Hazard Communication, GHS, SDS, and PPE Integration

Hazard information must become field control

Hazard communication (HazCom) is the program that makes chemical hazards understandable before exposure occurs. Under the Globally Harmonized System (GHS) adopted by OSHA's revised 29 CFR 1910.1200, every hazardous chemical must carry a label with a product identifier, supplier, one of two signal words, hazard statements (H-codes), precautionary statements (P-codes), and the appropriate pictograms. The signal word Danger marks more severe hazards; Warning marks less severe ones.

There are nine pictograms (health hazard, flame, exclamation mark, gas cylinder, corrosion, exploding bomb, flame over circle, environment, and skull-and-crossbones).

A safety data sheet (SDS) has a fixed 16-section format. ASP candidates should know the order well enough to find information fast: Sections 1-3 (identification, hazards, composition), 4-6 (first aid, firefighting, accidental release), 7-8 (handling/storage, exposure controls/PPE), 9-11 (physical properties, stability/reactivity, toxicology), and 12-16 (ecological, disposal, transport, regulatory, other). Sections 12-15 are not enforced by OSHA but must still be present. Availability alone is not enough if workers cannot apply the data to the task.

PPE selection must follow the hierarchy of controls: elimination, substitution, engineering controls, administrative controls, then PPE last. If a vapor hazard can be cut by substitution, closed transfer, or local exhaust ventilation, those rank above relying on a respirator. When PPE is required, the selection must match the chemical, concentration, contact time, splash potential, route of entry, dexterity needs, and heat stress.

A common exam trap is choosing generic gloves or a dust mask without reading Section 8. Glove materials differ by permeation breakthrough time: nitrile resists many solvents and oils, butyl resists ketones, and natural rubber resists acids and bases but degrades in hydrocarbons. Worked example: if an SDS lists a chlorinated solvent with a measured breakthrough time of 30 minutes for nitrile, gloves must be changed well before that interval, not at the end of a four-hour shift. Respirator use additionally requires a written program, medical evaluation, and annual fit testing under 1910.134.

Procurement and management of change close the loop. A new cleaning chemical, resin, lithium battery type, coating, or reagent can create hazards the current procedure never addressed. Purchasing should trigger SDS review, compatibility checks, storage planning, training updates, and waste decisions before the material arrives on site. Contractors and temporary workers deserve special attention because they may bring their own chemicals.

Exposure limits and routes drive the controls

The exam expects you to connect hazard data to exposure limits and routes of entry. The four routes are inhalation, absorption (skin/eye), ingestion, and injection, with inhalation and skin absorption dominating most industrial exposures. OSHA enforces a permissible exposure limit (PEL) as an 8-hour time-weighted average; ACGIH publishes a threshold limit value (TLV) that is often more protective and updated more frequently, and NIOSH publishes a recommended exposure limit (REL). A short-term exposure limit (STEL) caps a 15-minute exposure, while a ceiling (C) value may never be exceeded at any instant.

When an SDS lists both a PEL and a lower TLV, the prudent program controls to the more protective number. Worked example: if a vapor has an OSHA PEL of 100 ppm but an ACGIH TLV of 25 ppm, monitoring that shows 60 ppm meets the legal PEL yet warrants additional controls because it exceeds the recommended TLV.

Labels also require attention to secondary containers. A chemical transferred into a spray bottle or beaker for immediate use by the person who filled it may be exempt from full labeling, but any container that leaves that person's control or shift must carry the product identifier and hazard information. Workplace-specific labeling systems such as HMIS or the older NFPA 704 diamond are permitted as supplements but cannot replace the GHS label elements on shipped containers.

Use this program check:

• Chemical inventory is current and tied to purchasing approval.
• Containers (including secondary/transfer containers) are labeled and compatible.
• The 16-section SDS is accessible and understood by affected workers.
• Exposure monitoring compares results against PEL, TLV, STEL, and ceiling values.
• Storage segregation, ventilation, spill kits, and eyewash match the hazards.
• PPE is selected from Section 8 data and verified in the field, not by habit.
• New or substituted materials trigger review before first use.