NACE Compliance

BOTH. From the Net:

Traditionally, the Department of Government Services, Occupational Health and

Safety Branch, automatically adopted as occupational exposure limits the annual

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold

Limit Values (TLVs). In Newfoundland and Labrador, the regulatory excerpt for

this authority is found in Section 42(7)(6) of the Occupational Health and Safety

Regulations, 2009, which states:

An employer shall ensure that except as otherwise determined by the

division, a worker is not exposed to a substance that exceeds the

ceiling limit, short-term exposure limit or 8-hour TWA (time weighted

average) limit prescribed by ACGIH ;

Since the 1970s, the exposure limit for hydrogen sulfide (H2S) was 10 ppm (8-

hour TWA - time weighted average) and 15 ppm (STEL - short term exposure

limit). In 2010, the ACGIH revised the exposure limits for H2S to 1 ppm (TWA)

and 5 ppm (STEL). The basis and rationale for the changes can be found in the

2010 ACGIH Documentation for H2S.

With the adoption of the new 2010 H2S exposure limits, there has been concern

within some industries regarding the practicality of these limits. Currently, the

majority of intrinsically safe personal gas detectors on the market do not have the

capabilities to accurately measure in the parts per billion (ppb) range. While

there are some detectors available which do have these capabilities these

instruments have not been adequately validated for reliability and accuracy. The

only validated methods currently available involve the use of sampling pumps

and collection devices. This method of personal sampling is not always

appropriate for the detection of H2S due to the wait times for analysis, the ability

for concentrations to vary in a short period of time and the serious effects related

to elevated exposures.

The ACGIH has documented the following information relating to the effects of

H2S:

1000-2000 ppm Loss of consciousness and possible death

100 - 1000 ppm Serious respiratory, central nervous, and cardiovascular system

effects

150-200 ppm Olfactory fatigue

100 ppm Immediately Dangerous to Life and Health (IDLH) concentration

5-30 ppm Moderate irritation of the eyes

5-10 ppm Relatively minor metabolic changes in exercising individuals

during short-term exposures.

< 5 ppm Metabolic changes observed in exercising individuals, but not

clinically significant

5 ppm Increase in anxiety symptoms (single exposure)

5 ppm Start of the dose-response curve (short term exposure)

All ACGIH TLVs are health-based values. They do not consider economic

feasibility, technical feasibility or the availability of valid and reliable methods to

measure workplace exposures to determine compliance with the TLVs. In the

case of H2S, the exposure limits have advanced beyond the current industry's

detection capabilities in many applications.

The Occupational Health and Safety Division will not issue orders where the

violation is based on the 2010 ACGIH TLVs for H2S and there are technical

limitations in the sampling equipment currently available on the market.

OHS Officers and Industrial Hygienists will continue to enforce the 2009 TLVs for

H2S until further information becomes available.

The Department will continue to monitor (1) research and development relating to

H2S gas detection equipment, (2) the availability of acceptable methods and

equipment to determine compliance with the new 2010 ACGIH exposure limits,

and (3) other Canadian jurisdictions adopting ACGIH guidelines as regulatory

standards for occupational health and safety.

In the interim, industry is encouraged to consider using the 2010 ACGIH H2S

guidelines when evaluating specific workplace situations and conditions and

making risk management decisions.

The valve industry deals with NACE materials. Try Googling for

NACE MRO175 and the Valve Industry

Use of International Standard NACE MR0175/ISO15156 (Canadian Guide)

Materials of Construction, Bulletin T101-4, NACE MRO175 and the Valve Industry, Jamesbury Metso

NACE MR0103 WE HAVE USED FOR HYDROCARBON SERVICE.IM NOT SURE ABOUT CHEMISTRY AND COMPOSITION.