## Update of NIOSH Carcinogen Classification

and Target Risk Level Policy for Chemical Hazards in the Workplace NIOSH Carcinogen Policy

Paul A. Schulte, PhD Director, Education and Information Division

Public Meeting, December 16, 2013

1

## Why Update the Carcinogen Policy ?

 

### New scientific advances in risk modeling, biological mode of action, and analytical methods

 

### Receive peer and public input on the NIOSH 

### process
 

### Increase the transparency of the NIOSH process

2

## Current Intelligence Bulletin

 

### Carcinogen classification

 

### Target risk level for carcinogen RELs

 

### Analytical feasibility and engineering 

### achievability

3

## Carcinogen Classification: History

 

### Since 1978 NIOSH used “potential occupational 

### carcinogen ” as its highest designation

 

### Some dissatisfaction with that terminology

 Known carcinogens such as asbestos, benzene, and cadmium were mislabeled

 

### NIOSH requested public input in 2011

 

### Public meeting on issues in December 2011

 

### Currently: draft document on web for public/peer 

### review

 http ://www.cdc.gov/niosh/docket/review/docket240A/pdf/EID

CIB

- 11052013.pdf

4

## Carcinogen Classification: Features

 

### Utilizes NTP

, EPA , and IARC cancer classifications for chemicals

 

### Evaluates occupational relevance in terms of 

### exposure and applicability of the data

 

### Assigns Globally Harmonized System (GHS) category for hazard communication

5

## Occupational Relevance of

Carcinogen Classification

 

### Potential for worker exposure

 

### Applicability of evidence to occupational carcinogenicity

 Mode of action

 Route of exposure

6

### NIOSH Chemical Carcinogen Review Process

7

## Correspondence of Carcinogen Classification

with GHS Carcinogen Categories *

NTP RoC IARC EPA 1986 EPA 2005 GHS Category/ Hazard Phrase Known to be a human carcinogen Group 1

Carcinogenic to humans Group A Human carcinogen Carcinogenic

to humans Category 1A

Known human carcinogen Reasonably anticipated to be a human carcinogen Group 2A

Probably carcinogenic to humans Group B1 Probable human carcinogen Likely to be

carcinogenic to humans Category 1B

Presumed human carcinogen Group 2B Possibly carcinogenic to humans

– adequate in animals; inadequate in humans Group B2 Probable human carcinogen

Group 2B Possibly carcinogenic to humans

– limited animal evidence Group C Possible human carcinogen Suggestive

evidence of carcinogenic potential Category 2

Suspected carcinogen

8 * As interpreted by NIOSH

## Carcinogen Classification

Sample Determination: Benzene

 

### NIOSH occupational carcinogen

 

### GHS carcinogen category 1A: known human carcinogen

 

### B ased on:

 NTP: known to be carcinogenic to humans

 EPA: Group A: human carcinogen

 IARC : Group 1: carcinogenic to humans

9

## Carcinogen Classification

Sample Determination: Heptachlor

 

### NIOSH occupational carcinogen

 

### GHS carcinogen category 1B: presumed human carcinogen

 

### Based on:

 EPA: Group B2

- probable human carcinogen (sufficient data in animals)

 IARC: Group 2B

- possibly carcinogenic to humans (sufficient data in animals)

10

## Target Risk Level for Carcinogen RELs:

History

 Prior to 1995: lowest feasible concentration

 Determined by employers

 Employer evaluated technical and economic options
 In 1995: adopted a quantitative basis for RELs

 Based on quantitative risk evaluation

• Use mathematic models to evaluate exposure

- response relationships

• Extrapolate from animals to humans and from high doses to low doses

 Acknowledged residual risks

 Inherent in establishing an REL is a target risk level but no such level was specified

11

## Risk Levels in N ew NIOSH Carcinogen Policy

 

### NIOSH affirms scientific knowledge that the only 

### way to eliminate excess risk from carcinogens is to prevent exposure
 

### NIOSH advocates using safer alternatives and to substitute noncarcinogen chemicals whenever feasible

 

### Removing all carcinogens in commerce is impractical so guidance on reducing carcinogen exposures to workers is needed

 

### NIOSH will assess risks using quantitative methods when data are available

12

## Risk Levels in New NIOSH Carcinogen Policy

 

### Communicate an array of lifetime cancer risk for 

### exposures from 1/100 to 1/1,000,000

 Provides useful information to employers and workers to take preventive action
 

### NIOSH will identify a minimum level of protection

– this is 1 in 1000 risk level; to establish a REL a 

### target risk level is needed

 

### NIOSH advocates trying to achieve exposures resulting in risks lower than 1 in 1000

13

## Basis for Target Risk Level

 

