24” and other work on Joint#98 16”

• Welder began Root & Hot pass welds on Joint #29

• Completed welds and called down to helper on lower level “You come up, I go In check and repair weld”.

• Helper went up to work level, took approx. 2-3 minutes

• Welder was inside 24” pipe. Helper called to him with no response

• Helper called for help from welders in adjacent area. They attempted to call with no response

• Helper went to Foreman on ground level to make notification

• Emergency services notified and responded

• Victim retrieved from pipe unconscious/unresponsive

• CPR attempted but unsuccessful

Purge Dams for Argon Purging

Re-Creation

Victim’s last known position

Re-Creation

Position of Helper when last saw Victim

Findings • No evidence that the victim intended harm to

himself

• No evidence that the victim fell into the pipe

• Evidence indicates the victim entered pipe on his own to inspect and repair his weld

• Tools in possession are TIG torch, filler wire and cell phone (light)

• Re-creation indicated person of similar size can move relatively easily inside 24” (ID 22”) pipe

• Two welders assigned to the task but separated without direction from supervision

Re-Creation

Findings (cont.) • No Confined Space Entry was required to

complete this job. (External welding only)

• 10.2% Oxygen measured approx. 20 minutes after entry by the victim

• Awareness on hexavalent chromium and around inert gases needs improvement

• Other welders interviewed indicated they “might” go into a pipe to check and repair weld

• Similar incidents have occurred at other locations within the industry

• The victim had excellent history as a welder and employee

Findings (cont.) • ISO indicated line 100% radiography

• Weld passed Radiography

• No Method Statement/JSA that would apply to this task.

• No record of confined space, hexavalent chromium or argon/inert gas training for the victim

• HSE Training Matrix inconsistencies between contractors

• 9 Welders & 5 helpers assigned to one Charge Hand

• Only Helper had Confined Space Training

Causal Factors & Root Causes Entered 24” oxygen deficient

atmosphere to inspect and repair

weld

No Training – Decided not to train

based on training matrix. Training

based on task.

“Labels” Needs Improvements–

No warning/labels on confined

spaces

Enforcement Needs

Improvement-Compliance with

site procedures

Corrective Action Needs

Improvement–Previous external

incidents

Causal Factors & Root Causes

(Cont.) No Evidence of Confined Space,

Hexavalent Chromium or Inert

Gas Training for Welder

Decided Not to Train based on

training matrix. Training based on

task.

Communication Not Timely –

Training Matrix Update

IP and Welder #2 decide to split

up after assignment

Supervision during work needs

improvement

Charge Hand had large Span of

Control

Administrative Control not used –

Not following Resource Control

Guidance

Causal Factors & Root Causes

(Cont.) Task Instruction did not include

any information about confined

spaces, hexavalent chromium

or inert/argon gases

Pre-Job Briefing Needs

Improvement

Corrective Actions

• Provide awareness training on confined

spaces for all field workers

• Provide confined space entrant, attendant,

and supervisor training for all welders and

pipefitters

• Revise current Safety Induction training to

improve C.S. and hexavalent chromium

and inert gases hazard awareness

• Provide training to all welders on

hexavalent chromium, inert/argon gas

hazards

Corrective Actions Cont.) • Post signage and barrier with confined

space warning on all pipe opening 16” and greater.

• Add to the Golden Rules list “Entry into a Confined Space without a permit”

• Develop a process to implement “hard actions” based on external incidents. Specifically fatalities

Corrective Actions (Cont.)

• Revise HSE training matrix to require CSE

training for all welders

• “Scrutinize” training matrix for gaps

• Improve document control delivery

process

Corrective Actions (Cont.)

• Establish a clear rule for

worker/supervision ratio and develop

guidelines including considerations for

geographical spread

• Include in the Sr. Mgmt Walk thru

questions about supervisor

interaction/visibility with workers

Corrective Actions (Cont.) • Revise Pipe Erection Method Statement/JSA to

address welding and hexavalent chromium, inert/argon gases

• Create a process to Update Method Statements/JSA with information from external fatality incidents that have application to this work site

• Include in Task Instruction (TI) audits & training material the use of Method Statements/JSA’s by supervision to create TI’s

• Include in TI audits that TI’s are completed at the Task Location

Hexavalent

Chromium

in Welding

Environment,

Safety &

Health

Background Information – What

is Chromium?

