Carcinogenic substances (CMR) in Germany: duties, exposure register and protective measures

What are carcinogenic substances (CMR substances)?

CMR substances are hazardous substances that can cause cancer (carcinogenic), damage genetic material (germ cell mutagenic) or impair reproduction (toxic for reproduction). The special duties of the German Hazardous Substances Ordinance (Gefahrstoffverordnung, GefStoffV) apply to categories 1A and 1B: category 1A means the effect is known in humans, category 1B that it is presumed, usually based on animal studies. Category 2 substances are only suspected and do not fall under the special rules of Sections 10 and 10a.

• Carcinogenic

  Category 1A or 1BH350 “May cause cancer”, H350i “May cause cancer by inhalation”

  Category 2 (suspected)H351

• Germ cell mutagenic

  Category 1A or 1BH340 “May cause genetic defects”

  Category 2 (suspected)H341

• Toxic for reproduction

  Category 1A or 1BH360 “May damage fertility or the unborn child”

  Category 2 (suspected)H361

Such products can be recognised by the “health hazard” pictogram (GHS08) and the H statements in section 2 of the safety data sheet. Under Section 2 (3) GefStoffV, mixtures above the concentration limits of the CLP Regulation also count as carcinogenic, as do activities and processes designated as such in Technical Rules – TRGS 906, for example, lists activities involving exposure to hardwood dust or respirable quartz dust. Other examples are benzene, chromium(VI) compounds and formaldehyde; asbestos is additionally covered by Sections 11 and 11a.

Duties at a glance: Sections 10 and 10a GefStoffV

The special protective measures are set out in Section 10, the recording, notification and information duties in Section 10a GefStoffV. Older documents often still refer to Section 14 for the exposure register – today that section only covers operating instructions and safety instruction.

• Check substitution and give it priority

  Legal basisSection 6 (1) no. 4, Section 7 (3) GefStoffV

• Closed system, otherwise minimise exposure in line with the state of the art

  Legal basisSection 10 (1) GefStoffV

• Determine exposure by measurements or other suitable methods

  Legal basisSection 10 (2) no. 1 GefStoffV

• Demarcate and mark work areas and restrict access

  Legal basisSection 10 (2) nos. 2 to 4 GefStoffV

• Action plan if the exposure limit is exceeded or in the medium-risk range

  Legal basisSection 10 (5) GefStoffV

• Keep and retain the exposure register, hand over an extract

  Legal basisSection 10a (1) to (3) GefStoffV

• Notify the authority

  Legal basisSection 10a (5) GefStoffV

• Inform employees immediately after unforeseen exposure or an accident

  Legal basisSection 10a (6) GefStoffV

Special protective measures under Section 10 GefStoffV

1. 1

   Substitute

   Substitution comes first. If you do without a technically possible substitute although Section 10 measures are needed, you must justify this in the risk assessment (Section 6 (8) no. 3 GefStoffV).

2. 2

   Closed system

   If substitution is technically impossible, CMR substances must be manufactured and used in a closed system. If that is not possible either, exposure must be minimised in line with the state of the art – the higher the exposure, the more urgent the measures.

3. 3

   Determine exposure

   Exposure must be determined by workplace measurements or other suitable methods – also so that increased exposure after an accident or unforeseeable event is detected quickly.

4. 4

   Demarcate and mark areas

   Work areas with exposure are demarcated and marked with the prohibition signs “No access for unauthorised persons” and “No smoking”. Only employees who need to work there and are competent or instructed for the task may enter. Where a published occupational exposure limit is met, demarcation and marking are not required.

5. 5

   Do not recirculate extracted air

   Air extracted from these areas must not be returned to them – unless it is adequately cleaned using recognised methods or equipment.

If the occupational exposure limit is not met or an activity falls in the medium-risk range, the duration of exposure must be reduced as far as possible and suitable respiratory protection provided (Section 10 (3)). Employees must wear personal protective equipment in particular if the exposure limit is exceeded or in the high-risk range (Section 10 (4)). For carcinogenic and germ cell mutagenic substances, an action plan with measures, the targeted reduction in exposure and a timeframe is also required (Section 10 (5)).

The risk-based concept of TRGS 910

For many carcinogens there is no concentration below which no effect can be ruled out. TRGS 910 therefore sets an acceptable concentration (Akzeptanzkonzentration) and a tolerable concentration (Toleranzkonzentration) for individual substances. Both correspond to a defined additional cancer risk after 40 years of daily exposure at work and apply as an eight-hour shift average (Section 2 (8a) and (8b) GefStoffV, TRGS 910).