### U.S. Supreme Court “Benzene Decision” characterized a range of risks between 1 in 1000 and 1 in a billion

 

### Implied that 1 in 1000 was a significant risk

 

### NIOSH will use the 1 in 1000 target risk level because it better relates to OSHA’s work in developing occupational exposure limits

 

### NIOSH will use mathematic models for 

### quantitative risk assessment

14

### NIOSH Precedent for Using 1 in 1000 Risk Level *


### 1990 1990 1991 1995 1998

2001 2002

* Includes health effects other than cancer 

### Benzene PEL (Testimony to OSHA) Cadmium PEL (Testimony to OSHA) 1, 3

- Butadiene PEL (Testimony to OSHA) Coal dust (REL) * 

### Diesel exhaust (Journal article/collaboration 

### with MSHA) * 

### Silica (Journal article

- risk assessment ) Silica (Journal article

- risk assessment) *

15

### NIOSH Precedent for Using 1 in 1000 Risk Level (cont’d) *


### 2007 2011 2013 2013

* Includes health effects other than cancer 

### Manganese ( Journal article

- risk assessment ) * 

### Titanium dioxide (RELs) Hexavalent chromium (REL) Diacetyl /2,3

- Pentanedione (Draft REL) *

16

### Additiona l Protections Afforded by Risk Assessment and Related Communications

 

### Use of 45

- year working lifetime

 

### Treats exposure

- response as linear at low doses

 Default assumption

 In some cases sufficient mode of action data may allow risk estimation based on non

- linear dose

- response models

17

## Low Dose Extrapolation

Risk

Exposure Linear

Sub

- linear

18

### Additiona l Protections Afforded by Risk Assessment and Related Communications

 

### NIOSH REL will be based on 95% lower confidence limit of the exposure corresponding to the target level of risk

19

## Confidence Interval

Risk

Exposure 95% confidence limit on exposure

20

### Additional Protections Afforded by Risk Assessment and Related Communications (cont’d)

 

### NIOSH guidance is that risks should be kept well below the REL. Lower exposure lowers the risk.

 

### NIOSH recommends alternatives when possible

 

### For these reasons the actual risk on which a REL is based will be less than 1/1000

21

## Analytical Feasibility and Engineering Achievability: History

 

### “. . . Engineering controls . . . should be used to control occupational exposures to the fullest extent feasible .” [1988]

 

### “NIOSH RELs will be based upon risk evaluations . . . and on an assessment of what levels can be feasibly achieved by engineering controls and 

### measured by analytical techniques.” [1995]

22

## Analytical Feasibility and Engineering Achievability: Issues

 

### Not all NIOSH RELs are health

- based

 

### Many NIOSH RELs are based on analytical feasibility

 

### NIOSH has made some evaluations of engineering feasibility or achievability, but has not routinely conducted quantitative analyses of the technical feasibility of achieving RELs

23

## Analytical Feasibility and

Engineering Achievability

 

### NIOSH will no longer establish carcinogen RELs relying on an evaluation of engineering controls, but will make an effort to provide control information

 

### Basis of NIOSH RELs

 Health effects (quantitative risk assessment)

 Analytical feasibility (measurement of chemical in the work environment)

24

## Analytical Feasibility and Engineering

Achievability: New RELs Policy

 

### For new RELs, NIOSH will distinguish between health

- based and analytical feasibility

- based RELs

 Health

- based RELs = REL

 RELs based on analytical feasibility = REL AF

2526

## Timeline

 

### Public meeting (December 16, 2013)

 

### Receive all public comments by February 13, 2014

 

### Receive all peer review comments by March 14, 

### 2014

 

### Anticipate completion of FINAL Cancer Policy in 

### 2014

27

### Carcinogen and RELs Policy Update Committee

 David Dankovic (EID)

 John Decker (OD)

 Charles Geraci (EID)

 Pius Joseph (HELD)

 Eileen Kuempel (EID)

 Thomas J. Lentz (EID)

 Qiang Ma (HELD)

 Kathleen MacMahon (EID)

 Lauralynn McKernan (EID)

 Paul Middendorf (OD )  Rick Niemeier (ret .)

 Andrea Okun ( O D )

 Faye Rice (EID)

 Teresa Schnorr (DSHEFS)

 Paul Schulte (EID)

 Christine Sofge (EID)

 Patricia Sullivan (DRDS)

 Mark Toraason (OD)

 Ainsley Weston (DRDS)

 Ralph Zumwalde (EID)

28

# Thank you!

29 

### For updates visit the NIOSH Carcinogen Policy web page:

http ://www.cdc.gov/niosh/topics/cancer/policy.html