• Chromium is a naturally

occurring element

• Contributes to hardness and corrosion resistance

• Commonly used in manufacturing activities such as:

– Steel hardening; and

– Electroplating

– Paints

• Commonly used as a pigment in coatings such as paint

Background Information – What is

Cr(VI)? • Hexavalent Chromium is produced when

chromium containing materials are heated

to an extreme temperature

• Cr(VI) is a toxic material

Background Information – Who is

Affected by Cr(VI)?

• The primary industries affected by

Cr(VI) include:

– Metal alloy fabrication and installation;

– Heavy duty coatings and paint production and

application; and

– Chrome electroplating

– Wood treating

Hexavalent Chromium in

Construction Uses Hexavalent Chromium Chemicals

Stainless Steel and

Other Chrome Metals

Hexavalent chromium is by-product when

stainless steel is cast, welded, or torch cut

Wood Preservation Chromium trioxide

Abrasive Blasting Grit may have (CrIV) as can the material

that is blasted.

Pigments for paints,

inks, and plastics

Lead chromate (chrome yellow, chrome

green, molybdenum orange) zinc

chromate, barium chromate, sodium

chromate

Anti-corrosion coatings

(chrome plating, spray

coatings)

Chromic trioxide (chromic acid), zinc

chromate, barium chromate, calcium

chromate, sodium chromate, strontium

chromate

Common Potential Cr(VI) Exposure

Activities • The most common potential exposures

found at construction projects are:

– Welding & cutting operations involving

chromium metals

– Welding & cutting operations on chromium

paints

– Spray painting chromate or chromic oxide

coatings such as paints

– Abrasive blasting with contaminated grit or on

Cr(VI) contamination

– Burning or cutting chemically treated wood

Health Effects of Cr(VI)

• Cr(VI) is considered a lung carcinogen

and requires compliance with:

– OSHA’s Occupational Exposure to

Carcinogens/Teratogens/Mutagens Core

Process Number 317.


• Cr(VI) enters the body by:

– inhalation

– Ingestion

– absorption through the skin.


• Inhalation

– Cancer (lung)

– Nasal septum ulcers & perforation

– Asthma

– Irritation (nose, throat, lungs)

– Nosebleeds

– Teeth Discoloration

– Death

Health Effects of Cr(VI) • Hodgkin’s Disease (all

routes)

• Leukemia (all routes)

• Bladder disease

• Reproductive

disorders

• Kidney disease (all

routes)

• Skin Ulceration &

irritation

• Eye Irritation

OSHA History • 1943: First exposure standard set at 52

µg/m3

• 1971: OSHA adopts 52 µg/m3 standard

• 1993: OSHA petitioned to reduce PEL

• 2003: OSHA ordered to lower PEL standard

• Feb. 28, 2006: Final revised standard issued

• May 30, 2006: Implementation begins

• November 26, 2006: Required to be in full

compliance with OSHA Standard (except

engineering controls)

Regulatory Information

OSHA Chromium Standards

Promulgated in 2006

• 1910.1026 – General

Industry

• 1915.1026 –

Shipyards, Marine

Terminals, and

Longshoring

• 1926.1126 –

Construction

OSHA Regulation 1926.1126

Components

• Lower personal exposure limits;

• Exposure Assessment Schedules;

• Engineering & Work Practice Controls;

• Personal Protective Equipment Controls;

• Hygiene Areas & Practices;

• Medical Surveillance; and

• Communication of Hazards to Employees;

OSHA’s Hexavalent Chromium

Program • OSHA Permissible

Exposure Limit (PEL)

– 5 µg/m3 as an 8-hour

Time Weighted

Average (TWA)

• OSHA Action Level (AL)

– 2.5 µg/m3 as an 8-hour

TWA

• OSHA’s target is to stay

below the 2.5 µg/m3

Action Level when

feasible


Program

• Exposure Determination

The 8-hour TWA will be determined by:

1.Initial Monitoring; or

2.Historical Data; or

3.Objective Data.


