What does the Latest Implementation of GHS in Mexico Entail?

October 21, 2015James Lee

On 9 October 2015, the Ministry of Labor and Social Welfare published and enacted a new Mexican Official Standard, NOM-018-STPS-2015, Harmonized System for the Identification and Communication of Hazards and Risks of Hazardous Chemicals in the Workplace (Sistema armonizado para la identificación y comunicación de peligros y riesgos por sustancias químicas peligrosas en los centros de trabajo).  NOM-018-STPS-2015 implements the fifth revised edition of the U.N. Globally Harmonized System of Classification and Labelling of Chemicals (5th Rev. GHS) in Mexico, and establishes a new mandatory scheme for hazard communication of chemical substances and mixtures in the Mexican workplace. 

Transitional Period

The standard has a transitional period of three years following its publication in the Mexican Official Gazette (Diario Oficial de la Federación (DOF)).  During the transitional period, employers must comply with the official standard NOM-018-STPS-2000, System for the Identification and Communication of Hazards and Risks of Hazardous Chemical Substances in the Workplace, or NOM-018-STPS-2014, Harmonized System for the Identification and Communication of Hazards and Risks of Hazardous Chemicals in the Workplace, which is an optional GHS standard.  Once the new standard NOM-018-STPS-2015 becomes enforceable and mandatory in October of 2018, the current standards NOM-018-STPS-2000 and NOM-018-STPS-2014 will be repealed.

Hazard Classification

Classification is to be based on the previous standard, NMX-R-019-SCFI-2011, harmonized system of classification and hazard communication of chemicals (Sistema armonizado de clasificación y comunicación de peligros de los productos químicos), which adopts all the health and physical hazard classification criteria for substances and mixtures as provided in GHS, and the 5th Rev. GHS.  In turn, the NOM-018-STPS-2015 adopts all building blocks of the 5th Rev. GHS.  NOM-018-STPS-2015 does not provide any list of harmonized classifications or pre-classifications like EU CLP or Canada HPR has done.

Unique Requirements

i. Label

The container label must be in Spanish and must have the following label elements: a) name of the hazardous chemical and mixture; b) signal word; c) appropriate pictograms; d) the hazard identification codes and hazard statements indicating physical and health hazards; e) the precautionary identification codes and precautionary statements for physical and health hazards. 

Unlike NMX-R-019-SCFI-2011, which requires the GHS pictogram size to be in 100 x 100 mm red bordered square set on a point frames, the new standard requires minimum pictogram sizes based on the distance of the observer from the label or sign:

Measure from one side of the diamond (cm) Minimum symbol height (cm) Maximum distance observing the label (m)
3.1 2.5 To 7
6.2 50 Up to 15
12.5 7.6 Up to 23
18.7 10.1 To 30
25.0 15.2 To 60
37.5 30.2 Greater than 60


For distances less than 7 meters, the employer must define the pictogram dimensions according to the size of the container or packaging, which must be legible. The pictogram sizes range from 3.1 to 37.5 centimeters, as measured along one side of the pictogram frame.

ii. Safety Data Sheet

The new standard requires the GHS 16 section safety data sheet (SDS), which may be written in free form but must be written in Spanish. The Ministry of Labor and Social Welfare does not regulate the content in sections 12-15 but it must comply with regulations of the responsible ministries.  

Other unique requirements for the SDS include:
a) The content must be clear and concise;
b) Use the symbols, acronyms and abbreviations, referred to in Chapter 5 of the Standard;
c) Provide complete information but in case of not having certain properties or it is technically impossible to provide all, clearly state such in each section;
d) Provide the date and issue number of the safety data sheet. If applicable, provide the revision date, and the indication of the version to be replaced;
e) Avoid using vague and ambiguous expressions;
f) Avoid using phrases such as "may be dangerous", "no health effects ", "safe in most conditions of use” or "harmless";
g) Number all pages, indicating the total number of pages within it. For example: "page one of three" or "Page 1 of 3", and
h) Indicate on each page the name of the substance or mixture.

iii. Training

The new standard also includes unique employee training requirements. Worker training is required: at least once a year; each time a new hazardous chemical or mixture is introduced; and when the safety data sheet and label are updated.

Differences between Mexico GHS Implementation and U.S. and Canada

Because NOM-018-STPS-2015 adopts the 5th Rev. GHS, the physical hazard classification category for aerosols is different from the U.S. OSHA HCS 2012 and Canadian WHMIS 2015.  In addition, NOM-018-STPS-2015 and NMX-R-019-SCFI-2011 do not forbid using the gases under pressure classification together with the aerosols classification.  Therefore, the gases under pressure classification for aerosols and standard aerosol classification may appear together on Mexican SDSs.  It is however important to note that the NMX classification guidelines are based on the 3rd Rev. GHS.  

Ecological toxicity classification disclosure is required under NOM-018-STPS-2015, which is non-mandatory in HCS 2012 and WHMIS 2015.  In addition, there is no separate classification criteria for “hazards not otherwise classified” or HNOC as implemented in the U.S. and Canada.  

It is unclear as to which framework for the mixture classification is required under NOM-018-STPS-2015 because it does not include any methods for the classification of mixtures. Instead, it simply references the voluntary NMX-R-019-SCFI-2011 standard. The NMX describes and allows both the higher and lower classification thresholds as outlined in GHS.  It is possible that Mexico will accept either the use of the lower classification thresholds adopted by the U.S. OSHA and Health Canada or the higher classification thresholds adopted in the EU.  

For more information, NOM-018-STPS-2015 can be found at: http://dof.gob.mx/nota_detalle.php?codigo=5411121&fecha=09/10/2015

Written by James C. Lee - 3E Company Sr. Regulatory Analyst for North America