Synergist - June/July 2011

measurement, or both, that an equivalent or higher level of protection is being provided. This decision should be sufficiently documented. Note, too, that when exposure measurements are used to support a decision under REACH, the data set is expected to be representative and robust.

Multiple ESs, Single Workplace

Compliance with a single ES can be complicated. But very few, if any, manufacturing processes include only one substance. If a manufacturing process includes two REACH substances, the intended use will have to be sufficiently similar to two independently registered uses.

Let’s assume that the two sets of OCs are sufficiently similar. It is still possible that some RMMs are redundant, incompatible, or even contradictory, requiring the downstream user to determine whether a subset of the RMMs reasonably fits within the boundaries of the two ESs. If not, the user will need to either ask one or both manufacturers or importers to modify its ES or complete their own chemical safety assessment. Since the possibility of redundant, incompatible or contradictory RMMs increases with each additional ES, REACH compliance will take considerable effort for complicated manufacturing processes that need to comply with multiple ESs. And because of the staggered implementation of REACH, new eSDSs will continue to be made available for preregistered substances through 2018, and continuously for new substances and substances that cross new tonnage thresholds. This increases the likelihood that, after having conducted an assessment to meet one vendor’s RMMs, a downstream user could receive a new eSDS with additional ESs, requiring a reassessment.

Coexistence of DNELs and OELs DNELs (derived no effect levels) and OELs are quantitative estimates of “safe” levels for human exposure and are derived by applying safety factors to a no observable adverse effect level (NOAEL), a lowest observable adverse effect level (LOAEL), or another toxicological point of departure. However, the intended purpose of an OEL is to establish the acceptable limit of exposure in a workplace, while that of a DNEL is to establish the OCs and RMMs that define the safe use of a substance within a specific ES. As a

result, the obligation of downstream users, under the EU Chemicals Directive, is to maintain exposures below the OEL. Under REACH, the obligation for the downstream user is to implement the OCs and RMMs specified by the manufacturer or importer.

The mandatory inclusion of both the applicable DNELs and the national OELs (for the EU member state in which the safety data sheet is being provided) in section 8.1 of the new EU eSDS may well cause confusion. When both a DNEL and a national OEL are provided for a substance, the OCs and RMMs must be implemented, but exposures must be controlled to below the national OEL. When no national OEL exists and only a DNEL is provided, the OCs and RMMs must be implemented. It is good practice to monitor the resulting exposures, but the DNEL is not the default limit for exposure control. When other, non-national OELs, such as the ACGIH® TLVs® or AIHA® WEELs, differ from the DNELs, IHs should consider whether these consensus limits are more robust than the limits set by the manufacturer or importer. Of particular concern are DNELs from multiple sources that can vary significantly from one another. If there are no national or consensus OELs, the DNELs may be a reasonable default limit for control, but IHs should understand their intended uses, limitations, and how they were derived.

As mentioned earlier, downstream users may deviate from the OC and RMM recommendations of the manufacturer or importer. In this case, users must develop their own ESs and demonstrate, by either modeling or a robust set of sampling data, that the anticipated exposure associated with the alternative OCs and RMMs is less than the DNEL. However, the role of the DNEL ends with the finalization of the ES. If there is a national OEL for the substance, the workplace limit will be the OEL and not the DNEL.

DNELs are not intended to be, or re-
place, OELs. Rather, they are part of the
REACH assessment process designed to
establish OCs and RMMs. They also con-
veniently fill a gap that exists due to the
insufficient number of national and con-
sensus OELs. However, DNELs are devel-
oped by the manufacturer or importer,
and therefore may not have the scientific
rigor or broad peer review of national
and consensus OELs. The coexistence of
DNELs and OELs in a workplace will not
always be straightforward, so training on
this topic should be provided to all af-
fected individuals.

New Boundaries

Under REACH, the OCs and RMMs specified by the manufacturer or importer set a boundary around how a safe working environment can be established and maintained. These specifications can provide much-needed assistance to small- or medium-size enterprises that lack dedicated occupational health and safety resources. However, unless managed carefully, they can also limit a robust occupational health and safety program’s ability to maintain a safe working environment in a responsive and cost effective manner.

To be effective members of a REACH compliance team, IHs must develop three skill sets. First, they must cultivate a thorough understanding and a functional expertise with obligations of REACH, the concept of an ES, and the details of OCs and RMMs. Second, they must add exposure assessment skills to their repertoire, including an understanding of both sam-pling/analytical and modeling techniques. And finally, they must foster the art and science of deciphering OCs and RMMs and developing exposure control strategies that fit within their boundaries.

Robert Skoglund, PhD, DABT, CIH, is the senior laboratory manager for the Material EHS section of the 3M Corporate Medical Department and is a member of the leadership team responsible for REACH compliance.

Robert Roy, PhD, DABT is a lead toxicology specialist in the Toxicology Assessment and Compliance Assurance section of the 3M Corporate Medical Department and is responsible leading the development of 3M Exposure Guidelines and REACH DNELs. Dr. Roy is also a member of the AIHA WEEL committee.

Jocelyn Walton, MPH is a senior industrial hygienist in the Material EHS section of the 3M Corporate Medical Department and is involved in the development of CSRs, ESs, and eSDSs.

Perry Logan, PhD, CIH is the technical manager for the Industrial Hygiene section for 3M EHS Operations and leads the implementation of OCs and RMMs in 3M facilities in the European Union. Dr. Logan is currently President-Elect for the Academy of Industrial Hygiene, which promotes advancements to the professional practice of IH globally.