Program • Initial Monitoring

– Will be conducted to determine the 8-

hour Time Weighted Average (TWA);

– Samples will be collected from

workers breathing zone;

– Will be collected to accurately

characterize full shift exposure on

each shift, for each job classification,

in each work area;

– Representative sampling will be

conducted so that samples will be

collected from employee(s) expected

to have the highest Cr(VI) exposure.

OSHA’s Hexavalent Chromium Program

• Periodic Monitoring

– Is not required if initial exposures are below 2.5

µg/m3;

– Is not required if initial exposures are below the AL

and another monitoring event, taken at least seven

days later, confirms the result;

– Is required every 6 months if exposures are above

the AL but below the PEL;

– Is required every 3 months if exposures are above

the PEL; and

– Is required if there are changes in the production

process, raw materials, equipment, employees, work

practices, or control methods that may result in

exposure to Cr(VI).


Program • Notification of Air Monitoring Results

– If Employee Exposure exceeds the OSHA

PEL of 5 µg/m3, air monitoring results will be

posted at the job site or will be given to the

employee in writing, as soon as possible, but

no more than 5 working days later after

results have been received.

– Employees will also receive written

notification of the corrective actions being

taken to reduce exposures to or below the

OSHA PEL.


Program • Medical Surveillance

– Provided at no cost to employee;

– For employees who are or may be exposed to

Cr(VI) at or above 2.5 µg/m3 for 30 or more days

in a 12-month time period;

– Annually

– For employees experiencing signs or symptoms

of health effects associated with Cr(VI) exposure;

– Within 30 days after initial assignment or if

exposed during an uncontrolled release; and

– At the termination of employment.


Program • Medical Surveillance -

Contents of Exam

– Medical & work history with

emphasis on past, present,

and future exposure to

Cr(VI);

– History of respiratory

dysfunction, asthma,

dermatitis, skin ulceration,

nasal septum perforation,

and smoking status; and

– Physical exam of the skin

and respiratory tract.


Program • Medical Surveillance – Physician or

other licensed health care professional

(PLHCP) Statement

– Will provide a written medical opinion within

30 days of the exam and will state:

• Any detected medical conditions that would place

the employee at risk if further exposed to Cr(VI);

• Limitations to employees exposure to Cr(VI) or use

of PPE; and

• A statement that the results of the medical exam

have been explained to the employee.


Program • Respiratory Protection is

needed:

– When engineering and work

practice controls do not

reduce worker exposures

below the PEL of 5.0;

– During installation of

engineering and work

practice controls;

– During maintenance and

repair activities;

– During emergencies


Program • Personal Protective Equipment - Selection & Use

– Skin and eye contact must be assessed to

determine if protective clothing is necessary.

Certain activities will require protective clothing

(e.g., painting, abrasive blasting);

– If protective clothing is determined to be needed,

the protective clothing must be removed at the end

of shift or at the completion of the task involving

Cr(VI);

– Do not allow items contaminated with hexavalent

chromium to be removed from the workplace until

properly cleaned or processed.


Program • Decontamination and

Housekeeping

– Decontamination of outer garments and

equipment is necessary whenever

reusable protective clothing is required;

– Decontamination of outer garments and

equipment is necessary whenever an

Exclusion Zone has been established;

– Outer garments and protective clothing

shall be either HEPA vacuumed or wet-

wiped;

– Dry sweeping and compressed air are

not acceptable ways to clean or remove

Cr(VI) debris and contamination.


Program • Change Rooms

– When PPE is required due to a Cr(VI) skin hazard, change

rooms will be provided with separate storage facilities for

PPE and street clothes to prevent cross-contamination.

• Washing Facilities

– When skin contact with Cr(VI) occurs, employees must wash

their hands and faces at the end of the shift and prior to

eating, drinking, smoking, chewing tobacco or gum, applying

cosmetics, and using the toilet.

