Do you need assistance?

Client Services Representatives are on standby.
Click "Start Chat" if you need assistance.

No Thanks Start Chat

DNELs Are Right Around the Corner

Industrial Hygienists, Analytical Laboratories Brace for Flood of New Exposure Limits

By Joe Unangst

Adopted in December 2006, the European Union’s (EU) Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation is the strictest law ever enacted on chemical manufacturing. REACH was designed to systematically identify the hazards and risks of chemicals, allowing for appropriate risk management measures by industry and, if necessary, providing for further regulatory action.

REACH requires EU manufacturers and importers to register substances they produce or import in quantities over 1 ton per year. The registration requirement applies to substances on their own, in preparations, and in articles. Timing and other factors affect the required registration date; some manufacturers needed to comply as early as June 1, 2008, while others have until June 1, 2018.

The next major registration deadline is fast approaching. By Dec. 1, 2010, the EU will require companies to register substances that will be manufactured or imported according to the following criteria:

  1. In quantities of 1,000 or more tons per year
  2. In quantities reaching 1 ton or more per year for substances classified as carcinogenic, mutagenic or toxic to reproduction (International Association for Research on Cancer Category 1 or 2)
  3. In quantities reaching 100 tons or more per year for substances classified as very toxic to aquatic organisms and which may cause long-term adverse effects in the aquatic environment

In addition, manufacturers and importers of chemicals that meet these criteria are required to calculate a new exposure limit, known as a Derived No-Effect Level (DNEL), as part of their chemical safety assessments for these substances. The publication of DNELs starting Dec. 1 may have far-reaching consequences for industrial hygienists, analytical laboratories, and other OEHS professionals.

Definition of a DNEL

Essentially, DNELs are new, scientifically derived risk assessment tools similar to OSHA PELs in the U.S. Annex One of REACH defines the Derived No-Effect Level (DNEL) as the level of exposure to the substance below which no adverse effects are expected to occur. It is therefore the level of exposure to the substance above which humans should not be exposed. DNEL is a derived level of exposure because it is normally calculated on the basis of available dose descriptors from animal studies such as No Observed Adverse Effect Levels (NOAELs) or benchmark doses (BMDs).

The number of companies required to calculate DNELs will grow over the next several years. By June 1, 2013, DNELs will be required for all chemicals manufactured or imported in excess of 100 tons per year; by June 1, 2018, the threshold falls to 1 ton per year. Once calculated, DNELs are published in the manufacturer’s chemical safety report for hazard communication. The intent of REACH is for DNELs be added to chemical labels.

DNELs are used in the risk characterization portion of a chemical safety assessment. They are benchmarks to determine adequate controls for specific exposure scenario risks. REACH specifies that DNELs “shall reflect the likely root duration and frequency of the exposure.” In cases where an assessment doesn’t have a threshold effect level—in other words, for substances that always have some effect at any level—REACH allows manufacturers to determine a Derived Minimal Effect Level (DMEL).

Implications Beyond the EU

One of the main reasons the EU developed REACH was that many substances have been manufactured and placed on the European market, sometimes in very large amounts, for which insufficient information exists about the hazards they pose to human health and the environment. Some concerns have been related to toxins in toys and polybrominated diphenyl ethers (PBDEs) in breast milk, for example, where the routes for exposure weren’t well defined in some cases for sensitive populations. REACH addresses many of these concerns by assuming that all chemicals are unsafe unless proven otherwise. The process to obtain environmental and human effects data on exposure to chemicals, once thought in the EU to be broken, is now considered fixed.

The REACH approach applies some pressure on the U.S. to develop a similar regulation. For example, several thousand chemicals in use today in the U.S. haven’t been studied, and government agencies are making little or no progress in addressing them. From a regulatory perspective, the existence of OSHA PELs and other occupational exposure limits might lead one to assume that substances for which no PEL exists do not need exposure levels. Of course, OEHS professionals have never assumed exposures to chemicals in any quantity to be safe without some evaluation, but few people in the general public would understand the risks associated with the thousands of chemicals used in commerce.

Developing a successful DNEL requires manufacturers or importers of chemicals to provide a valid study. The EU determined that the costs of registering chemicals and developing exposure assessments would be offset by decreased health-care costs associated with exposures. If more than one company manufactures or imports a particular chemical, the companies are required to collaborate prior to the chemical’s registration deadline. The REACH regulation estimates that, by the end of 2018, tens of thousands of new DNELs and other exposure limits will be generated.

Ultimately, DNELs will be listed on safety data sheets with other exposure limits. In the EU, the DNEL process may eventually replace some current occupational exposure limit processes; some countries are already using it as a default (unless the government believes lower limits are justified).

Some evidence exists that acceptance of DNELs, or similar limits, is inching its way into the U.S. and other countries. The Safe Chemicals Act of 2010, introduced in April by Senator Frank Lautenberg, implies a REACH-like approach to chemical manufacturers. The Safe Chemicals Act is intended to be a means for developing new exposure limits. Whether this bill will get off the floor remains to be seen. But if it passes, manufacturers will have to derive an assessment and permissible exposure level in the U.S., and the OEHS industry will see a flurry of activity to meet this requirement.

