openapi: 3.1.0
info:
  title: ATSDR Toxic Substance Profiles Exposure Investigations Minimum Risk Levels API
  description: The ATSDR Toxic Substance Profiles API provides access to toxicological profiles, minimum risk levels, and health guidance for hazardous substances. Data covers chemical hazards, health effects, exposure routes, and regulatory standards maintained by the Agency for Toxic Substances and Disease Registry.
  version: '1.0'
  contact:
    name: ATSDR
    url: https://www.atsdr.cdc.gov/contact.html
servers:
- url: https://data.cdc.gov/resource
  description: ATSDR Data via CDC Open Data Platform (Socrata)
- url: https://www.atsdr.cdc.gov/api
  description: ATSDR Direct API
tags:
- name: Minimum Risk Levels
paths:
  /mrls:
    get:
      operationId: list-minimum-risk-levels
      summary: ATSDR List Minimum Risk Levels
      description: List ATSDR Minimum Risk Levels (MRLs) which are estimates of daily human exposure to hazardous substances that are unlikely to cause adverse health effects.
      tags:
      - Minimum Risk Levels
      parameters:
      - name: $limit
        in: query
        schema:
          type: integer
          default: 100
        description: Maximum number of results to return.
        example: 1
      - name: $offset
        in: query
        schema:
          type: integer
          default: 0
        description: Offset for pagination.
        example: 1
      - name: substance_name
        in: query
        schema:
          type: string
        description: Filter by substance name.
        example: Example Name
      - name: route
        in: query
        schema:
          type: string
          enum:
          - inhalation
          - oral
          - dermal
        description: Filter by exposure route.
        example: inhalation
      - name: duration
        in: query
        schema:
          type: string
          enum:
          - acute
          - intermediate
          - chronic
        description: Filter by exposure duration.
        example: acute
      responses:
        '200':
          description: List of minimum risk levels
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/MinimumRiskLevel'
              examples:
                ListMRLsResponse:
                  summary: List of minimum risk levels
                  value:
                  - substance_name: Benzene
                    cas_number: 71-43-2
                    route: inhalation
                    duration: chronic
                    mrl_value: 0.003
                    mrl_unit: ppm
                    year_updated: 2007
                  x-microcks-default: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
components:
  schemas:
    MinimumRiskLevel:
      type: object
      properties:
        substance_name:
          type: string
          description: Name of the hazardous substance.
          example: Example Name
        cas_number:
          type: string
          description: CAS registry number.
          example: example_value
        route:
          type: string
          enum:
          - inhalation
          - oral
          - dermal
          description: Exposure route.
          example: inhalation
        duration:
          type: string
          enum:
          - acute
          - intermediate
          - chronic
          description: Duration of exposure.
          example: acute
        mrl_value:
          type: number
          description: MRL value (units depend on route).
          example: 99.99
        mrl_unit:
          type: string
          description: Unit of measurement for the MRL value.
          example: example_value
        year_updated:
          type: integer
          description: Year the MRL was last updated.
          example: 1