• Eating and Drinking Areas

– Must be maintained free of Cr(VI)

– Employees must not enter with PPE or other contaminated

equipment


Program

• OSHA requires use the standard

industrial hygiene controls to help

eliminate or reduce exposure to Cr(VI):

– Engineering Controls – first level of protection

– Administrative Controls – second level of

protection

– Personal Protective Equipment – last level of

protection

• Engineering Controls

– Substitution: substitute chromium-containing

materials with non-chromium materials or

substitute with a material containing less

chromium

– Ventilation: used to remove harmful fumes

and gases. Two types of ventilation

strategies include:

• General Dilution

• Local Exhaust


Program


Program

• Engineering Controls: General Dilution

Ventilation


Program • Engineering Controls: Local Exhaust

Ventilation

– Ventilation Bench

– Local exhaust hood

– On-Gun Fume Extractors


Program • Administrative Controls

– The following are examples of Administrative Controls

that will be implemented on Construction Sites:

• Surface Coating Removal Prior to Welding or Torch

Cutting

– Remove all surface coating to no less than 4

inches on either side of the proposed weld.

– Prohibit use of power grinders as a tool to

remove surface coatings.

– Use a containment system to collect paint chips.

• Employee Training and Written Safety Plans

• Demarcated and Posted Exclusion Zones


Program

• Administrative Controls – continued

• Equipment and Surface Cleanup

– No dry shoveling, sweeping, or brushing

– Distance maintained between cross-contamination

activities (grinding and welding)

• Personnel Decontamination

– When protective clothing is required a dirty change

room and a contamination-free street clothing change

room shall be established

– Wash hands and face before eating, drinking,

smoking, or applying cosmetics

• Air Monitoring and Medical Surveillance

• Work Practices such as Wet Methods


Program • Exclusion Zones

– Area where an

employee’s exposure to

airborne concentrations of

Cr(VI) exceeds, or may

exceed the OSHA PEL of

5 µg/m3.

– Area boundaries must be

clearly demarcated using

signs and barricades.

– Access in the area is

restricted to authorized

personnel only.


Program • Exclusion Zone warning signs must

include the following wording:

DANGER

HEXAVALENT CHROMIUM

CANCER HAZARD

AUTHORIZED PERSONNEL ONLY

RESPIRATORS REQUIRED IN THIS AREA


Program • Disposal

– Cr(VI) contaminated materials must be

collected and disposed of in sealed,

impermeable bags or other closed,

impermeable containers

– Bags or containers of Cr(VI) waste will display

a label with the following wording:

DANGER

CONTAINS HEXAVALENT CHROMIUM

AVOID CREATING DUST

CANCER HAZARD

Hexavalent Chromium

Craft Supervisor and

Employee Training

Welding Processes

Cr(VI) Fume Generation in Materials

that Contain Chromium • The welding and cutting processes that typically

generate Cr(VI) fume levels above the PEL are:

– SMAW or “stick” welding

– Flux cored arc welding (FCAW)

– Arc Gouging

– Plasma Arc Cutting

– Torch cutting

– Oxy lance

This applies to base and filler metals that have 5% or

greater chromium content.

Cr(VI) Fume Generation

• The welding processes that typically

generate Cr(VI) fume levels below the

PEL are:

– STT welding

– GMAW (MIG welding)

– GTAW (TIG welding)

– Grinding

Specific Guidance for Welding &

Cutting

• Start work with a half facepiece respirator

and local exhaust ventilation.

• If ventilation is not feasible, start work with

a PAPR welding hood

The following requirements apply to SMAW, FCAW, arc gouging, torch cutting, and plasma cutting with metals that contain 5% chromium or greater:


Cutting Con’t • Start work within an established Exclusion

Zone

• Conduct initial air sampling

• Adjust controls based on air sampling

results

• Medical surveillance may be required

when this work is conducted for 30 or

more days per year

• Worker & Supervisor Training


Cutting

• Chromium Awareness Training.

• Conduct initial air monitoring and make

adjustments based on the results.

The following requirements apply to GTAW, GMAW, & STT involving chromium-containing materials, and it applies to all other welding & cutting process with less than 1% chromium:

Controlling Chromium Hazards Examples of Local Exhaust Engineering

Controls:

Portable Smoke Eaters

Fume Extraction Welding Guns

Important: Keep the hood within 10 inches

Local Exhaust for

Confined Space Welding • Fans or Venturi eductors

• Ducts

• Hoods

Mechanical Dilution Ventilation Consist of fans/blowers and flex

duct

Controlling Chromium Hazards Examples of Respirators for Welders:

Half facepiece Powered Air

Purifying Respirator

Documents

Hexavalent Chromium in Welding Environment, Safety & Health