As hundreds and possibly thousands of DNELs are developed and published, IH and OEHS professionals will have an obligation to consider these new limits in their effort to protect workers. It would be inappropriate to ignore a standard such as a DNEL during a risk assessment. Eventually, the DNEL may very well become a de facto PEL in the U.S. for thousands of chemicals that have never been associated with a specific exposure level.

Questions about Methods

The spread of DNELs has the potential to require development of new methods of data collection and exposure monitoring. In practice, one doesn’t always know whether a compound can be effectively collected and quantitatively analyzed if no validation study has been performed on the method. Validation studies are exhaustive studies used to show how a compound can be accurately and precisely collected and quantitatively analyzed under varying conditions, including temperature, humidity, light and time. OSHA and NIOSH have performed validation studies on a few hundred compounds, but very few have been completed in the past decade.

When a new exposure limit (such as a DNEL) is derived for a compound with no validated method, an evaluation is necessary to determine the best method for obtaining data to protect the worker, public and environment. The method chosen will be much less regulated than methods associated with OSHA PELs or TLVs (where OSHA- or NIOSH-validated methods are available). IH and OEHS professionals will have to choose which approach to take when determining the exposure of compounds that have no validated method (and there will be many). Can you use a real-time instrument? Is there a detector tube method available? Can the concentration be reliably calculated based on mass balance or empirical data? Is the compound similar to a compound that is already tested using a validated method? Does a method need to be developed and validated for the compound?

Currently, all methods used in an AIHA-accredited laboratory are validated to some level, and most are fully validated OSHA or NIOSH methods. To fully validate a new method based on OSHA or NIOSH guidelines requires hundreds of analyses and special environmental chambers; each compound could require months of study. This process may be too costly for small-quantity chemicals, and alternative methods may need to be validated in other ways. The IH community has an opportunity to develop practical means for monitoring and providing data to demonstrate compliance with DNELs, which, to date, has not been well defined.

After November

No one knows for sure what will happen when DNELs go into effect. At AIHce 2010 in Denver, attendees from the EU indicated that little is expected to happen initially because the manufacturers and importers of chemicals exceeding 10,000 tons have already developed exposure plans and are monitoring their workers. Large manufacturers will have the data and the ability to help downstream users through the process, while small-quantity manufacturers or users will remain exempt for some time. But midsize companies will need to begin evaluating their exposures and the processes they use to protect workers. The effects on midsize companies will likely be felt more in 2013 or 2018 when the REACH threshold for calculating DNELs is lowered to include more manufacturers.

The EU does not have the same forces of liability exposure and government oversight that exist in the U.S. to implement these new exposure limits. A midsize company in the EU, with limited liability and minimal enforcement, may not be compelled to do much of anything initially. If a REACH-like law is passed in the U.S., liability would be more of an issue, but it would take time to get the new exposure limits into the hands of OEHS professionals. Passage of legislation similar to REACH would establish de facto PELs without the cost and political backlash of OSHA’s rulemaking process. And establishing new limits that have the force of law will have a significant impact on the need for OEHS professionals to find methods for monitoring new chemicals.

Even if the U.S. does not pass legislation similar to REACH, OEHS professionals who have DNELs listed on their material safety data sheets are going to have to address them as essentially de facto exposure levels. Workers will no doubt be concerned when they note a DNEL on a safety sheet that previously had none.

Good Monitoring Data

DNELs will also have an effect on analytical laboratories accredited by AIHA. Currently regulated chemicals have OELs or OSHA PELs and validated methods. Laboratories routinely perform the required analyses, and the data can be effectively used to protect workers. The introduction of new compounds puts the onus on analytical laboratories to develop new methods and provide OSHA validations so that the methods are defensible if the data are challenged. With chemical manufacturers starting to publish DNELs on Dec. 1, 2010, and adding new chemicals over the next eight years, laboratories need to start developing methods to provide data that protect workers.

What Next for Labs?

Laboratories must help educate our clients on the rules and regulations as they’re developing and which monitoring solutions may be available. They should discuss the sequence of registrations and the available methods with their multinational clients. Labs need to help IH professionals serving the manufacturing industry find valid and defensible monitoring methods with enough lead time to allow for full validation of a new method if necessary. The most practical solution should be used. It’s important for industrial hygienists to be ahead of the deadlines and gather the resources they’ll need to meet these new requirements.

For a current list of registered compounds, please visit

Joe Unangst is president and CEO of Galson Laboratories. He is a member of the AIHA-LAP, LLC Strategic Advisory Group. He can be reached at (888) 432-5227 or

About Galson Laboratories

Galson Laboratories provides services in every state and 38 countries. Galson Laboratories works under the principles of continuous improvement and has developed industry-leading programs for its clients such as FreePumpLoan™ and FreeSamplingBadge™. Galson Laboratories is accredited to ISO/IEC 17025:2005 by AIHA. AIHA is an official signatory of the Mutual Recognition Arrangement (MRA) with the International Laboratory Accreditation Cooperation (ILAC). Headquartered in Syracuse, NY, Galson Laboratories has offices in Charleston, SC, Alameda, CA, Clear Lake Shores, TX, and Stevens Point, WI.

Site Design by 2ndNature :: an interactive studio