• Low risk

  LimitExposure up to the acceptable concentration (acceptable risk 4:10,000 for a transitional period, target 4:100,000)

  ConsequencesRisk considered low and acceptable; the duty to minimise still applies

• Medium risk

  LimitBetween the acceptable and the tolerable concentration

  ConsequencesReduce exposure time, provide respiratory protection, action plan (Section 10 (3) and (5))

• High risk

  LimitAbove the tolerable concentration (tolerable risk 4:1,000)

  ConsequencesNot tolerable: wear PPE, notify the authority, activity only in line with a published rule (Section 10 (4) and (6), Section 10a (5))

An example from TRGS 910: for benzene, the acceptable concentration is 0.2 mg/m³ (0.06 ppm) and the tolerable concentration 1.9 mg/m³ (0.6 ppm). Short peaks above the tolerable concentration are limited by an excursion factor, 8 by default; there are no short-term values for the acceptable concentration.

Exposure register: content, retention and handover

The exposure register (Expositionsverzeichnis) is meant to show, in the event of a later illness, how high and how long someone's exposure was – cancer often appears decades later. It must include employees for whom the risk assessment shows a health risk from CMR substances of category 1A or 1B (Section 10a (1) GefStoffV); details are set out in TRGS 410, revised in 2026. The activity and the level and duration of exposure are mandatory. So that the data can still be attributed later, in practice it should include:

• Name and date of birth of the employee, company and work area
• Hazardous substance with CAS or EC number, or the carcinogenic activity
• Period of the activity, plus duration per shift and frequency
• Level of exposure as a measured value or classification, such as “below the acceptable concentration”, without taking PPE into account
• Assessment criterion and method, such as workplace measurement or transfer from comparable workplaces

• Register for carcinogenic or germ cell mutagenic substances 1A/1B

  Retentionat least 40 years after exposure ends

• Register for reproductive toxicants 1A/1B

  Retentionat least five years after exposure ends

• Proof that the extract was handed over

  Retentionlike personnel records

When employees leave, they receive an extract with the data concerning them (Section 10a (2)). You can transfer retention and handover to the statutory accident insurance by sending the data to the competent accident insurance institution (Unfallversicherungsträger) or an association of these institutions (Section 10a (3)). The German Social Accident Insurance (DGUV) runs the Central Exposure Database (Zentrale Expositionsdatenbank, ZED) for this purpose; using it is voluntary and free of charge. Access to the data is available to the company doctor and the authority, to those affected for their own data and to employee representatives for data without personal reference (Section 10a (4)).

Notifying the authority and occupational health care

Activities with carcinogenic or germ cell mutagenic substances of category 1A or 1B where the occupational exposure limit is not met or that fall in the high-risk range must be notified to the competent authority in writing or electronically within two months of starting the activity – with the exposure determined and the action plan (Section 10a (5)). On request, you must also provide the authority with information such as the result of the substitution check, the quantities and the type and extent of exposure (Section 18 (3)).

• Mandatory health care (Pflichtvorsorge)

  Trigger under Annex Part 1 of the Ordinance on Occupational Health Care (ArbMedVV)Activities with the substances listed in para. 1 no. 1, such as benzene, chromium(VI) compounds or hardwood dust, if the substance is carcinogenic or germ cell mutagenic 1A/1B or the activity is designated as carcinogenic and repeated exposure cannot be ruled out

• Offered health care (Angebotsvorsorge)

  Trigger under Annex Part 1 of the Ordinance on Occupational Health Care (ArbMedVV)Activities with other carcinogenic or germ cell mutagenic substances 1A/1B where repeated exposure cannot be ruled out (para. 2 no. 2 (d))

• Follow-up health care (nachgehende Vorsorge)

  Trigger under Annex Part 1 of the Ordinance on Occupational Health Care (ArbMedVV)To be offered after activities with carcinogenic or germ cell mutagenic substances 1A/1B have ended (para. 3); transferred to the accident insurance institution with the person's consent when they leave (Section 5 (3) ArbMedVV)

Checklist: work with CMR substances

• CMR substances 1A/1B flagged in the hazardous substances register (H340, H350, H360, activities under TRGS 906)
• Substitution checked, decision against technically possible alternatives justified
• Closed system in place or exposure minimised in line with the state of the art
• Exposure measured or otherwise determined and assigned to a risk range
• Work areas demarcated, marked and access controlled
• Action plan drawn up if the exposure limit is exceeded or in the medium-risk range
• Notification of the authority within two months checked
• Exposure register up to date, exclusions justified, retention or ZED arranged
• Mandatory, offered and follow-up health care organised
• Operating instructions in place, employees instructed orally and instruction signed

Free templates for this guide

As PDF and Excel, free – to use in your own company.

• Hazardous substances

  Exposure register template (Excel & PDF) under Section 10a GefStoffV

  PDF + ExcelFree download
• Hazardous substances

  Asbestos checklist template (PDF) before work on existing buildings

  PDFFree download

Frequently asked questions